<%BANNER%>
HIDE
 Title Page
 Table of Contents
 Letter from P. K. Yonge
 Letter of transmittal to chairman...
 Board of Control and Station...
 Report of auditor
 Report of plant physiologist
 Report of the entomologist
 Report of the plant pathologis...
 Report of the associate plant...
 Report of the laboratory assistant...
 Report of chemist
 Index


FLAG IFAS PALMM UF



Report for the fiscal year ending June 30th.
CITATION SEARCH THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00005184/00001
 Material Information
Title: Report for the fiscal year ending June 30th.
Physical Description: Serial
Language: English
Creator: University of Florida. Agricultural Experiment Station.
Publisher: University of Florida
Creation Date: 1916
 Subjects
Subjects / Keywords: Agriculture   ( lcsh )
Farm life   ( lcsh )
Farming   ( lcsh )
University of Florida.   ( lcsh )
Agriculture -- Florida   ( lcsh )
Genre: serial   ( sobekcm )
Spatial Coverage: North America -- United States of America -- Florida
 Notes
Funding: Florida Historical Agriculture and Rural Life
 Record Information
Source Institution: Marston Science Library, University of Florida
Holding Location: This collection includes the historic publications of the Florida Agricultural Experiment Station and the Florida Cooperative Extension Service, Institute for Food and Agricultural Services (IFAS), University of Florida. As IFAS documents are revised in the online EDIS system, replaced versions will be added to this collection. It also includes annual reports and bulletins from the Florida Department of Agriculture and Consumer Services and publications of the University of Florida Engineering and Industrial Experiment Station.
Rights Management: All rights reserved, Board of Trustees of the University of Florida
Resource Identifier: notis - AAA6469
oclc - 12029638
System ID: UF00005184:00001

Table of Contents
    Title Page
        Page 1
        Page 2
    Table of Contents
        Page 3
        Page 4
    Letter from P. K. Yonge
        Page 5
    Letter of transmittal to chairman of board of control
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
    Board of Control and Station Staff
        Page 6
    Report of auditor
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
        Page 25
        Page 26
        Page 27
        Page 28
        Page 29
    Report of plant physiologist
        Page 30
        Page 31
        Page 32
        Page 33
        Page 34
        Page 35
        Page 36
        Page 37
        Page 38
        Page 39
        Page 40
        Page 41
        Page 42
        Page 43
        Page 44
        Page 45
        Page 46
        Page 47
        Page 48
        Page 49
        Page 50
    Report of the entomologist
        Page 51
        Page 52
        Page 53
        Page 54
        Page 55
        Page 56
        Page 57
        Page 58
        Page 59
        Page 60
        Page 61
        Page 62
        Page 63
        Page 64
        Page 65
    Report of the plant pathologist
        Page 66
        Page 67
        Page 68
        Page 69
        Page 70
        Page 71
        Page 72
        Page 73
        Page 74
        Page 75
        Page 76
        Page 77
        Page 78
        Page 79
    Report of the associate plant pathologist
        Page 80
        Page 81
        Page 82
        Page 83
        Page 84
        Page 85
        Page 86
        Page 87
        Page 88
        Page 89
        Page 90
        Page 91
        Page 92
        Page 93
        Page 94
        Page 95
        Page 96
        Page 97
        Page 98
    Report of the laboratory assistant in plant pathology
        Page 99
        Page 100
        Page 101
        Page 102
        Page 103
        Page 104
        Page 105
        Page 106
        Page 107
        Page 108
        Page 109
        Page 110
        Page 111
        Page 112
    Report of chemist
        Page 113
        Page 114
        Page 115
        Page 116
        Page 117
        Page 118
    Index
        Index 1
        Index 2
        Index 3
        Index 4
Full Text
UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATION
REPORT FOR THE FISCAL YEAR ENDING JUNE 30th, 1916
May, 1917




CONTENTS
page
Letter of Transmittal to Governor of Florida.................................. 5R
Board of Control and Station Staff....................................................... 6R
Letter of Transmittal to Chairman of Board of Control................ 7R
Introduction .............................................................................................. 7R
Lines of Work......................................................."..................................... 7R
Publications................................................................................................ 12R
Report of Auditor................................................................................,.......... 13R
Report of Animal Industrialist.................................................................. 14R
Dairy Herd.................................................................................................. 14R
Experiments Conducted with Herd....................................................... 18R
Japanese Cane........................................................................................... 23R
Cowpeas, Yield of Forage and Grain..........-......................................... 24R
Velvet Beans.............................................................................................. 25R
Cotton and Sorghum Yields.................................................................... 26R
Replanting Japanese Cane..................................................................... 26R
Sweet-Potato Fertilizer Test................................................................. 28R
Report of Plant Physiologist...................................................................... 30R
Toxic Effect of Organic Chemicals on Citrus...................................... 30R
Effect of Vanillin on Citrus Cuttings.................................................. 36R
Injury to Citrus Trees by Ground Limestone.................................... 38R
Report of Entomologist............................................................................... SIR
Velvet Bean Caterpillar.......................................................................... 51R
Florida Flower Thrips.............................................................................. 51R
Combating Nematodes by the Use of Calcium Cyanamide................ 55R
Insects of the Year.................................................................................-- 64R
Report of Plant Pathologist...................................................................... 66R
Gummosis.................................-.................................................................. 66R
Melanose ...............................................................................-..........-........ 67R
Citrus Canker..........................................................................................--- 69R
*- Lightning Injury....................................................................-........ 74R
',' Lemon Brown Rot Fungus.......'.......................................................... 78R
Citrus Diseases.................................................................................. 79R
Report of Associate Plant Pathologist.................................................. 80R
Damping Off in the Seed Bed................................................................. 80 R
Seed Disinfection....................................................................................., 8BR
Buckeye Rot of Tomato Fruit..........................................:...........r 88R
Some Bacterial Diseases of Vegetables...................... 8pR
Other Diseases of Vegetables.............................,...............-------..... 80R
Report of Laboratory Assistant in Plant Pathology.......... 99R
Pecan Dieback...................................................................:.!.....-;......;-,- 99R
Leaf Blight of the Fig.......... .............................................-......... 108R
i Report of Chemist..............'............!................................................................ 113R
Citrus Experimental Grove...................................................................... 113R
Soil Tank Investigation............................................................................ 116R


4R
Contents
page
Bulletin 128.Citrus CankerIII. Pages 1-20.
Introduction ............................................................................................ .......... 3
History of Citrus Canker................................................................................... 4
Distribution in Florida................................................................................. 6
Appearance of Citrus Canker........................................................... 7
Cause of Citrus Canker.................................................................................... 12
Laboratory Investigations...................................................... ................ 14
Spread of the Disease....................................................................................... 18
Control............................................................................................................ 19
Bulletin 129.Japanese Cane. Pages 21-44.
Introduction ........................................................................................................' 25
Uses of Japanese Cane................................................................................... 26
Soil for Japanese Cane............................................................... .......... 28
Saving Seed Cane.......................................................................................... '29
Preparation of Seed Bed.................................................................................... 30
Cane for Planting.......................................... .................................................... 31
Planting............................................................................................................ 31
Cultivation......................................................................................................... 32
Harvesting............................................................................................................ 33
Japanese Cane and Velvet Beans..................................................................... 34
Fertilizer Experiment with Japanese Cane.................................................... 35
Storing Japanese Cane....................................................................................... 42
Replanting Japanese Cane.................................................................................. 43
Bulletin 130.Control of the Velvet Bean Caterpillar. Pages 45-60.
Introduction .......................................................................................................... 49
Life History of the Insect.................................................................................. 50
Migration and Distribution................................................................................ 51
Food of the Caterpillar........................................................................................ 52
Methods of Control.............................................................................................. 53
Bulletin 131.Pig Feeding. Pages 61-70.
Introduction .......................................................................................................... 63
Experiment I: Corn, Green Cowpeas, Green Sorghum.............................. 64
Experiment II: Corn, Peanuts, Rape............................................................ 65
Experiment III: Corn, Rape, Velvet Beans................................................. 66
Experiment IV: Corn, Velvet Beans, Iron Sulphate..,............................... 67
Experiment V: Corn, Dasheens, Velvet Beans............................................ 68
Press Bulletins 239.Bulletins and Reports on Hand. 240.Fertilizer Test of Sweet Potatoes. 241.The Time of Ripening of Velvet-Bean Varieties. 242.Feeding Test With Silage. 243.Avocado Propagation. 244.Avocado Culture. 245.Silage for Milk Production.
Index to Report, Bulletins, and Press Bulletins.


Hon. Sidney J. Catts,
Governor of Florida, Tallahassee, Fla.
Sir : I have the honor to transmit herewith the annual report of the Director of the Florida Experiment Station, for the fiscal year ending June 30, 1916.
Respectfully,
P. K. YONGE, Chairman of the Board of Control.
5R


Report for the Fiscal Year Ending June 30,1916
Hon. P. K. Yqnge,
Chairman, Board of Control.
Sir: I have the honor to submit herewith my report on the work and condition of the Agricultural Experiment Station for the fiscal year ending June 30, 1916, and I respectfully request that you transmit the same, in accordance with the law, to the Governor of the State of Florida.
Respectfully,
P. II. Rolfs,
Director.
Introduction
The unprecedented development of Agriculture in the State during the last year has called for an increasingly larger amount of information that the Experiment Station has been able to give. The work begun several years ago has been continued without interruption. Unfortunately it has been impossible, with the funds at our command, to cover all the lines of work that the agricultural people of the State are now demanding to be investigated. The Experiment Station staff has been called upon at numerous times to furnish exact data regarding various lines of investigation that have been carried on heretofore. Fortunately, all agricultural questions of a general nature can be referred to the Extension Division, thus freeing the Experiment Station staff from importunities excepting along the lines of its special investigations. The staff has been able to devote comparatively more time to investigational work of a broad nature than heretofore.
Lines of Work
The lines of work carried out during the last fiscal year have been essentially the same as those laid down some years ago. Portions of some of the Projects have been completed and publications issued on these.
IR


Plant Introduction Project.The Experiment Station has continued to cooperate with the United States Department of Agriculture in testing new and apparently valuable domesticated plants. The following twenty-seven grasses have given more or less promise in the several years test which they have undergone at the Experiment Station: Andropogon annulatus Melinis minutiflora
Andropogon barbindos Panicum molle (muticum) ?
Andropogon propinques Para Grass
Anthephora hermaphrodita Paspalum notatum Chaetochloa aurea Paspalum dilatatum
Chrysopogon montanus Panicum maximum
Capriola dactylon Panicum palmifolium
Cenchrus biflorus Panicum Capim de Angola
Cymbopogon rufus Panicum hirsutissimum
Eleusine coracana Pennisetum Ruppelianum
Erichloa subglabra Pennisetum purpureum
Eragrostis curvula Saccharum ciliare
Eragrostis chloromelas Sudan grass
Eragrostis abyssinica Tricholaena rosea
A number of these are already widely distributed in the State; others are being tested for forage value tho they are ordinarily used for ornamental purposes.
Especial attention has been given to the introduction and propagation of velvet beans. A number of these varieties have proved to be of special merit and have been distributed to various farmers in the State. Several varieties of the hybrid velvet beans, originated at the Experiment Station, have been continued in the plot grounds. These will be tried for a number of years more, with the possibility of some varieties proving superior to those now commonly grown.
Dairy Project.The principal work of the Animal Industry Department has been confined to testing the dairy herd and to the determination of the feed cost of milk when produced from Florida-grown forage. Accurate data has been kept as to the milk flow of each individual animal owned by the Experiment Station.
Somewhat extended tests'have been carried on in comparing the value of sorghum silage and Japanese-cane silage for wintering stock.
The new dairy barn has added greatly, to the value and accuracy of the work conducted in this line. A novel feature


in connection with this dairy barn is a concrete silo for the preservation of sweet-potato silage. The work conducted in this line shows that it is practicable to preserve sweet potatoes for cattle feeding and hog feeding purposes.
Plant Physiology Project.In the Department of Plant Physiology the work has been conducted along two principal lines: (1) Study of the toxic effects of certain organic chemicals when applied to certain growing citrus plants; and (2) a study of the effect of fertilizer combinations and sources upon the growth of citrus seedlings. The underlying subject with the Plant Physiologist is that of discovering the cause and securing a remedy for a very widely prevalent citrus disease known as dieback. When the problem was first approached it seemed as if it would be of rather easy solution, but the further the subject is studied the clearer it becomes that the question is an extremely complicated one. The analyses of soil taken from the region occupied by trees affected with this disorder show the presence of a considerable amount of vanillin; it was therefore thought that vanillin might have some causative relation to die-back. The rather careful and extended experiments made in this direction seem to throw considerable doubt on this hypothesis.
Another line of study that was taken up in the field is concerned with the value of ground limestone when applied to citrus groves. It had been noted that under certain limited conditions the effect following upon an application of ground limestone was deleterious to the grove. From rather extended field observations it appears quite clear that limestone, under certain limited conditions, induces injury to citrus trees which manifests itself in the form of chlorosis. The exact manner in which the lime produces this disadvantageous condition is still somewhat in doubt.
Entomology Project.The principal studies during the summer and fall of the past fiscal year were directed toward a full understanding of the life history and distribution of the velvet-bean caterpillar (Anticarsia gemmatilis). This work has been brought to a sufficient degree of advancement that it is thought probable this subject matter will be closed during the present fiscal year.
A considerable part of the time during the winter, spring an,d early summer was devoted to the study of flower thrips, especially, those thrins that cause greater or less injury to citrus,, tomatoes and other agricultural crops. In connection with


flower thrips, special attention was given to (1) the seasonal history and greater abundance in dry weather, and (2) greater extent of damage to citrus. Incidentally, several other forms of thrips were studied. It was also found that the flower thrips does not confine its entire activities to citrus.
Preliminary studies were begun on the use of Cyanamid and other material for combating root-knot, especially as to its usefulness under ordinary agricultural practice.
Plant Pathology Project.This Project concerns itself with three principal lines of work: (1) Diseases affecting citrus trees and fruit; (2) diseases affecting truck crops; and (3) diseases affecting the pecan tree and fruit.
In the citrus-disease work principal attention was given to the disease known as gummosis, the causative agent of which is not known. The subject is somewhat difficult to handle as the disease progresses rather slowly and it has been very difficult to ascertain the causative agent or agents.
A considerable amount of work has also been done in studying the bacterium causing citrus canker.
From time to time considerable uneasiness has been caused among citrus growers by the appearance in the grove of what seemed to be a rapidly developing disease. A number of times different pathologists of the Experiment Station have been called upon to give advice in this direction. On several different occasions the peculiar manifestation has been found to be lightning injury.
The principal work in truck diseases has been directed toward studying the disorder of seed beds usually spoken of as damping off." Studies on this problem have shown that it is by no means a simple question. It has also been shown that more good can be done in the preventive direction than in the direction of curing a seed bed after it is affected with damping off.
Somewhat extended attention has been given to the tomato disease popularly known as buckeye rot."
Careful attention has been given to the study of diseases affecting pineapple plants.
A somewhat extended and careful study has been made of the disease known as pecan dieback. This has been shown to be due to Botrysphaeria berengeriana. Methods of control have been introduced in extensive groves. By following up the prun-ing-out method considerable good can be done to trees severely affected with this disease. This wound parasite seems to be


unable to produce infection on uninjured surfaces of the pecan tree.
A new disease of the fig has been discovered and somewhat carefully studied. It has been shown to be due to a new species of fungus described under the name of Rhizoctonia microscle-rotia.
Soils and Fertilizers Project.In this Project the main attention during the year has been given to the study of fertilizers and to soil conditions as affected by fertilizers that have been applied to the Experiment Station grove during the last seven years. A considerable amount of time from the Chemist and Associate Chemist has also been given to the continuation of analyses of drainage waters from the lysimeter tanks on the Experiment Station grounds.
Plant Breeding Project.In the Plant Breeding Project, entire attention has been given during the last fiscal year to the further development of velvet-bean hybrids and the fixing of certain races and varieties. Attention has been given to further propagation of prominent varieties with a view to utilizing them as farm crops.
Changes in Station Staff.From July 1, 1915, to July 1, 1916, the following changes took place:
On October 1, Lewis Knudson, Ph.D., Cornell University, began temporary research work in the Laboratory of Plant Physiology. On October 31, John Schnabel resigned the position of Assistant Horticulturist. On October 31, C. D. Mc-Dowall, B.S., University of Florida, resigned the position of Laboratory Assistant in Plant Physiologist. On November 1, F. F. Halma, B.S., University of Florida, began work as Assistant Horticulturist. On December 31, A. C. Mason, M.S., University of Florida, resigned the position of Laboratory Assistant in Entomology. On December 31, Dr. Lewis Knudson completed the work he had been carrying on in the Laboratory of Plant Physiology. On January 1, H. L. Dozier, B.S., University of South Carolina, began work as Laboratory Assistant in Entomology. On June 30, John Belling resigned the position of Assistant Botanist and Editor.


Publications press bulletins
No. Title Date and Author
239 Bulletins and Reports on Hand............-.....................................Nov. 13, 1915
240 Fertilizer Test of Sweet Potatoes....................Feb. 12, 1916J. M. Scott
241 The Time of Ripening of Velvet
Bean Varieties............................................March 25, 1916J. Belling
242 Feeding Test with Silage....................................April 8, 1916J. M. Scott
243 Avocado Propagation.................................'.......April 23, 1916P. H. Rolfs
244 Avocado Culture................................................April 29, 1916P. H. Rolfs
245 Silage for Milk Production...............................May 20, 1916J. M. Scott
BULLETINS
128 Citrus Canker, III................................................Nov. 1915H. E. Stevens
129 Japanese Cane............................................................Jan. 1916J. M. Scott
130 Control of the Velvet Bean Caterpillar............June, 1916J. R. Watson
131 Pig Feeding..............................................................June,-1916J. M. Scott
ANNUAL REPORT for 1915; 131 pages, with index to all publications of the year.


BOARD OF CONTROL
P. K. Yonge, Chairman, Pensacola, Fla. T. B. King, Arcadia, Fla.
E. L. Wartmann, Citra, Fla.
W. D. FiNLAYSON, Old Town, Fla.
F. E. Jennings, Jacksonville, Fla.
J. G. Kellum, Secretary, Tallahassee, Fla.
STATION STAFF P. H. Rolfs, M.S., Director.
J. M. Scott, B.S., Animal Industrialist and Vice-Director.
B. F. Floyd, A.M., Plant Physiologist. J. R. Watson, A.M., Entomologist.
H. E.Stevens, M.S., Plant Pathologist.
C. D. Sherbakoff, Ph.D., Associate Plant Pathologist. S. E. Collison, M.S., Chemist.
John Belling, B.Sc, Assistant Botanist and Editor. S. S. Walker, M.S., Associate Chemist. F. F. Halma, B.S., Assistant Horticulturist. H. L. Dozier, B.S., Laboratory Assistant in Entomology. Julius Matz, B.S., Laboratory Assistant in Plant Pathology. ?Lewis Knudson, Ph.D., work in Plant Physiology. H. G. Clayton, B.S.A., Laboratory Assistant in Animal Industry. C. D. McDowell, B.S.A., Laboratory Assistant in Plant Physiology. T. VanHyning, Librarian. K. H. Graham, Auditor and Bookkeeper. E. G. Shaw, Secretary. L. T. Nieland, G.F., Farm Foreman.
?Temporary.
6/2


REPORT OF AUDITOR
P. H. Rolfs, Director.
Sir : I respectfully submit the following report of the credits received and expenditures vouchered out of the funds as specified:
receipts Other
Hatch Adams Sources
By balance on hand, July 1, 1915...................................................... $ 307.46
By Appropriation from U. S. Treasury........ $15,000.00 $15,000.00 ..................
By receipts, Sales Fund........................................................................ 2,977.10
State Experiment Fund...................................................................... 2,000.00
State Repair and Building Fund...................................................... 2,500.00
State Printing Fund................................................-........................... 3,750.00
Totals........................................................ $15,000.00 $15,000.00 $11,534.56
'-: v
expenditures -~
By
Salaries ........................ $ 8,296.68 $11,772.84 $ 266.67
Labor.................'................................................ 2,541.35 747.21 826.69
Publications...................................................... 714.72....................................
Postage and stationery.................................... 691.13 16.47 43.13
Freight and express........................................ 176.88 140.13 20.87
Heat, light, water, and power........................ 101.64 112.70 55.34
Chemicals and laboratory supplies................................. 651.73 ..................
Seeds, plants, and sundry supplies................ 156.16 323.08 100.84
Fertilizers............................................................................ 55-51 92-93
Feeding stuffs................................................... 1,245.22 .................. 806.45
Library.........................................................478.61 19.82 23.99
Tools, machinery and appliances.................... 125.80 137.02 186.48
Furniture and fixtures..................................... 84.63 99.66 ..................
Scientific apparatus and specimens................................ 87.17 ............_......
Livestock................................................................................................ 752.50
Traveling expenses________..........................-..... 24.60 777.98 31.03
Contingent expenses........................................ 342.58 .................. 3.80
Buildings and land..... .............................. 342.58 58.58 57.77
Balance................ ............ .............. -............................-...... 16.07
Totals............................................... $15,000.00 $15,000.00 $ 3,284.56
Respectfully submitted, / K. H. Graham,
Auditor.


REPORT OF ANIMAL INDUSTRIALIST
P. H. Rolfs, Director.
Sir: I submit the following report of the Department of Animal Industry for the year ending June 30, 1916.
Dairy Herd
During the year six grade and one purebred Jersey cows were added to the herd. The purebred Jersey cow was Creole's Lassie Sue No. 306835 by Fern's Blue Fox No. 83359, he by Sport of Oakhurst No. 72207, out of Belmont's Creole Girl No. 199448, out of Belmont Beulah No. 163856 by Tease's Golden Lad No. 57781.
No other animals were added to the herd except from the increase in calves. Only the most desirable heifer calves were retained. The grade bull calves were all sold for veal and two undesirable heifer calves were also disposed of. Two purebred Jersey bulls were sold within the year.
Elbertas' Eminent Fox No. 135708 was sold to the Florence Villa Fruit Co., Florence Villa, Florida, and Queen's Joyous Lad No. 134230 was sold to Ben T. Arnow, Gainesville, Florida.
The following table shows which cows dropped calves during the year, by which bull, and what disposition was made of the calf:
Fig. 1.Magnolia's Noble Pogis 131234.


TABLE 1
Dairy Herd Record
Table showing which cows dropped calves, by which bull, and what disposition was made of them.
Cow Name or Number
Fox's Primrose Jewel
No. 271802 Blandora No. 171373 Cow No. 14 Cow No. 27 Cow No. 22 Cow No. 4 Cow No. 23 Cow No 42 Cow No." 26 Cow No. 15 Cow No. 21 Cow No. 24 Cow No. 25 Cow No. 41 Cow No. 29 Oxford Lad's Jewel
No. 271481 Royal's Golden Belle
No. 310847 Cow No. 62 Cow No. 34 Cow No. 7 Cow No. 28 Cow No. 61 Cow No 9
Breed
Jersey
Jersey Grade Shorthorn Grade Jersey Grade Jersey Grade Jersey Grade Jersey Grade Jersey Grade Jersey Grade Jersey Grade Jersey Grade Jersey Grade Jersey Grade Jersey Grade Jersey
Jersey
Jersey Grade Jersey Grade Jersey Grade Jersey Grade Jersey Grade Jersey Grade Jersey
Date of Calving
Sept. 4, 1915 Nov. 11, 1915 Sept. 11. 1915 Sept. 30, 1915 Oct. 4, 1915 Oct. 2, 1915 Oct. 7, 1915 Oct. 11, 1915 Oct. 19, 1915 Nov. 13,1915 Nov. 15,1915 Nov, 1915 Dec."3, 1915 Dec. 19, 1915 Oct. 27, 1915
Feb. 24, 1916
Feb. 23, 1916 Feb. 9, 1916 Msiy 18, 1916 Apr. 14, 1916 May 31, 1916 Juno 13, 1916 Juno 5, 1916
Sire
Agatha's Agatha's Agatha's Agatha's Agatha's Agatha's Agatha's Agatha's Agatha's Agatha'E Agatha's Agatha's Elberta'i Agatha's Elberta'i
Gipsy Prince of K. Gipsy Prince of k, Gipsy Prince of K. Gipsy Prince of K. Gipsy Prince of K. Gipsy Prince of K. Gipsy Prince of K, Gipsy Prince of K. Gipsy Prince of K, Gipsy Prince of K. Gipsy Prince of K, Gipsy Prince of K, Eminent Fox No. Gipsy Prince of K Eminent Fox No.
V. F., No. V. F., No. V. F., No. :. V. F., No. V. F., No. V. F., No. :. V. F., No. :. V. F., No. :. V. F., No.
V. F., No. :. V. F., No. V. F., No. 135708 V. F., No. 135708
87041 87041 87041 87041 87041 87041 87041 87041 87041 87041 87041 87041
i. 87041
Agatha's Gipsy Prince of K. V. F., No. 87041
Elberta's Eminent Fox No. 135708
In calf when purchased
Agatha's Gipsy Prince of K. V. F., No. 87041
Elberta's Eminent Fox No. 135708
Elberta's Eminent Fox No. 135708
Elberta's Eminent Fox No. 135708
Affatha's Gipsy Prince of K. V. F., No. 87041
Sex
Heifer Heifer
Bull
Bull
Bull Heifer
Bull
Bull
Bull Heifer
Bull Heifer Heifer Heifer Heifer
Bull
Bull
Bull Heifer. Twin Bulls Heifer Heifer
Bull
Tattoo No. in left ear
64 66
67 68
Disposition
72 73
Retained, in herd
Retained in herd
Vea'ed
Vealed
Vealed
Vealed
Vealed
Vea'ei
Vealed
Vealed
Vealed
Vea.ed
Retainer! in herd Retained in herd Born dead
Retained in herd
Vealed Vealed
Retained in herd Vealed
Retained in herd Retained in herd Vealed
1
s
SO
O


Fig. 2.Prince Lanseer Tormentor 130913
The entire herd numbers 33 cows, 12 heifers, 9 calves and 3 bulls; a total of 57 head. Of this number 18 head are purebred Jerseys.
Table 2 gives age and breed of cows and time in milk.
TABLE 2
Age and Breed of Cows, and Time in Milk
.. when hened a
6 z BQ U b t) 08 & --5 S1
Cow So .< o $ h +J O) es *- Z.s *!
1 8 Grade Jersey Sept. 21, 1914 366
9 8 Grade Jersey Nov. 21, 1915 328 Apr. 30, 1916
15 7 Grade Jersey Nov. 13, 1915 160 Apr. 22, 1916
17 5 Jersey Sept. 4, 1915 297
18 5 Jersey Feb. 23, 1916 251 Nov. 2, 1915
20 5 Jersey May 31, 1915 366
21 4 Grade Jersey Nov. 15, 1915 225
22 4 Grade Jersey Oct. 4, 1915 126 Feb. 9, 1916
24 4 Grade Jersey Dec. 5, 1915 206
25 4 Grade Jersey Dec. 3, 1915 318
26 4 Grade Jersey Oct. 19, 1915 302 -
41 4 Grade Jersey Dec. 19, 1915 277 Sept. 22, 1915
59 3 Jersey Apr. 9, 1915 350
60 12 Grade Jersey Grade Jersey 329
61 7 160 Dec. 24, 1915
62 3 Grade Jersey 277 Dec. 17, 1915
63 ; 7 Grade Jersey 248 Apr. 21, 1916
65 7 Grade Jersey 210 Apr. 19, 1916
69 3 Grade Jersev Jan. 2, 1916 181


Table 3 shows the amount of milk and butter per cow from July 1, 1915, to June 30, 1916.
TABLE 3
Record July 1, 1915, to June 30, 1916
Table showing cow number, pounds of milk, percent of butter fat, pounds of butter, value of butter at 40 cents per pound, gallons of milk, value of milk at 32 cents per gallon, cost of feed, and profit over cost of feed.
Cow No. Pounds of Milk Percentage of Butter Fat Pounds of Butter Fat Valuo of Butter at 40c per lb. Gallons of Milk Value of Milk at 32c per Gallon Cost of Feed Profit over Cost of Feed
5133.9 6.5 337.35 $157.43 596.9 $191.00 $ 82.34 $108.66
Jj ^907.7 6.0 360.75 168.35 686.9 219.81 94.86 124.95
449.0 4.5 66.28 30.93 168.5 53.92 33.57 20.55
n1 2404.0 5.1 123.40 57.59 279.5 89.44 54.76 34.68
18 3248.9 5.5 179.43 83.76 377.7 120.86 42.85 78.01
20 4613.7 4.8 224.30 104.67 536.5 171.68 101.52 70.16
21 4009.6 4.6 185.45 86.54 466.2 149.18 50.85 98.33
22 1181.4 4.3 51.40 23.99 137.4 43.97 22.07 21.90
24 2540.1 5.7 145.54 67.92 295.4 94.53 43.89 50.64
25 3178.1 5.8 186.81 87.18 369.5 118.24 46.53 71.71
26 3205.3 5.6 182.49 85.16 372.7 119.26 57.94 61.32
41 3626.3 5.4 196.27 91.59 421.7 134.94 49.07 85.87
59 4840.5 5.5 267.53 124.85 562.8 180.09 78.46 101.63
60 4537.9 4.8 219.86 102.60 527.6 168.83 78.87 89.96
61 1813.6 5.5 100.68 46.98 210.9 67.49 30.42 37.07
62 3004.2 5.5 167.77 78.29 349.3 111.78 47.37 64.41
63 2960.1 4.3 129.82 60.58 344.2 110.14 66.34 43.80
65 2174.6 4.9 107.38 50.11 252.8 80.89 40.36 40.53
69 3746.2 4.0 150.15 70.07 435.6 139.39 35.86 103.53
Fig. 3.Purebred and grade Jersey heifers raised on the Experiment Station farm.


table 4 Daily Rations per Cow.
Lot i. Lot ii.
Feeds Used Pound? Feeds Used Poundi
Wheat Bran........................ 7.6 3.8 15.0 Wheat Bran....................... 7.6 3.8 15.0
Cottonseed Meal................ Sorghum Silage.................. Cottonseed Meal............... Japanese-cane Silage
During the first period each lot of cows were fed the fore going ration. During the second period the feeds were re versed; that is, lot I received the rations given lot II durinj the first period and lot II were given the rations fed lot I durinj the first period. During the third period each lot of cows received the same ration as in the first period. During th( fourth period each lot of cows received the same ration as ir the second period.
The sorghum-silage ration produced 539.72 gallons of milk ai a total feed cost of 12.1 cents a gallon. The Japanese-cam silage ration produced 509.74 gallons of milk at a total feed cos' of 12.8 cents a gallon. This makes a difference of feed cost pe] gallon of 0.7 of a cent in favor of sorghum silage.
A record of the weight of each animal was taken at the be ginning of the experiment and at the close of each period. Th< weights of the cows varied but little during the experiment. Al cows made a slight gain over the average weight at the beginning. This would indicate that there was no difference betweer these two rations in maintaining the animal's initial weight.
The following gives the results in detail:
Experiments Conducted With Herd
Two experiments in milk production were conducted durinj the year.
sorghum silage and japanese-cane silage compared
The first was a comparison of sorghum silage and Japanese cane silage for milk production. The experiment began Jan uary 18 and ten cows were used in the test. These ten cowi were divided into two lots of five each. The experiment wa: divided into four periods of 16 days each, with four days be tween each period for changing feeds.


TABLE 5 Feeds Consumed and Milk Produced First Period, January 18 to February 2, 1916.
Lot I
Feeds Used Pounds
Cottonseed meal........................ 304.0
Bran .......................................... 608.0
Sorghum Silage........................ 1200.0
Milk produced............................ J.202.2
Lot II
Feeds Used Pounds
Cottonseed meal........................ 304.0
Bran .......................................... 608.0
Japanese-cane Silage.............. 1200.0
Milk produced............................ 1077.6
Second period, February 6 to February 21, 1916
Cottonseed meal........................ 304.0 Cottonseed meal...................... 304.0
Bran .......................................... 608.0 Bran .......................................... 608.0
Japanese-cane Silage.............. 1200.0 Sorghum silage........................ 1200.0
Milk produced.......................... 1152.2 ; Milk produced............................ 1159.1
Third period, February 25 to March 11, 1916.
Cottonseed meal........................ 304.0
Bran.......................................... 608.0
Sorghum silage........................ 1200.0
Milk produced.......................... 1201.0
Cottonseed meal........................ 304.0
Bran .......................................... 608.0
Japanese-cane silage................ 1200.0
Milk produced.......................... 1100.8
Fourth period, March 15 to March 30, 1916.
Cottonseed meal........................ 304.0 j Cottonseed meal........................ 304.0
Bran .......................................... 608.0 Bran .......................................... 608.0
Japanese-cane silage................ 1200.0 j Sorghum silage........................ 1200.0
Milk produced............................ 1053.2 j Milk produced...................:........ 1079.3
Feed Cost per Gallon of Milk Cows fed sorghum silage.
1216 pounds cottonseed meal @ $30 a ton.......................................$18.24
2432 pounds wheat bran @ $31 a ton........................................$37.70
4800 pounds sorghum silage @ $ 4 a ton........................................$ 9.60
Total cost of feed...............................................................................$ 65.54
Milk produced539.72 gallons @ $ .32........................................$172.71
Cost per gallon............................................................................$ .1214
Cows fed Japanese-cane silage.
1216 pounds cottonseed meal @ $30 a ton..........................].............$18.24
2432 pounds wheat bran @ $31 a ton........................................$37.70
4800 pounds Japanese-cane silage @ $ 4a ton........................................$ 9.60
Total cost of feed................................................................................$ 65.54
Milk produced509.74 gallons @ $ .32........................................$163.10
Cost per gallon............................................................................$ .1285


TABLE 6
Weights of Cows January 19, 1916, Beginning of first period.
Lot I Pounds j Lot II Pounds
Cow No. 60 Z!........ 750.0 Cow No. 26............................ 648.0
Cow No. 25 ................... 508.0 Cow No. 20............................ 795.C
Cow No. 9........................... 893.0 Cow No. 21............................ 763.0
Cow No. 24........................... 622.0 Cow No. 59............................ 576.0
Cow No. 41............................ 611.0 Cow No. 1............................ 938.0
Average............................676.8 Average............................744.0
February 2, 1916, End of first period.
Cow No. 60............................ 726.6 Cow No. 26............................ 641.
Cow No. 25............................ 495.0 Cow No. 20............................ 779.0
Cow No. 9.......................... 886.6 Cow No. 21........................... 753.3
Cow No. 24.....:...................... 618.6 Cow No. 59............................ 553.3
Cow No. 41............................ 625.6 Cow No. 1............................'898.0
Average.............:............ 670.5 Average.......................... 725.
February 22, 1916, End of second period.
Cow No. 60............................ 733.3 Cow No. 26.............-............... 650.0
Cow No. 25............................ 517.3 Cow No. 20................... 805.0
Cow No. 9............................ 888.3 1 Cow No. 21........................ 756.6
Cow No. 24............................ 629.6 Cow No. 59............................ 576.6
Cow No. 41............................ 635.0 Cow No. 1...................... 918.3
Average ........................ 680.7 i Average ........................ 741.3
March 11, 1916, End of third period.
Cow No. 60............................ 734.0 Cow No. 26.......... 662.3
Cow No. 25............................ 521.6 Cow No. 20.................. 803.3
Cow No. 9............................ 896.6 Cow No. 21.................... 769.0
Cow No. 24............................ 633.3 Cow No. 59....... 567.3
Cow No. 41............................ 643.3 Cow No. 1................. 930.0
Average ...................... 685.8 Average ........................ 746.4
March 30, 1916, End of fourth period.
Cow No. 60............................ 740.6 \ Cow No. 26.......... 6783
Cow No. 25............................ 528.3 Cow No. 20......... 816 6
Cow No. 9............................. 918.3 Cow No. 21.................... 763.3
Cow No. 24............................ 630.0 Cow No. 59................ 596 6
Cow No. '1............................ 680.0 Cow. No. 1................. 925 0
Average ...................... 699.4_Average ........................ 756.0
SORGHUM SILAGE AND SWEET-POTATO SILAGE COMPARED
The second experiment was a comparison of sorghum silage and sweet-potato silage for milk production.
Ten cows were selected from the dairy herd and divided into two lots. The two lots of cows were as nearly equal in all


respects as it was possible to get them. The test began May 9 and continued for 43 days, closing June 20. The test was divided into two periods of 20 days with three days between periods for the purpose of changing feeds.
The following table gives the daily ration fed each cow in each lot.
TABLE 7 Daily Ration per Cow
Lot I
Feeds Used Pounds
Wheat Bran...................... 8.42
Cottonseed meal.............. 2.80
Sweet-potato silage.......... 10.60
Lot II
Feeds Used | Pounds
Wheat Bran...................... I 8.42
Cottonseed meal.............. < 2.80
Sorghum silage................ i 15.20
During the first period each lot of cows were fed the foregoing ration. During the second period the feeds were reversed ; that is, lot I received the rations given lot II during the first period and lot II received the rations given lot I during the first period.
The'sorghum-silage ration produced 280.9 gallons of milk at a total feed cost of 14.8 cents per gallon.
The sweet-potato silage ration produced 307.1 gallons of milk at a total feed cost of 15.4 cents per gallon. This shows a difference of 0.6 of a cent per gallon in favor of sorghum silage.
TABLE 8 Feeds Consumed and Milk Produced
First period, May 9 to May 29, 1916. Lot I I Lot II
Feeds used Pounds | Feeds used Pounds
Wheat bran............................ 842.0 Wheat bran......................... 842.0
Cottonseed meal.................... 280.0 Cottonseed meal.................... 280.0
Sweet potato silage..-.......... 1060.0 Sorghum silage..................... 1520.0
Milk Produced........................ 1310.9 Milk produced........................ 1202.2
Second period, June 1 to June 20, 1916.
Wheat bran............................ 842.0 j Wheat bran............................ 842.0
Cottonseed meal.................... 280.0 [ Cottonseed meal.................... 280.0
Sorghum silage...................... 1520.0 Sweet-potato silage.............. 1060.0
Milk produced........................ 1213.7 I Milk produced........................ 1330.1


Feed Cost per Gallon of Milk Cows fed sweet potato silage.
Wheat bran............................... 1684 pounds @ $31.00 a ton................ $26.10
Cottonseed meal........................ 560 pounds @ $30.00 a ton................ $ 8.40
Sweet potato silage.................. 2120 pounds @ $13.00 a ton................ $13.98
Total cost of feed................................................................................... $48.48
Total milk produced, pounds.................................................................... 26.41
or, gallons ..................................................................................................307.1
Feed cost per gallon......,...................................................................$ .158
Cows fed sorghum silage.
Wheat bran................................ 1684 pounds @ $31.00 a ton................ $26.10
Cottonseed meal______................. 560 pounds @ $30.00 a ton................ $ 8.40
Sorghum silage.......................... 3040 pounds @ $ 3.00 a ton................ $ 6.08
Total cost of feed.......................................................................................$40.58
Total milk produced, pounds................................................................ 2415.9
or, gallons ................................................................................................ 280.9
Cost per gallon....................................................................................$ .144
TABLE 9 Weight of Cows
May 9, 1916, Beginning of first period.
Lot I
Pounds
Cow No. Cow No. Cow No. Cow No. Cow
No.
21.......................... 787:3
18............................ 697.3
26............................ 715.0
31............................ 525.0
62............................ 570.0
Lot II
Pounds
Cow No. Cow No.
41.. 69..
Cow No. 25.. Cow No. 24.. Cow No. 20..
667.3 715.0 543.0 660.0 870.0
May 28, 1916, End of first period.
Fed sweet-potato silage
Cow No. 21.....................:...... 781.6
Cow No. 18............................ 706.6
Cow No. 26............................ 733.3
Cow No. 31............................ 553.3
Cow No. 62............................ 601.6
Fed sorghum silage.
Cow No. 21............................ 882.3
Cow No. 18............................ 710.6
Cow No. 26............................ 748.0
Cow No. 31............................ 588.0
Cow No. 62............................ 613.3
Fed sorghum silage.
Cow No. 41............................ 661.6
Cow No. 69............................ 729.0
Cow No. 25............................ 555.0
Cow No. 24........................... 678.0
Cow No. 20............................ 886.6
Fed sweet-potato silage.
Cow No. 41............................ 684.6
Cow No. 69............................ 722.3
Cow No. 25............................ 583.3
Cow No. 24............................ 674.6
Cow No. 20............................ 902.3
June 20, 1916, End of second period.
Test for Tuberculosis
On May 27, 1916, the entire dairy herd was tested for tuberculosis by Dr. W. A. Munsell of the State Board of Health. Not an animal in the herd reacted. The herd has been tested several times within the last ten years. So far, we have never had a case of tuberculosis on the Station farm.


Comparison of Sorghum Silage and Japanese-Cane Silage for Wintering Cattle
An experiment was begun. December 8, 1915, and continued for sixty days, to compare the value of sorghum silage and Japanese-cane silage for feeding young cattle during the winter.
The experiment was not planned with any idea of fattening the animals. The main object was to see if the animals would maintain their initial weight during the winter when fed on silage and a small allowance of cottonseed meal.
The animals used in this test were grade Jersey heifers from fifteen to thirty months old.' They were divided into two lots, as nearly equal in weight and quality as possible. Those in lot I were fed all the sorghum silage they would eat, about thirty pounds each, and one pound of cottonseed meal each, daily. Those in lot II were fed an equal amount of Japanese-cane silage and one pound of cottonseed meal daily.
The animals fed sorghum silage and cottonseed meal for sixty days gained an average of 8.25 pounds each. Those fed on Japanese-cane silage and cottonseed meal just maintained their weight.
Hogs.
Since the last report, the Berkshire boar, Handsome Lee's Baron 3d No. 215322 was bought. Handsome Lee's Baron 3d No. 215322 was sired by Handsome Lee's Rival No. 133488 and out of Maramech's Matchless Lady 3d No. 184977. This boar has already proven himself a good breeder.
Japanese-Cane Fertilizer Experiment
Two crops have been harvested from the Japanese-cane fertilizer experiment. The results obtained up to this time are not sufficient to warrant drawing any definite conclusions. There is one very noticeable fact brought out when the yields per acre obtained in 1915 are compared with the yields obtained in 1914. There is a very noticeable decrease. The decrease in some plots is more than 50 percent. On some of the plots the decrease in yield was not more than 10 to 20 percent. These results are very similar to data obtained in a previous fertilizer experiment with Japanese cane (see Fla. Agr. Exp. Sta. Bui. 129). That is, there was a gradual decrease in yield after the first year.


TABLE 10 Japanese-Cane Fertilizer Experiment
^2 S 3
Fertilizer applied, pounds per acre
o
1........
2........
3........
4........
5........
6........
7........
8........
9*......
10........
11........
12........
13........
14........
15........
16.....:..
17........
18........
19........
20*......
21........
22........
23........
o
2
II
o
pq g
84 I
84 84 i, 84 i. 84;.
"84 i'. 84'.
123.5 "l23.5
CD C3 &
C
p.
2
rC C3 Pi O
S
W o
30f I
84
123.5 123.5 j
116.6 i
84
123.5
116.6 :
150
150........
i
75
ns
o h
o
CD -P
I P. cj CO p,
150
75
75 75
75
133
150 j..
133
60 60
"60 60 60 60 60
60 60 60
"60
4> . p

<5l
Yield per acre, tons
green material
1914
2000 2000
2000 2000
17.03 14.42 32.67 12.31 15.97 17.11 16.85 16.68 9.63 12.77 14.38 13.41 14.11 9.02 12.10 9.14 9.09 6.79 8.40 6.67 7.05 14.03 9.45
1915
*Check plots. fLoads.
Cowpeas, Yield of Forage and Grain
Four varieties of cowpeas were tested last year for yield of forage and also yield of seed. The varieties used were Monetta S. P. I. No. 1541, Brabham, S. P. I. No. 27863, and S. P. I. No. 27864.
TABLE 11
Cowpeas; Yield of Forage and Grain
Yield of Forage, Yield of Seed in Pods,
Variety Pounds per acre. Pounds per acre.
Monette S. p. i. No. 1541.......................... 1705.1 531.7
Brabham ...................................................... 1577.9 517.3
S. P. I. No. 27863.......................................... 327.0 258.2
S. p. i. No. 27864.................;...................... 301.3 ........
The results of this year's work indicate that Monette S. P. I. No. 1541 has given best results. However, there is but little


difference in the yield of seed in pod between the Monette and Brabham.
Chinese Velvet-Bean Fertilizer Test One acre of Chinese velvet beans were used for a fertilizer test. The acre was divided into six plots of equal size. One row was left between each plot so that the fertilizer on one plot would have no effect on the adjoining plot. The beans were all planted at the same time, April 12, 1915, and the fertilizer was applied April 30, 1915.
TABLE 12
Chinese Velvet-Bean Fertilizer Experiment
Yield per acre
Plot Fertilizer applied Pounds Beans in Pod,
Number Per acre Pounds
1................................Ground Limestone ..........................2,000 596.4
2...............................Check ........................................................ 616.0
3................................Thomas slag .................................- 360 658.4
4.......................:........Acid phosphate .........,...................... 400 583.9
5................................Check................................................... 642.8
6................................Raw phosphate ................................ 200 601.8
These results indicate clearly that an application of ground limestone or fertilizer has no effect on increasing the yield of Chinese velvet bean seed, there being a difference in yield of only 84.4 pounds per acre between the highest and lowest yields. The highest yield, 658.4 pounds, was obtained from plot 3, to which Thomas slag was applied. Plot 5, to which no fertilizer was applied, produced a yield of 642.8 pounds, a difference of only 15.6 pounds per acre in favor of the Thomas slag. This small difference is easily within the limit of error.
Velvet Beans, Yield per Acre
Several acres of velvet beans were grown last year to determine the yield per acre of beans in the pod. The results show quite a variation in yield for the different varieties.
Each of these varieties were grown on acre plots and the entire acre was harvested and weighed. This really gives actual field results. A much larger yield can be obtained when grown on small areas and the yield then reckoned per acre.
Yield of Velvet Beans
Yield per acre
Variety in Pods, Pounds
Chinese............................................................................................ 1229.5
Florida................................................................................................ 1320.0
Wakulla .............................................................................................. 856.0
Osceola ................................................................................................ 1394.6
Yokohama .......................................................................................... 1893.0


Sulphate of Ammonia .......................................................................... 50 pounds
Sulphate of Potash ................................................................................ 50 pounds
Acid Phosphate..................................................................................... 175 pounds
Total.................................................................................................. 275 pounds
The work of selection is being continued.
Sorghum Yield
The following figures show the yield of sorghum produced on the Station farm, as green forage, dry forage, and the yield of seed in the heads:
Green Weight Dry Weight
Variety Pounds per Acre Pounds per Acre
Sumac, Seed Heads............................................ 1236.25 1129
Sumac, Forage .............................;...................... 9512.00* *3037
*Average of two acres.
Replanting Japanese Cane
Heretofore the general opinion has been that Japanese cane will continue to produce good yields of forage for an indefinite period. From the results of experiments conducted during the last eight years we have found that the yield of green material decreased each year after the first year. We have no theory as to why there is a decrease in yield each year. If the decrease in yield was due to soil exhaustion this could be shown by replanting the cane. Replanting the cane should show no increase in yield if the decrease in yield was due to soil exhaustion.
A plot of ground was selected in the spring of 1915 that had grown Japanese cane continuously since 1908. This plot had been used for Japanese-cane fertilizer experiments from 1909 to 1914 inclusive, hence we had a complete record of the fertilizer applied and yield obtained each year.
The following table shows the amount of fertilizer applied per acre and the yield in tons of green material per acre each year since 1909 to 1914 inclusive:
Cotton, Yield per Acre
Four acres of cotton were grown last year. The four acres produced a total yield of 1,398 pounds of seed cotton, or an average yield per acre of 349.5 pounds. The yield on these four acres varied greatly. The highest acre yield was 497 pounds and the lowest was 210 pounds of seed cotton.
The following amounts of fertilizer were applied, per acre :


TABLE 13
Japanese-Cane Fertilizer Test, 1909 to 1914
Fertilizers, pounds per acre
Fertilizer Plot 1 Plot II Plot III : Plot IV Plot V Plot VI Plot VII Plot VIII
"(Dried blood ........... 112 112 112 112 112
JSulph. of ammonia Muriate of potash.... Sulphate of potash.. Acid phosphate ... 72 84 "224" 72
84 84 "224" 84 "224"
"224: 84 224 84 224 84 224 2000
* Ground limestone..
Yield, in tons of green material per acre
1909 .......................... 24.20 17.70 16.10 19.10 19.54 18.90 16.60 27.03
1910 .......................... 14.60 12.40 10.00 14.40 11.80 16.70 14.10 16.00
1911 .......................... ..7.08 9.00 9.63 14.36 13.56 15.48 14.02 14.10
1912 .......................... 6.38 6.84 3.68 7.92 7.26 9.62 10.68 10.28
1913 .......................... 8.16 6.93 3.83 8.51 8.09 7.86 9.33 8.92
1914.......................... 5.31 5.05 2.07 6.87 5.25 6.73 7.26 5.89
Average for 6 years 10.95 9.65 7.55 11.87 10.91 12.54 11.99 13.70
* Ground limestone was applied in 1909, 1911, and 1913.
fThe dried blood contained 16 percent of ammonia.
JThe sulphate of ammonia contained 25 percent of ammonia.
After growing Japanese cane on this plot for six years it was plowed up. On March 6, 1915, a part of each of the eight plots was replanted with Japanese cane. The new cane was planted in the same rows that had grown cane for six years. Each plot of the replanted Japanese cane was fertilized in the same way as the plots had been for the previous six years. (See foregoing table.)
The following yields per acre of green material were obtained from each plot in the fall of 1915:
Tons
Plot 1 .................................................................................................................. 29.5
Plot II............................................................................................................... 31.9
Plot III............................................................................................................... 18.0
Plot IV ............................................:................................................................... 24.2
Plot V.................................................................................................................. 29.7
Plot VI ................................................................................................................ 24.9
Plot VII.............................................................................................................. 27.3
Plot VIII* .....................:..............................................................:..................... 22.5
* Ground limestone was applied in 1915 at the rate of 2000 pound's per acre.
The replanted cane produced a better yield than the field had produced before. One would have thought after growing Japanese cane for seven years that the soil would have been almost exhausted. This, however, did not appear to be so. The ratoon cane does not produce as heavy a yield of green material per acre as does the planted cane. These results indicate strongly the advisability of replanting Japanese cane every three or four


years. All of the plots, except Plot III, gave satisfactory yields. There is but little difference in the yields produced by Plots I, II, and V. Plot II, which had received no ammonia for seven years, gave the heaviest yield of green material per acre. Plot
111, which had received no potash during the past seven years, gave a yield of only 18 tons of green material per acre. This is a marked decrease in yield as compared with that of any of the other plots. This shows the need of potash in a fertilizer to produce the best yields of Japanese cane.
The yields of Plots IV and VI are nearly equal. Plot VII produced a yield of 27.3 tons, which is 4.8 tons more green material than the yield of Plot VIII. This tends to show that no benefit was obtained from the applications of ground limestone, except from the first application in 1909.
Sweet-Potato Fertilizer Test
The land on which this test was conducted had grown Japanese cane for seven consecutive years. The eight plots of Japanese cane for six years had had the same amounts and kinds of fertilizer applied to each plot each year as were applied to the plots of sweet potatoes in the experiment. After the plots had grown Japanese cane for seven years it is likely that the soil of these plots in which any one fertilizer element was omitted was more or less exhausted for that particular element. Therefore, these results should be considered of some importance as a source of additional information in regard to fertilizing sweet potatoes.
The land on which the experiment was conducted was what would be called a fair grade of high pineland.
fertilizers used
The same number of pounds of fertilizer was not applied to every plot, but each plot received the same number of pounds of plant food of each element. The following amounts of fertilizer were applied per acre: Plot I; dried blood, 112 pounds, and muriate of potash, 84 pounds. Plot II; acid phosphate, 224 pounds, and muriate of potash, 84 pounds. Plot III; dried blood,
112, and acid phosphate, 224 pounds. Plot IV; sulphate of ammonia, 72, acid phosphate, 224, and muriate of potash, 84 pounds. Plot V; dried blood, 112, acid phosphate, 224, and muriate of potash, 84 pounds. Plot VI; sulphate of ammonia, 72, acid phosphate, 224, and sulphate of potash, 84 pounds. Plot


VII; dried blood, 112, acid phosphate, 224, and sulphate of potash, 84 pounds. Plot VIII; dried blood, 112, acid phosphate, 224, sulphate of potash, 84, and ground limestone, 2,000 pounds.
The first three plots received incomplete fertilizers, the next four plots were given a complete fertilizer, and the eighth plot had a complete fertilizer together with ground limestone. The fertilizer was divided and given in two equal applications. The first application was made on May 4, and the second on August 19. Triumph sweet potato draws were planted on May 10, in rows six feet apart, and were set sixteen inches apart in the row. -
results
The yields per acre were obtained by weighing the sweet potatoes from each plot and figuring them at 60 pounds per bushel. The yields are given in bushels per acre.
Plot I, 245.6; plot II, 221.6; plot III, 99.6; plot IV; 259.6; plot V, 252.0; plot VI, 216.0; plot VII, 222; and plot VIII, 269.6 bushels.
It will be seen from these figures that the best yield was obtained from plot VIII, which was fertilized with dried blood, acid phosphate, and sulphate of potash, and in addition ground limestone. However, the yield from plot IV, which was fertilized with sulphate of ammonia, acid phosphate, and muriate of potash, was nearly equal to that of plot VIII.
The yields obtained from plot I, omitting phosphate, and plot II, omitting ammonia, are rather surprising, being about equal to those obtained from any of the four complete fertilizers. Plot III gave less than one half the yield produced by any of the other plots in the experiment. This indicates strongly the need of potash in the fertilizer to produce a satisfactory yield of sweet potatoes. Even plot II that received no ammonia, gave more than twice the yield of plot III.
Respectfully,
John M. Scott, Animal Industrialist.


REPORT OF PLANT PHYSIOLOGIST
P. H. Rolfs, Director.
Sir : I submit the following report of the Plant Physiologist for the fiscal year ending June 30, 1916.
The two particular lines of work to which attention has been given during this fiscal year are: (1) The study of the toxic effects of certain organic chemicals; and (2) a study of the effect of fertilizer combinations and sources upon the growth of citrus seedlings. The latter is a continuation of work that has been under way since 1913.
Toxic Effect of Organic Chemicals on Citrus
The study of the toxic effect of certain organic chemicals on citrus is a phase of the work in connection with the study of the citrus disease, Dieback. Since this disease is brought on either directly or indirectly by organic nitrogenous fertilizers (Fla. Agr. Exp. Sta. Rep., 1912, p. cii) the working theory has been adopted that the disease is induced directly by the toxic effect of certain decomposition products arising from the decay of these organic materials under certain limited conditions. In adopting this theory, the possibility is recognized that the disease may be due to the attack of some parasitic organism and that the method of feeding the plant merely develops susceptibility. But the study of the disease thus far has not supported this possibility.
The disease, Dieback, manifests itself by the presence of gum in different tissues of the plant. In the absence of the gum symptoms, the disease can not be recognized. It is presumed that the cause of the disease is one that induces gum formation, and that it is this production of gum with its various accompanying secondary physiological disturbances that constitutes the disease, Dieback.-
From a study of the literature of gum formation in other plants, it is probably safe to conclude that all gum formation is, in its last analysis, the result of processes in living cells induced by chemicals from without. The chemicals may be enzymes or other compounds from fungi, bacteria or other organisms growing within or attacking the tissues; or they may be chemicals originating within the plant from autolytic processes; or chemicals introduced into or absorbed by the plant.
Since apparently no organisms are associated with the dis-


ease that can be considered the causal factor, and since the disease is brought on by feeding the plants with organic nitrogenous manures in excess, it is to be concluded that the gum formation, by which the disease manifests itself, is induced by chemicals contained in or arising from these manures.
Therefore, the purpose of these experiments is to determine (1) whether any of the organic compounds contained in organic nitrogenous manures or arising from them as a decomposition product can induce gum formation; and if so, (2) whether the types of gum formation produced are the same as those of Dieback.
There is a large number of chemical compounds present in or arising from the decomposition of organic matter in the soil. Doubtless the character of these compounds varies with the conditions under which the decomposition takes place. The selection of a compound for study was determined by the work of Shorey (Shorey-Journ. Agr. Research 1:357-363). He isolated three organic compounds from soils collected about Die-back trees. These were benzoic acid, metaoxytoluic acid and vanillin. The latter was found in such quantities that it could be isolated from the soil in pure form, a result which had not been accomplished before. This chemical was selected for the studies reported herein.
THE ACTION OP VANILLIN ON CITRUS SEEDLINGS
This experiment is one of a series to determine whether gum formation will result from the toxic action of vanillin upon citrus seedlings. It is entirely qualitative.
In Dieback, apparently two types of gum formation occur. The one is that occuring in the cambial tissues which results in the formation of the gum pockets; and the other, that which occurs in the cortical tissues resulting in the formation of the bark excrescences, the stained terminal branches and the marked fruit. In the former, free gum is formed and whole cells are broken down and become a part of the gum mass; in the latter, the gum occurs principally as cell occlusions. The former is developed in young .developing stems; the latter is developed in older tissues that are nearing maturity!
In this experiment, the seeds were planted on a nutrient agar media and allowed to grow about one month. In that time the seeds germinated and the stems made a length growth to where the second pair of leaves were beginning to develop. Judging


C 11V (*,'.*
Fig. 4.Citrus seedlings showing the influence on root development of nutrient media containing vanillin in various concentrations from 39 to 5000 parts per million. The longer roots in the 2500 ppm. media were produced in breaks in the agar media made by drying out. They did not penetrate the media at all.


from the time of development of gum formation in the cortical tissues of Dieback tree3, it was not expected that any gum formation would show in the cortical tissues of these seedlings, but it was thought possible that gum formation might occur in the cambial tissues. The gum might or might not be evident to the naked eye, but it would show in microscopic sections. (Fla. Agr. Exp. Sta. Rep., 1912, p. cv.)
Free hand sections were made of all plants in the experiment, and no evidence of gum formation could be found, altho the development of the plants, particularly those grown in nutrient media containing 5,000 and 2,500 ppm. of vanillin indicated plainly a toxic effect. The results are not conclusive because it is not known that gum formation will occur in tissues of this type at this age. It has not been observed in the field in plants less than one year old. However, neither observation nor experiment has been sufficiently extensive to say definitely that it will not occur in tissues of this type and age.
Plan of the Experiment.The plants were grown under sterile conditions in long homeopathic vials of about 25 cc. capacity. A complete nutrient media containing 2 percent agar and 25 ppm. of nitrogen was used as a growth medium. A low strength of nitrogen was used with the idea that the plant would absorb the vanillin more readily.
The nutrient media was made up in the following proportions :
Magnesium sulphate .................................................. .25 gram
Mono-potassium phosphate .......................................50 gram
Mono-calcium phosphate ...........................................50 gram
There were ten series included in the experiment in which eight different strengths of vanillin, varying from 39 to 5,000 parts per million were used. The media for each series was v made up separately. Equal amounts of the double strength nutrient media and double strength vanillin were mixed, and sufficient agar added to make 2 percent. The lots were heated in the autoclave and funnelled into vials. About 10 cc. was placed in each vial. The vials were then plugged with cotton and sterilized for 15 to 20 minutes at 15 lbs. pressure.
Grapefruit seed fresh from the fruits and soaked two days in water were used for planting. The seed selected were uniform in size. They were sterilized during four hours in a solu-
Potassium sulphate
Sodium nitrate Ferric chloride Distilled water
. .25 gram .15 gram .01 gram 1.00 liter


tion of 14 grams of chloride, of lime in 140 cc. of distilled wate (Wilson, J. K. Am. Journ. Bot. 2:420-427, 1915.) The see were transferred immediately from the solution to the vials b means of a spoon and with the usual care necessary to avoi contamination. Two seeds were planted in each vial. Ten c more vials were included in each series.
The experiment was constituted as follows: Series I Nutrient solution alone.
Series II Nutrient solution plus nitrate of soda to make
100 ppm.of nitrogen. Series III Nutrient solution plus vanillin 5000 ppm. Series IV Nutrient solution plus vanillin 2500 ppm. Series V Nutrient solution plus vanillin 1250 ppm. Series VI Nutrient solution plus vanillin 625 ppm. Series VII Nutrient solution plus vanillin 312 ppm. Series VIII Nutrient solution plus vanillin 156 ppm. Series IX Nutrient solution plus vanillin 78 ppm. Series X Nutrient solution plus vanillin 39 ppm.
Results.The seed were planted on May 31 and the exper ment was closed on July 1. During this time, all of the see had germinated. The stems had attained such lengths thj many of the tips were touching the cotton and in some cas( beginning to force their way out between the cotton and tl wall of the tube. The roots, where the character of the medi permitted, were curling in the bottom of the tube. Many of tr plants had shed their seed leaves. The root tips began to a] pear at the end of two days after planting; at the end of week, practically all seed had germinated. Those that had no did not germinate later.
The first indication of toxic action, was the inability of tr roots to penetrate the media. This occurred in the series whe] concentrations of 156 ppm. and above were used. Later, tl roots in the series of all concentrations up to and including th< of 1,250 ppm. penetrated the media, but made increasingly slo growth from the lower to the higher concentrations.
The roots in all series where vanillin was used, were di; colored from a purplish-brown to a brown color to a short di; tance above where they were in contact with the media. Th color was most pronounced near the surface of the media. A the tips dipped deep into the media, the coloration was lei intense; in some cases the regions back of the tips were almof white.
This coloration was due to injury to the epidermal and tr sub-epidermal cells. In the concentrations from 1,250 ppr upwardthe injury extended much deeper into the tissuei


some cases killing it into the phloem region. With later growth a cork cambium was formed, cutting off the dead tissue which gave the root surface a rough flaky appearance.
A marked discoloration was evident in the xylem region, particularly in the higher concentrations. In the lower, concentrations the sections, made after the experiment was closed, showed discoloration only in that part of the xylem lying adjacent to the pith. The remainder of the xylem was normal in appear-" ance. The xylem discoloration extended only to a short distance into the stem.
Cross-sections made at intervals from the tips of the roots to the tips of the stems of plants in all series failed to show any indication of gum formation. The xylem tissue laid down by the cambium, even beneath the points where the greatest injury had occurred in the cortical region, was complete and without break.
Notes on Plants in Series.Series I.The plants made a normal growth. The roots penetrated the media well, and curled in the bottom of the tube, but they were rather slender. The stems were somewhat slenderparticularly as compared to those in the next series.
Series II.The plants in this series made an excellent growth. The roots and stems were long and strong. These were by far the best plants in the experiment. Since the only difference between this and Series I was the amount of nitrogen contained in the media, it is indicative that 25 ppm. of nitrogen was not sufficient for making the best growth and that 100 ppm. was much nearer the optimum.
Series III and IV.The plants in these series showed the greatest amount of injury from the vanillin. The roots failed to penetrate the media and became very much thickened and knob-like, where the tips were in contact with the media. New tips were put out back of the dead ones, which were in turn killed. The mass had a stubby finger-like appearance.
Marked injury to the cortical tissues was evident. This tissue was later cut off by a cork cambium, giving the surface a rough, flaky appearance. Later in the experiment, where the agar began to break from drying out, fresh root tips were put out that quickly grew the length of the break, but were injured when they came in contact with the media.
The stems made a short but apparently normal growth. Evidently the poison did not affect the top growth directly, as is


the case where a plant is injured by a strong poison such as a soluble salt of heavy metals.
Since the injury to the roots is so marked, and all evidence of direct injury to the tops, such as any spotting or killing of the tissues, is absent, it is indicative that the poison is one that produces only local injury, and that its direct effect is not extensive as is the case of a strong poison such as mercuric chloride.
Series V to X.The plants in these series made a growth somewhat comparable to that of the plants in series I. The tops showed no direct injury. The stems and roots were somewhat shorter in the higher concentrations.
The roots were slow in penetrating the media having, a concentration of 156 ppm. upward. However, finally, all roots penetrated, grew thru the media and curled in the bottom of the tube. The roots in 156, 312 and 625 ppm. vanillin showed more or less surface injury, especially on the large roots. This was much more marked on the plants in the 1250 ppm. vanillin media. The roots in all of the series were discolored where in contact with the media.
Conclusions.No gum was formed in the grapefruit seedlings by the toxic action of vanillin under the conditions of this experiment. However, this does not prove that it may not be formed in the tissues of older plants or under other conditions.
Marked injury to the roots was produced by the vanillin without producing any spotting or killing of the tissues in the stem. This is indicative that vanillin cannot produce injury to the same extent as does mercuric chloride, which can produce widespread injury and gum formation in older citrus plants.
Effect of Vanillin on Citrus Cuttings
The following experiment was carried out to determine whether or not vanillin would induce gum formation in cuttings from citrus trees. The experiment was carried out in a complete nutrient solution containing different concentrates of vanillin. One of the checks consisted of the nutrient solution plus 100 ppm. of copper sulphate. This chemical is known to produce gum formation readily in citrus trees. It was, therefore, presumed that it would do so here, if the conditions of the experiment were right for gum formation.
Fresh cuttings of immature and mature terminal branches were obtained from a rapidly growing nine-year-old pineapple-


orange tree on sour stock. The immature cuttings were angular branches that had not completed their length growth and were in a succulent condition. The mature cuttings were branches that were produced the preceding (spring) flush of growth and were well matured. The stems were more or less rounded.
The branches were cut from the tree and immediately' immersed in water. In the laboratory, they were cut under water before being used in the experiment.
The nutrient solution and the concentrations of vanillin were the same as those used in the experiment with citrus seedlings, which has just been described. (The effect of vanillin upon citrus seedlings). No agar was used nor were the solutions sterilized.
Three hundred cc. Erlenmeyer flasks containing 200 cc. of the solution were used for holding the cuttings. Five flasks were included in a series, and two cuttingsa mature and an immature onewere placed in each flask. The experiment was carried out in a moist glass chamber erected in the laboratory. The experiment consisted of the following series:
Series I Complete nutrient solution.
Series II. Complete nutrient solution plus sufficient nitrate of
soda to make 100 ppm. of nitrogen.
Series III Complete nutrient solution plus copper sulphate 100
ppm.
Series IV Complete nutrient solution plus vanillin 5000 ppm.
Series V Complete nutrient solution plus vanillin 2500 ppm.
Series VI Complete nutrient solution plus vanillin 1250 ppm.
Series VII Complete nutrient solution plus vanillin 625 ppm.
Series' VIII Complete nutrient solution plus vanillin 312 ppm.
Series IX Complete nutrient solution plus vanillin 156 ppm.
Series X Complete nutrient solution plus vanillin 78 ppm.
Series XI Complete nutrient solution plus vanillin 39 ppm.
The experiment was begun June 24, and was closed June 27. In studying the formation of gum in plants in the field by placing chemicals beneath the bark, it was found that it usually required from 36 to 48 hours for the first indication of gum formation to show. (Fla. Agr. Exp. Sta. Rep., 1913, p. xxx.) It was therefore considered that from three to four days should be quite sufficient time for gum development in the cuttings.
Results.The cuttings were without change in gross appearance until the beginning of the third day. No wilting had occurred and the leaves were more or less tinged. On the morning of the third day much wilting and defoliation was evident in all of the cuttings except those in the nutrient solu-


tion without copper or vanillin. No indication of gum formation was evident to the unaided eye.
Cuttings were selected from the series and sections made to note for the presence of gum cycles. None were found.
On the morning of the fourth day practically all of the cuttings in all of the series were defoliated. The succulent cuttings were badly wilted and dying. Cuttings were again selected and sectioned for study. No gum cycles were found.
Since no gum was found in the cuttings of the check series containing copper sulphate, and since the chemical is known to produce gum formation readily, it is to be concluded, either that copper sulphate at this concentration cannot induce gum formation, or that gum formation is impossible in the cuttings. Gum formation is known to be a function of active, growing cells. The more rapid the growth the greater is the gum formation. It is possible that the lack of gum formation in the cuttings is due to absence of growth.
Injury to Citrus Trees by Ground Limestone
The attention of the Experiment Station has been called to a number of groves in which the use of ground limestone has apparently led to injury. This injury showed itself by a marked frenched or chlorotic condition of the foliage. With late development there was lack of growth, much defoliation, a development of multiple buds, and a hard dry appearance of the bark, giving the tree a general starved appearance. The roots showed evidence of injury by the presence of very few live feeding tips. Apparently the regions back of the fibrous roots were in a healthy, normal condition.
That ground limestone should be suspected of inducing injury under any condition has occasioned much surprise among the growers. The general impression has been that it was a natural product which under all conditions was not only entirely harmless but was highly beneficial to plant growth. From grove observations and field experiments there is strong evidence indicating that under certain limited conditions ground limestone may induce injury to young citrus trees in Florida.
That injury may occur to plants from the presence of excessive calcium carbonate (lime) in the soil has long been known. Certain plants are much more susceptible to such injury than others. Frear, in a review of the literature on the liming of soils (Sour Soils and Liming, Dept. Agr. Penn. Bui.


261, p. 45), calls attention to a number of plant diseases caused by an excess of calcium carbonate in the soil.
" Grapes growing upon certain limestone soils in Prance often suffer from chlorosis, a white spotting of the leaf, associated with great depression in the vigor of the plant.
" Other plants also than the grape became chlorotic under like influences. G. Riviere and G. Bailhache observed that excess of calcium carbonate in soil is attended by chlorosis of pears grown upon quince stocks, and that a chlorotic appearance occurred when no more than 4 percent of the carbonate was present; and that the attack was conspicuous with 17 percent of the carbonate, and with 28< percent death ensued.
" P. Maze, Ruot and De Moigne observed that the addition of 0.2 percent of calcium carbonate to a water culture in which Vicia narbonnensis was flourishing, causes chlorosis, also that the white lupine and the vetch became chlorotic in the presence of an excess of calcium carbonate to which corn was resistant; but Maze caused chlorosis of corn by keeping the excess of lime carbonate, but diminishing the iron and sulphuric acid in the nutrient solution."
Gile (Porto Rican Exp. Sta. Bui. 11) reported the failure of pineapples with the appearance of chlorosis (frenching) on certain areas of the Island where there was an excessive amount of calcium carbonate in the soil. He made an extensive study of the problem in the course of which numerous experiments were carried out and many analyses made. He found that for ordinary sandy soils, about 2 percent of calcium carbonate renders them unsuitable for pineapples. Smaller amounts than this did not appear to be injurious. On the other hand, soils containing as high as 40 percent of calcium carbonate but composed principally of organic matter produced vigorous plants. He was able to produce the trouble readily on sandy soil by the addition of lime in quantity to the soil. He concluded that lime reduced the availability of the iron in the soil, so that the plant absorbed an excessive amount of calcium and an insufficient amount of iron. This reduced the ability of the plant to form chlorophyll, which in turn led to further injury and finally to the death of the plant.
An interesting point in the development of the trouble in the field and in the greenhouse was that the plants, after being set out, grew normally thru a period of several months before they developed the diseased condition.
" The root system of the chlorotic plants showed no evidence of disease. The roots differed from those of normal plants in being somewhat larger and not so thick; they were more like those of plants suffering from starvation. The plants, however, that suffered from the chlorosis for some time had many dead roots, but the functioning roots appeared to be perfectly healthy and an examination by the pathologist failed to show any bacterial or fungus trouble."


FlG. 5.Citrus tree around which ground limestone was used.
DREW GROVE
The first case of apparent injury from ground limestone to come to the attention of the Experiment Station was that in the grove of W. L. Drew of Winter Haven. In September, 1913, he addressed the Director of the Experiment Station as follows:
" I have had an unexpected experience in causing frenching by the use of
ground limestone......I have at Winter Haven, my own grove of 25% acres,
and joining it I have charge of my brother's grove of 16% acres. Twenty-eight rows of trees in this latter grove are Duncan grapefruit. Each row contains nineteen trees. Fourteen rows are on rough lemon roots and fourteen on sour orange roots. These trees were set in December, 1910. The trees of the two adjoining rows, the last row on rough lemon and the first row on sour orange, were set in soil with which there had been mixed a liberal quantity of ground limestone. No lime of any kind has, up to the present time, been used in any other portion of the grove. The trees where the limestone was used showed no difference in growth or appearance from the other trees during the first summerthe summer of 1911.
" On May 10, 1912, we scattered a liberal quantity of the ground limestone around the trees of these two rows and all over the middle between the two rows. In the summer of 1912 we failed to observe any effects of the ground limestone in the trees that were on rough lemon roots. The trees of the


row on sour orange seemed to be growing a little faster and looked a little thriftier than the remainder of the trees on that root. I did not see the trees from September, 1912, to July, 1913. At this time both of these treated rows showed a large amount of trenching in great contrast with the trees on either side that showed almost none at all. I took three men at different times out to see the grove and telling them of this experience with ground limestone asked them to point out the rows. This each one did, without hesitation, long before he had reached them.
" The grove is situated on good average high pineland of the Winter-haven section. All of the trees have had the same care and fertilizer from the first. As there is no difference in the character of the land where these two rows are, it is evident that the limestone has caused the trenching. It may be that where limestone is used, a fertilizer of a different character should be used. 1 can hardly believe that the lime itself has been injurious and so I suspect it to be the lime and the fertilizer combined.
".....Beggarweed is the cover crop in this grove. I might add as a
result of this experiment, and another previously made, that it is clear that on this land, where no fertilizer was applied, beggarweed is not benefited by an application of ground limestone. I hesitate to state that it has been injured but such seems to be the fact. There are spots all over both of these groves where the beggarweed frenches and does not grow well, at least in the absence of fertilizer, and this condition seems to be more pronounced where ground limestone has been applied."
Fig. 6.Citrus tree around which ground limestone was not used. Tree is of same age, same variety, on same stock and in adjoining row to one shown in fig. 5.


Fig. 7.View in citrus grove of middle over which ground limestone has been spread. Trees to left on sour stock. Trees to right on rough lemon stock. Note absence of cover crop.
Subsequent History of Grove.Since September, 1918, when this letter was written, the trees in the two rows have made slow growth. Their appearance has varied with the season. At all seasons the marked trenched condition has prevailed more or less. In the winter of 1915, they had a general starved appearance. The type of growth which had developed was quite different from that of the trees in the adjoining rows. Instead of general growth all over the tree, it was somewhat confined to rather strong shoots toward the center of the tree. These had made more or less of a straight lengthy growth, giving the tree a rather upright type of growth instead of a compact spreading type that characterized the trees in the other rows. A general lack of foliage gave the trees a very open appearance. The trenching and defoliation occurred more toward the tips of the branches. The tip leaves were often completely yellow. The leaves toward the base of the branches were more plentiful and had a somewhat normal size and color. Multiple buds were more or less plentiful on many of the short terminal branches. These branches were frequently completely defoliated. The bark of the large branches and of the small ones a year or more old had a rather hard dry look. The fibrous roots were brown and dead. Very few live ones could be found. The main roots appear to be alive and normal.
The difference between the cover crop between the two rows and in the remainder of the grove was very noticeable. Be-


Fig. 8.View in citrus grove of middle adjoining one shown in fig. 7. No ground limestone has been applied. The trees of both rows are on sour stock. The row on the right is the same as row on the left in fig. 7.
tween the two rows, it had evidently been very sparse, whereas, in the remainder of the grove it was more or less plentiful. In the former the plants had come up, made a little growth, turned yellow and died; in the latter they had made complete development. Cowpeas had been planted between the two rows but had made very little growth.
In April, 1916, the trees had put out some new growth that gave them an improved appearance. The old foliage and some of the new showed trenching. The abnormal condition still existed in the soil. At the end of a period of ten days during which no cultivation had been done on account of a rain, the volunteer cover crop seedlings were coming through the soil very plentifully in the grove; very few were evident in the area between the affected trees, except at one end where some stable manure had been applied during the spring of 1915.
Fertilizer Treatment.The fertilizer given the two rows was the same as that given the remainder of the grove up to August, 1913. It was as follows:
March, 1912-......._________.....______4-6-6 from sulphate of ammonia, sulphate of
potash, dissolved bone black, blood and bone tankage, about 1 lb. per tree.
June, 1912.............-........ ..........4-6-6 from same sources, about 1 lb. per tree.
August, 1912............................4-6-12 from sulphate of ammonia, sulphate of
potash, and acid phosphate, a little over 1 lb. per tree.
February, 1913........................5-6-6 from sulphite of ammonia, sulphate of
potash, and dissolved bone black, a little over 2 lbs. per tree.


June, 1913.................................5-6-5 from nitrate of soda, sulphate of ammonia, tobacco stems, steamed bone flour, dissolved bone black, and sulphate of potash, about 2% lbs. per tree.
August, 1913 (except trees
1 to 9 in both rows)...........5-6-5 from the same sources, 2 lbs. plus per
tree.
From August, 1913, to January, 1915, the fertilizers applied were as follows:
Cctober 16, 1913......................Trees 1 to 9, both rows (not fertilized August,
1913), 3% lbs. each of Painter's Dieback Fertilizer of formula 8 percent phosphoric acid .and 13 percent potash.
December 13, 1913..................All trees, 2 lbs. per tree of formula 3-6-13
from sulphate ammonia, acid phosphate, and double manure salts.
March 26, 1914........................All trees, 2% lbs. per tree of formula 4-6-6
from nitrate of soda, sulphate ammonia, acid phosphate, ground steamed bone, and sulphate of potash.
June 18, 1914...........................All trees, 4 lbs. per tree of formula 4.25-6-12
from nitrate soda, sulphate ammonia, ground steamed bone, low grade sulphate of potash and floats.
In January, 1915, the two rows were divided into plots and fertilized according to a plan outlined by a fertilizer representative. The treatment was as follows:
January 2, 1915.......................Trees 1 to 4, both rows, 6 lbs. per tree of formula 3-6-10 from nitrate soda, sulphate ammonia, dried blood, acid phosphate and sulphate of potash.
Trees 5 to 7, both rows, 6 lbs. per tree of a fruit and vine brand.
Trees 8 to 10, both rows, 9% lbs. per tree of the mixture: 4-12-6 from sulphate ammonia, dissolved bone black and sulphate
potash ................................................27 lbs.
Copperas............................................ 3 lbs.
Goat manure......................................30 lbs.
Trees 11 to 13, both rows, 9% lbs. per tree of the mixture: 3-10-6 frpm sulphate ammonia, nitrate soda, dried blood, acid
phosphate and sulphate potash......37 lbs.
Copperas............................................ 3 lbs.
Trees 14 to 16, both rows, 13% lbs. per tree of
the mixture: Hardwood ashes......25 lbs.
Copperas ............................................ 4 lbs.
Steamed bone....................................25 lbs.
Goat manure......................................25 lbs.
Nitrate soda...................................... 3 lbs.
Trees 17 to 19, both rows, 11 lbs. per tree of the mixture: Steamed bone....30 lbs.
Copperas ............................................ 3 lbs.
Goat manure......................................30 lbs.
Nitrate soda...................................... 3 lbs.
In March, 1915, only a part of the trees were fertilized. The
plan as outlined in January was discontinued on account of the


unfortunate death of the fertilizer company's representative. The fertilizer applied in March was:
March 11, 1915........................Trees 1 to 4, both rows, 6 lbs. per tree of formula 3-6-3 from sulphate ammonia, nitrate soda, acid phosphate, goat manure, tobacco stems and potash.
Trees 5 to 7, both rows, 6 lbs. per tree, a fruit and vine brand.
Trees 8 to 19, both rows, not fertilized at this time. Expected to continue experiments but stopped on account of death of representative.
About this time a light application of stable manure was spread over the area between the first two trees of both rows. A cover crop developed quickly over the area but the application was apparently without benefit to the trees.
From June, 1915, to April, 1916, all of the trees were fertilized alike, as follows:
June 23, 1915............................All trees, 6 lbs. per tree of Painter's ammoni-
ated Dieback fertilizer.
December 31, 1915....................All trees, 7 lbs. per tree of formula 3-8-2 from
sulphate ammonia, acid phosphate, ground tobacco stems and goat manure.
February 10, 1916....................All trees; 4 lbs. per tree of formula 4-8-0 from
nitrate soda, sulphate ammonia, and acid phosphate.
April 15, 1916..........................All trees, 4 lbs. per tree of formula 4-8-0 from
sulphate ammonia and acid phosphate.
Discussion.Since, up to the time that the injury was first noticed, the only difference in treatment between the two rows and the remainder of the grove was the ground limestone applied, and since soil conditions are practically the same where they were planted as in the remainder of the grove, it seems quit^e evident that the ground limestone has been the direct or indirect cause of the injury to the trees. How the limestone has induced the injury is a matter of conjecture. The wide use of ground limestone in the citrus groves of Florida without any apparent injury and with apparent benefit indicates that the injury can occur only under very special conditions. The conditions prevalent in this grove must be an indication of the conditions necessary for the development of the trouble. A cursory review of these showed that the tendency of the soil to dryness and the lack of humus were probably the chief abnormal conditions present. The grove practices are such that the humus supply would not be conserved or increased. The intimate mixture of the ground limestone with the soil in the holes where the trees were planted is probably another factor in the development of the injury.


The greatly increased growth of the trees on the sour stock receiving the ground limestone over those on the same stock not receiving it indicates that the first effect of the limestone was to bring about a soil condition that was stimulating to growth. This was followed by a condition that was conducive to injury not only to the trees but also to the cover crop.
The application of the manure in 1915, enabling the cover crop to grow readily, is indicative that the injury of the trees may be due to a lack of bacteria in the soil.
The application of the organic sources, dried blood and goat manure, in connection with the plot treatments in January, 1915, did not bring about any marked increase of the cover crop. Therefore it is probable that the stable manure was valuable more on account of the bacteria that it added to the soil than on account of the organic matter added.
This same appearance of the trees and lack of growth of the cover crop has been observed in other groves where limestone was not used but where the soil had apparently been injured by excessive cultivation. Such injury has not been observed excepting in groyes planted on dry sandy lands lacking in humus. Where such injury has occurred the limiting of cultivation to the spring season, the adoption of grove practices that build up the soil, and severe pruning have brought about a recovery of the trees.
OTHER GROVES
In a number of other groves where ground limestone has been used the same type of injury to the trees and to the cover crops has developed. All of these groves were planted on dry, sandy lands lacking in humus. None of the trees was more than seven to ten years old. Injury to the trees followed a period of normal growth. The first indication of injury was trenching. This was followed by the development of a general starved appearance in spite of the fact that the trees were well fed. However, in these groves it was very difficult to trace the injury to the ground limestone because it had been applied uniformly over the groves. No part was left without it. If ground limestone can cause injury to citrus trees it probably has done so in numerous cases in the past, but the connection has been overlooked thru attributing the injury to other causes or thru a lack of checks for comparison.


EXPERIMENTAL GROVE, TAVARES
The Experiment Station has a fertilizer experiment at Ta-vares, Florida, in cooperation with Mr. G. M. Wakelin (Fla. Agr. Exp. Sta. Rep., 1909, p. xxvii). There are 47 plots receiving fertilizer treatment and one plot without fertilizer. Of these there are three that have received ground limestone in addition to the fertilizer. The limestone was applied first soon, after the trees were set out in January, 1909, and at irregular intervals since. Each application consisted of 10 pounds per tree. During the first few years after the experiment was started trenching was general thru the grove on account of the presence of Dieback in the trees. During the year 1915 the trees had mostly recovered from the Dieback conditions and the plots showing trenching stood out in more or less marked contrast to the remainder of the plots.
Five plots showed a severe attack of trenching (Fla. Agr. Exp. Sta. Rep., 1915', p. c). The fertilizer treatments given and the order of severity of the attack is as follows:
Plot 21................5-C-6 formula from cottonseed meal, acid phosphate,
sulphate of potash with ground limestone.
Plot 11................5-6-6 formula from sulphate of ammonia, acid phosphate, and sulphate of potash with ground limestone.
Plot 30................5-6-6 formula from nitrate soda, acid phosphate, and
hardwood ashes.
Plot 28..............5-12-6 formula from nitrate soda, Thomas' slag, sulphate
of potash
Plot 39................5-6-6 formula from sulphate of ammonia, acid phosphate, and sulphate of potash with ground lims-stone.
Plot 21, where the ammonia of the fertilizer applied was derived from cottonseed meal and ground limestone was .used as a soil addition, shows by far the greatest amount of trenching. During the winter of 1915 the foliage on these trees became quite yellow and there was much defoliation.
None of the trees in the trenched plots was as markedly injured as the trees in the Drew grove. However, here no ground limestone was mixed in the holes where the trees were planted.
In the summer of 1916 the trees through the whole grove had put on a good growth and all except the trees in the trenched plots showed a more or less normal color. Frenching was still persistent in plots 21, 11, 28, and 39. Plot 30 had recovered and showed very little yellowing. But plot 20, which received the same fertilizer treatment (5-6-6 from cottonseed meal, acid


phosphate and sulphate of potash) as plot 21, but without the ground limestone, now showed a marked case of trenching.
It is thus seen that all of the ground limestone plots in this grove, in addition to some others, showed injury.
POT EXPERIMENTS WITH GROUND LIMESTONE
As a part of other experiments in the greenhouse, the following pot experiment was carried out, using ground limestone in pure sandy soil and without fertilizer. The purpose was to determine the effect of the limestone upon the plant in the absence of other materials (such as fertilizer) which might interfere with its action. Under the conditions of the experiment it was to be expected that the plants would show the effect of starvation as the soil used was a pure sand almost without organic matter and therefore lacking in the food elements.
Grapefruit seed were planted-in the pots on February 8, 1915, and allowed to grow until about June 22. At this time, the plants were free from the seed and entirely dependent upon the sand for food. Five pots were included in a series and five seed were planted in a pot. The sand used was a coarse sand from the shores of Lake Weir in Marion county. The pots were six-inch pots, the walls of which had been soaked in paraffin. The experiment was carried out on the east bench of the greenhouse under uniform light conditions and under as nearly uniform moisture conditions as the average greenhouse watering will allow.
The series and their treatment are as follows:
Series I ................Ground limestone....................48 grams
Series II ................Ground limestone....................32 grams
. Series NT................Ground limestone....................24 grams
Series IV ................Ground limestone....................16 grams
Series V ................Ground limestone....................12 grams
Series VI ................Ground limestone.................... 8 grams
Series VII ................Ground limestone.................... 4 grams
Series VIII................Ground limestone.................... 2 grams
Series IX ................Ground limestone.................... 0 grams
The ground limestone was well mixed with the sand before placing it in the pot.
Results.Table 14 shows the results of measurements made upon the plants when the experiment was closed late in June, 1915. From these, it is evident that the plants of all series excepting I and II made a growth that was no better than that of series IX which received no limestone. The plants of series I and II made on the average 7 and 11 percent greater growth


Fig. 9.Pot experiments with ground limestone. No. I, grown in sand to which 48 grams of ground limestone had been added. No. IX, grown in sand without the limestone.
respectively than the plants of series IX without limestone. This increase is comparatively small.
The most marked difference between the plants receiving ground limestone and those not receiving it was in the leaf color and in the root development. The plants of Series I to VI inclusive showed marked trenching with a yellowish-green back-


ground. There was very little variation among the different series. The plants of series VII and VIII showed only traces ol trenching. The plants of series IX were entirely free frorr f renching but had the yellowish-green color indicating at leasl nitrogen hunger.
There was an appreciable difference in root development between the plants receiving ground limestone and those not receiving it. This difference was noticeable even where only twc grams of limestone were used per pot, but was more pronounced where the larger amounts were used. The roots in all cases were slender but were longer and more profusely branched ir the limestone series. All roots, with the limestone as well as without the limestone, appeared normal. No dying of the tops was evident.
TABLE 14
Pot Experiments with Citrus Seedlings
Series No. Stem Length Stem Diam. Leaf Length Leaf Breadth Fresh Weight Dry Weight Av.
A B A B A B A B A B A B
I .................... 58.3 124 2.3 105 30.9 101 15.1 94 1.27 122 .41 121 Ill
II .................. 54.1 114 2.3 105 30.5 100 15.8 99 1.17 113 .38 112 107
Ill .................. 54.5 115 2.3 105 29.3 96 15.1 94 .98- 94 .32 94 100
IV ............ 49.8 106 2.2 100 29.4 96 15.4 96 .93 89 .30 88 96
V ................. 50.4- 107 2.2 100 29.3 96 15.0 94 1.00 96 .32 94 98
VI ................. 52.9 112 2.2 100 31.0 102 15.1 94 1.10 106 .34 100 102
VII ...... 47.5 101 2.2 100 29.9 98 15.3 96 1.02 98 .33 -97 98
VIII .............. 49.7 105 2.2 100 28.8 94 14.7 92 1.04 100 .32 94 97
IX.................. 47.2 100 2.2 100 30.5 100 16.0 100 1.04 100 .34 100 100
A.Average measurements in millimeters.
B.Relative measurements (check series, 100).
General Conclusions.It seems quite evident that ground limestone can, under limited conditions, induce injury to citrus trees, and that this injury will show itself by a trenching (a form of chlorosis) of the foliage of the trees.
How the ground limestone can induce this injury' is still a matter of conjecture.
Respectfully,
B. F. Floyd, Plant Physiologist.


REPORT OF THE ENTOMOLOGIST
P. H. Rolfs, Director.
Sir : I submit herewith my annual report for the fiscal year ending June 30, 1916.
Velvet Bean Caterpillar
(Anticarsica gemmatilis)
The study of this pest was continued by making further investigations of its migrations, natural enemies, and especially the moths' preferences among the different species and varieties of Stizolobium. The results of this work, as well as that of previous years, have been collected into a bulletin, Life History of the Velvet Bean Caterpillar," which is now in manuscript. A more practical dust for the control of this insect was developed. This has been included in Bulletin 130 which has been published.
The attempt to establish Calosoma sycophanta was not successful. The beetles remained active until the rainy season set in. They then began to appear above ground less frequently and to refuse food. They finally passed into complete aestivation; most of them died, and the remainder did not become active again until the following spring. Not one egg was observed. Apparently the insect is not adapted to the climatic conditions of Florida.
Florida Flower Thrips
Most of the time spent in studying this insect was given to (1) its seasonal history, especially its manner of spending the winter, and the reason for its greater abundance in dry weather, and (2) the extent of its damage to citrus.
HIBERNATION
In addition to a careful watch of the insect in the field, individuals were caught and placed in test tubes closed with cotton plugs. These test tubes were kept constently supplied with fresh food (rose petals) and were placed in an open-air insect-ary where they were exposed to the same temperature as in the open fields. They were, of course, protected from heavy rains. The test tubes were placed on the north side of breeding cages made of wire netting. Here they were protected from the direct rays of the sun, which would have caused a marked rise in temperature during the middle of the day, yet they were well


lighted. Most of the thrips placed in these tubes died within a few days after their introduction but many lived for several weeks and one individual lived for 59 days. This did not represent the insect's maximum age as it was doubtless several days old when caught.
Observations during the winter of 1915-1916 confirmed those of the previous seasons (see Fla. Agr. Exp. Sta. Rep., 1915, p. lxvi) that the Florida flower thrips does not breed during the cooler weather of winter. But on January 5, after a week of warm weather, a few young were found in one of the test tubes in the open-air insectary. On the same date, on some 50 roses examined on the Station grounds, three larvae were found.
During the winter, including the coldest days, thrips were always found in the rose blossoms even when the latter were badly frosted. During such weather they were inactive but would move if disturbed.
Our studies have thus far established that the Florida flower thrips spend the winter as adults in blossoms, but there may be some breeding during a warm period in any month of the year. There are no indications that they ever enter the ground or seek other shelter than the depths of the flowers. They are capable of living as adults for at least eight weeks during the winter. This length of time is sufficient to tide them over the non-reproductive period as breeding usually continues until some time in December and begins in late February or March.
HEAVY RAINS VERY DESTRUCTIVE
Ever since the writer has been in Florida, he has noticed that thrips are much more abundant during and immediately following a period of drouth. During the last year closer observations have been made to determine the factor responsible for their disappearance. As many insects in Florida are controlled during the hot moist rainy season by entomogenous fungi, an especial search was made for such fungi parasitizing thrips. Al-tho Microcera-like fungi were occasionally found growing on dead thrips, there is no evidence that entomogenous fungi are an important factor in their control. Nor was lack of food the factor, as thrips would often be greatly reduced in numbers when there was no corresponding reduction in the number of available blossoms. On the other hand, after hard, dashing rains or prolonged rains not especially violent, there was always a great reduction in the numbers of thrips. For instance, thrips


were abundant on roses and other blossoms on the Station grounds during the early part of December, 1915; but from December 17 to 20, Gainesville experienced a heavy rain, 4.26 inches falling. On fifty roses examined on December 22, no thrips were found. Similar observations tho less striking in results, were made during the summer of 1915. We were able to get equally striking results with a garden hose when the flowers were given a thoro drenching. The insects were washed to the ground and killed. It is evident that prolonged or dashing rains are very destructive to thrips and are the chief natural factor in keeping down their numbers.
THRIPS CTN CITRUS
In the last Annual Report, p. lxviii, we recorded some spraying experiments carried on in the Scott grove at Winter Haven. The grove was visited again on October 1, 1915, and a count made of the fruit on the sprayed and unsprayed rows. It did not differ materially from that made the preceding June as recorded in the last Annual Report, but we were able to obtain better data as to the amount of fruit showing thrips marks." In getting the following percentages we counted only those fruits which showed a sufficiently large area marked to be readily noticeable on the oranges; in other words, those fruits only which in the hands of a careful grader would have their grade lowered on account of the markings. Our check rows showed 32 percent of such fruit; sprayed rows only 13 percent.
During the spring of 1916, similar experiments were undertaken on Pine Island, at Leesburg and at Stanton. The season was unfavorable for this work, due to the irregularity of the bloom. Only a few trees in any one grove were in full bloom at any one time, so that in order to do satisfactory work it would have been necessary to spray once a week over a period of nearly two months. Only one grower was willing to do this. All of the bloom on the Station grounds and most of that in the Gainesville section was killed by a freeze in February, so that it was impossible to carry on experiments at Gainesville and it was necessary to depend upon cooperative experiments. In the Tillson grove at Leesburg and in the McKenney grove at Stanton several acres were sprayed. Only a few of the trees were in full bloom. These were carefully marked. On June 28 and 29 these groves were again visited. Because of the small amount and scattered nature of the bloom at the time the trees


were sprayed, we could secure no reliable data on the comparative amount of fruit on the sprayed and check trees. In regard to the amount of scarred fruit more definite data could be secured. In the grapefruit grove at Stanton, 23 percent of the fruit was sufficiently scarred by thrips to lower the grade in the hands of a careful grader; the percentage on the sprayed portion was only 9. An adjoining grove of equal age and also un-sprayed showed 16.5 percent of scarred fruit. Four percent would probably develop into culls-only.
In the grove at Leesburg, the unsprayed orange trees showed 6.3 percent of scarred fruit. About half of this was badly marked. The sprayed trees had only 2.7 percent. Some trees which were just out of bloom when sprayed showed 9 percent marked fruit.
Altho these results from spraying for thrips are not as striking as the results from spraying for whitefly and purple scale, they undoubtedly pay one well for spraying even when the bloom is unusually irregular and scattering. We estimated that spraying of 300 trees would result in a saving of at least $15 at a cost not to exceed $6.
THRIPS ON STRAWBERRIES
On April 1, 1916, the entomologist was called to Waldo to investigate an outbreak of thrips on strawberries. The infestation was found to be heavy, as many as fifty adults and larvae being found in a single bloom. These heavily infested blooms never set fruit but withered and dried up. Others less severely injured produced deformed, worthless fruits. The production of the field was being seriously curtailed.
Part of the field was sprayed with a home-made tobacco decoction, made by soaking tobacco stems and refuse over night in enough water to cover them. Three gallons of this solution and a pound of soap were used to each 15 gallons of water. This killed all of the thrips reached. As there was considerable red spider in the other part of the field, the following formula was recommended:
Home-made tobacco decoction............................... .....................10 gal.
Commercial lime-sulphur.................................................................. 1 gal.
Water ................................................................................................39 gal.
The red spiders were causing much of the damage attributed to thrips by the growers, such as the production of small, hard brown berries. However, most of the blasted blossoms and the


deformed fruit were caused by thrips. The spraying was entirely successful in controlling the insect.
the florida flower thrips attacks camphor
In April, 1916, Dr. E. W. Berger, Entomologist to the Plant Board, called the attention of the writer to some camphor trees in his yard which were being attacked by thrips. Investigation showed the insect to be the Florida flower thrips and not the Camphor thrips, altho the character of the damage to the unfolding buds of the camphor was very similar to that caused by the camphor thrips (see Fla. Agr. Exp. Sta. Rep., 1913, p. Ixvi). This injury is also very similar to that inflicted on unfolding buds of pears (see Fla. Agr. Exp. Sta. Rep., 1915, p. lxvii). This discovery will render it necessary to use caution in concluding that the camphor thrips is present in any property on the evidence of the lesions in the developing buds alone. On the trees attacked by the flower thrips there were, however, none of the bark lesions so characteristic of the work of the camphor thrips. (loc. cit. p. lxvii and lxvii).
. Combating Nematodes by the Use op Calcium Cyanamide
In the fall of 1914 the attention of the entomologist was called to the toxic properties of the commercial compound called Cyanamid which is a mixture of calcium cyanamide, lime, charcoal, and other compounds in less amounts. The suggestion was made that it be tried out as a possible spray to control insects. It seemed that there could be little use as a spray for such a soluble and toxic compound which would probably burn the plants to which it should be applied. Upon further reflection it seemed possible that the compound might be of value in killing out soil pests if applied before the crop was planted. The nematode (Heterodera radiciola) seemed to be the most suitable organism for a trial, as infested soil could easily be found at any season.
Accordingly, on November 30, 1914, six small plots, each containing three square yards were treated with cyanamid at rates varying from 3 tons to 200 pounds per acre. The cyanamid was applied as a top dressing and hoed in. Four similar plots were used as checks. These were situated on land known to be heavily infested. On December 4, radishes were planted on these plots, but a very poor stand was obtained and the plots were replanted on December 13. On March 18 and,April 20,


Plot Number .......................... 1 2 3 j 4 5 6 7 CO 9 10
Dose, pounds per acre............ 6000 0 3000 0 1600 800 400 0 200 0
Percentage of plants infested 0 33 0: 25 1 24 5 50 8 670 33
Weight of radishes in grams 240 260 475i335 1 780 1015 525 230 535
cyanamid on radishes
Cyanamid, being a strong nitrogenous fertilizer, analyzing between 20 and 24 percent ammonia, a larger yield on treated plots was to be expected. The increased yield on the treated plots is due as much to the fertilizing effect of the cyanamid as to the vermicidal effect. No other fertilizer was used on any of the plots. This experiment seemed to indicate that:
(1) Cyanamid used at the rate of 1600 pounds or more per acre markedly reduced the number of nematodes present; and
(2) If used too strong or applied too near the time of planting, it inhibits growth or entirely kills the plants.
Altho it would greatly increase the cost of application, it seemed that the material should penetrate the soil better if applied in solution. Accordingly a series of plots was laid out but this time the material was dissolved in water* which was poured on the surface except on plot F where it was applied dry and hoed in as in the first series of plots, and then thoroly wet down. These plots were treated on December 5 and planted on December 13. The results are shown in table 16.
TABLE 16 Effect of Cyanimid on Radishes
Plot.................................... a b C d e f Check
Dose in pounds per acre 260 540 1700 3400 5100 5100 0
Percentage infested ........ 50 60 6 0 0 0 94
Deleterious effect on
erable dwarfed
growth ............................ None Nonei None 1 Trace Consid- Plants
Comparing these two tables we find that, contrary to expectations, both absolutely and as compared with the amount in the
*When cyanamid ", the trade name for the impure mixture of calcium cyanamide, is placed in water, only the calcium cyanamide and some of the lime dissolves. There is left a black residue consisting largely of carbon.
the radishes were gathered. The results of this test are tabulated below.
TABLE 15
Effect of Cyanamid on Nematodes in Radish Bed


check plots, the solutions were not as effective as the dry material thoroly mixed with the dry soil and then saturated with water. All later experiments tend to substantiate this view.
These preliminary tests were so encouraging that during the spring of 1915 more extensive tests were undertaken and with the beginning of the fiscal year the subject was included in the project. ~
TESTING EFFECT OF CYANIMID ON COWPEAS
In March, 1915, we started experiments with cowpeas on plots containing a hundredth of an acre each. The large size of these plots was intended to reduce the danger of the results being obscured by the migration of the worms from the sides. To prevent the nematodes being washed over the plots from the surrounding soil, the plots were ridged so that they were slightly higher in the middle. The cyanamid was applied as a top dressing and worked in with a disk harrow. The dose varied from 300 pounds to a ton per acre.
Cowpeas were planted three weeks after the application of the cyanamid. They did well until dry weather set in when all of those on the plots that had received 600 pounds or more per acre showed some burning. On those plots that had received 1400 pounds or more per acre, the cowpeas were not as good as on the checks. On those plots that had received 1500 pounds or more per acre there were at first a few knots on roots that did not extend below a depth of six inches, while on the checks the roots were knotted to the very crown. Three months later the nematodes had worked upward so that on the treated plots also knots began to appear near the surface. Evidently we had failed to get the material down to a sufficient depth. However, the plots that had received but 300 pounds per acre showed fewer knots than the checks. The results of this test are shown in table 17.
These plots were treated on March 5 and Whippoorwill cowpeas planted on March 27. They were broadcasted and raked in. Checks were placed parallel to these plots so there was a check for each plot.
On the plot receiving 2000 pounds per acre there was not over 25 percent of the amount of grass and weeds as on the checks. There was practically no crab grass or Oenothera, both of which were abundant on the checks. But the seed of coffee-weed and beggarweed mostly survived the treatment.


Effect of Cyanamid on Cowpeas and Nematodes
Plot | Dose I per acre j in lbs. Appearance of the cowpeas Amount of Root-knot, July 12
May 21 May 29 1 June 14
1 300 Deeper color Some slight Much better Much less than
than check burning than check check
2 400 Better than Some burning Better than Less than 1
CO 500 1 Better than Burned but 1 Better than Very little
2 2 above depth of
not seriously 6 in.
4 600 Better than More burning Better than As 3
3 not serious 3
5 800 Better than Burned con- Better than As 3
4 siderably 4
6 1000 Better than Burned more Better than As 3
5 than 5 5
7 1200 Nearly as Burned ser- Better than None above
good as 8 iously 6 6 in.
X 1400 Best looking Burned, but Again best As 7
plot still good looking plot
9 1600 Dwarfed and Badly burned Not as good As 7
burned as com- as 8
pared with 8 Badly burned As 7
10 2000 Better than Badly burned but better
check than check
EXPERIMENTS WITH TOMATOES
On April 13, four plots, each 28 by 40 ft., were treated with cyanamid, 80, 70, 60, and 50 pounds respectively, being used. This corresponds approximately to doses of 3000, 2600, 2200, and 1850 pounds per acre. A like plot was left for a check. Here also the cyanamid was broadcasted and harrowed in. Tomato plants were set out April 22.
On all of the treated plots the tomatoes were so badly burned as to be worthless. This burning was not noticeable until a week or more after the tomatoes had been set in the treated ground. On the check plot a small crop of tomatoes was harvested in spite of the nematodes.
These plots were replanted to a second crop of tomatoes sometime in August. This time the reverse was noted. The tomatoes did nothing on the check plot while a fair crop was harvested from the treated plots. There were some nematodes on all the plots.
EFFECT OF CYANIMID ON PEACH TREES
On April 9, 1915, we treated five peach trees with a dose of 6, 4, 3, 2, 1 pounds respectively. The material was scattered
TABLE 17


on the ground over a radius of six feet about the trunk of the tree, and thoroly worked in with a hoe to a depth of two inches.
Two weeks later there were noticeable some wilted twigs on the treated trees, but this condition was only temporary. Some weeks later the trees had a greener and more healthy look than the remainder of the orchard. This was probably due mostly, if not entirely, to the fertilizing effect of the material. But the cyanimid did not, as was expected, kill the trees, due undoubtedly to the fact that it did not get down to the main roots in the form of cyanamide, but had gone to urea and nitrates before reaching the roots.
From these experiments we seemed justified in concluding:
1. That cyanamid applied to the soil greatly reduces the number of nematodes present.
2. That it does not penetrate the soil readily. It is stated by agricultural chemists to be quickly absorbed by the colloids of the soil and then changes to urea and finally nitrates, but that if heavy doses are used a compound (dicyanamid) is formed.
The urea and the nitrates resulting from its decomposition will dissolve in the soil water and penetrate readily so that the fertilizer effects are marked, even when applied as a top dressing, but the vermicidal effects are not. It will therefore be necessary to mix the material with the soil thoroly.
3. That if sufficient time does not elapse between the application of the material and the planting of the seeds or transplanting of the plants, severe damage will result. Furthermore, that there is a great difference in susceptibility to damage among plants, tomatoes being very sensitive, and radishes very resistant.
The problem as it appeared at the beginning of the year was to determine:
(1) The minimum dose of cyanamid necessary to exterminate the nematodes; or, if complete extermination appears too costly or impracticable, the dose which will reduce their numbers to such an extent as to render it possible to grow profitably susceptible plants on the land. The question of cost must enter into all calculations of quantity to be. applied. On a general farm where the same results can be obtained by growing non-susceptible crops for three years, the cyanamid method would be too costly; but on a truck farm or garden, the case is different. Here many growers regularly use, especially on seed beds,


as much or more ammonia in the fertilizer as is contained in a ton and a half of cyanamid. As cyanamid is at least as cheap as other sources of ammonia, the trucker gets the vermicidal action for nothing. If the dose runs over 1.5 tons per acre, the excess must be charged to vermicidal advantages. When the material is applied some time before the crop is planted, much of the material is doubtless lost.
(2) The best time to apply this.
(3) The best methods of application.
(4) The time that should elapse between treatment and planting. This will vary with the crop, dose, conditions of temperature and especially of moisture and will have to be worked out for each truck crop commonly grown in Florida, under the conditions likely to be encountered. Even the crops that nematodes do not seriously attack will have to be tested, for if they are found to be tolerant of large doses of cyanamid they can be used as a quick crop to occupy the ground between the time of application of the cyanamid and the planting of some highly intolerant plants, such as tomatoes or cucumbers.
As we have seen, the burning effect of .cyanamid is much more pronounced if the soil is dry.
GREENHOUSE EXPERIMENTS
A bench in the greenhouse was filled to a depth of five inches with infested soil and then divided into seven compartments of approximately a square yard each. In this bench it was possible to control conditions better than in the field and especially to eliminate the migration of nematodes into the treated soil.
Section 1 was treated with cyanamid on March 29 at the rate of 4 tons per acre. The material was mixed with dry soil and then wet down. Unfortunately at this time, the importance of a thoro mixing was not so well appreciated as it is now and the mixing was not so thoro as it should have been.
Section 2 was treated with cyanamid at the rate of 2i/2 tons per acre. This was dissolved in water but the wet soil was stirred thoroly.
Section 3 was treated with the same dose as section 2 in water, but the soil was not stirred; the water was depended upon to carry the cyanamid down.
Section 4 was not treated, being left as a check. It was thoroly wet down.


Section 5 was treated with cyanamid at the rate of 2 tons per acre, applied as in section 2.
Section 6 was treated at the rate of 1440 pounds per acre, stirred in dry and then wet down.
Section 7 received the same dose as section 6 but it was added in solution.
On April 8, these plots were planted to tomatoes, cabbages, peppers, and lettuce. On the three plots that received the heaviest doses, a very few vegetable seedlings appeared. On the three receiving the weaker doses they appeared but soon died. Section 1 was almost sterile on May 21, there being even very few weeds. On the check, section 4, there was a vigorous germination of both weed and tomato seed, the latter were heavily infested with nematodes and soon died.
The bench was neglected during the summer, not even being watered except by rain which leaked thru the roof.
On September 11, the bench was again planted to lettuce, cabbage, celery, carrots, cucumbers, and tomatoes. To our surprise some of these plants on sections 1, 2, and 3 also died. Evidently, the fact that the plots were dry during the summer prevented the decomposition of the cyanamid. A few cabbages in one plot only, section 1, lived. Replantings in this section showed scorching of the tomatoes as late as January 1916. These recovered, however, and made good growth. Up to the present time all plants grown in this section have been free from nematodes excepting those grown in the small portion where the September planting of cabbages was not killed. Apparently, in the insufficient mixing, this portion failed to receive its share of cyanamid.
Section 2 has remained entirely free from nematodes. Evidently a dose of 2% tons per acre on shallow soil will kill all nematodes. Of the seeds planted in November, celery was not burned at all, cabbage showed some burning, lettuce considerable, cucumbers and tomatoes burned badly.
On section 3 the effects were about the same as far as burning was concerned, but there were a few nematodes on these plants. This coincides with other experiments which indicate that one does not get as good results when the cyanamid is added in water. The top layer of the soil seems to absorb the material.
Section 5 showed one corner next to the check to be heavily infested, the remainder free. This distribution led to the suspicion that the partition between the sections may have worked


loose; a suspicion which was verified by examination. We believe the nematodes were exterminated in this section by a dose of 2 tons per acre.
By May, 1916, there were a few knots noticeable on tomatoes in section 6. Up to this time none have been noticed. Probably 1440 pounds per acre is a little too small a dose to do thoro work of eradication, altho it greatly reduced the numbers of the nematodes.
Section 7, with the same dosage as section 6, but added in solution, had some root-knot, tho markedly less than the check.
In section 4, check, all plants were so heavily infested with nematodes that they made very little growth.
In November, a new series of thirteen one-hundredth acre plots were treated, using from 420 to 3600 pounds per acre. On three of these plots the material was added in solution. Two were left untreated for checks. On the other nine about half of the material was applied as a top dressing and plowed under, the other half then was added and mixed with the soil by means of a disk harrow. On all these plots which received 1500 pounds or less per acre nematodes are now found. On the plots which received one and two tons respectively, none have yet been found on the winter crop of lettuce, beans, radishes, etc. The spring crop has not been dug up.
TABLE 18
Time in Weeks Between Treatment of Soil and Planting of Seed Quantity cyanamid applied, pounds per acre
Radishes .......................
Turnips .........................
Cabbage and collards...
Celery ...........................
Roselle ...........................
Rape...............................
Lettuce...........................
Pepper ...........................
Peas...............................
Watermelons ...............
Cantaloupes .................
Cowpeas.........................
Beans .............................
Irish potatoes...............
Tomatoes .....................
Cucumbers...................
4000
3000 2000
-to 4 ; -to 4
-to 2 1
8 to 12 -to 28
to 8
-to 8
3 to 24 i 3 to -
to 12
-to 12 4 to 14
lto 5 8 to 8 lto 5 4 to -to 8* -to 2 -to 12 lto 6 20 to 24
1500 1000 800
-to 1 -to 2 -to 1 ............ -to 1 -to 1 lto 1
l*to2 lto 8 -to 1 lto 2 -to 6 lto lto 4 -to 1 lto 2 lto 1
4 to 6 lto 2

3 to 7 3 to 6 3* to 4
-to 12 1 to lto
8 to
*Trace of burning.
From these plots and other sources we have gathered the data in table 18 which shows the relative tolerance of plants for


cyanamid, and the time which should elapse between the application of the material and the planting of the crop for several different doses. This data is provisional.
In table 18 the first number under each dose denotes the maximum number of weeks between the treatment of the soil and of planting, when serious burning occurred. The second number denotes the minimum time between treatment and planting, when no serious burning occurred. In other words, the earliest safe time to plant the crop named opposite the numbers lies somewhere between them. The second number represents the shortest time we have observed to be safe. Doubtless further experiments will cut this down in most cases.
EXPERIMENTS AT FORT PIERCE The foregoing experiments were conducted at Gainesville and apply only to the type of soil used there. On our advice and under our direction, the County Demonstration Agent for St. Lucie County, Mr. McLendon, undertook some experiments at Fort Pierce.
The entomologist visited these plots in June, 1916. They have developed the following important points :
1. Cyanamid can be applied to pineapples in the field in doses as heavy as 1500 pounds without injuring them. The nematodes on pineapples were not exterminated but there seemed to be fewer than on the untreated plants. The pineapples had a much better color but this was mostly due to the fertilizing value of the cyanamid.
2. Apparently, on the very sandy soils of the pineapple fields, a much smaller dose is effective than at Gainesville, and
3. The material leaches out much more rapidly.
Some of the very light pineapple soil was treated with cyanamid at the rate of 1500 pounds per acre and a few tomatoes were set out at once. Altho there was severe burning at first, the plants recovered and made good growth and were nearly free from nematodes. On Gainesville soils the tomatoes died when set out on land with that large an application, even after a lapse of several weeks. Furthermore, a dose at least twice as large would have been necessary to exterminate the nematodes as thoroly. Evidently the character of the soil will greatly modify the procedure outlined here for Gainesville soils.


Insects of the Year
The (most unusual insect outbreak of the year was that of Diabrotica vittata. Altho we have occasionally received the striped Cucumber-beetle from West Florida, and the Station collection contains a specimen from Gainesville, we had never until this year received a complaint from South Florida, nor is the insect even mentioned in the Station literature. The first complaint came from Denaud, Lee County, on October 18 and complaints continued to come in until the last of April. They came from as far north and west as Madison, but the majority were from the east coastSt. Lucie and adjoining counties. The insects were not observed about Gainesville. In the Northern States this insect usually confines its attacks to young cur-cubits but according to our correspondents they destroyed fields in which plants were three or more feet long. They killed bearing okra plants as well as watermelons, and even attacked Irish potatoes.
The most interesting host was citrus, on which they destroyed the young growth. This is the first record of any Diabrotica attacking citrus in Florida, altho our common D. 12-punctata is often abundant in corn fields, especially in the western part of the State. It is interesting to note that another species of this genus is a minor pest of citrus in California.
Aleurothrixus howardi, the Woolly Whitefly, continues to extend slowly into the regions immediately adjacent to its previous range. We have received it from Palmdale in the extreme southeastern part of DeSoto County. It is probable that all citrus communities in that county are infested and the same may be true of Pasco County. The most serious outbreak occurred in Brevard County, about Melbourne, Cocoa and the southern end of Merritt's Island. Specimens received from Georgiana on April 21, consisted of eggs and adults as well as pupae, and others from Melbourne, on May 4, were mostly in the first and second larval stages. This is nearly a month earlier than the time heretofore recorded for the appearance of the spring brood (see Bulletin 126, p. 90).
The Cowpea Pod-weevil (Chalcodermus aeneus) appeared more commonly than usual during the spring of 1916. It seems to be especially attracted to the California black-eyed variety of cowpeas. In a field near Gainesville where that variety was growing beside the clay variety, there was less than a tenth as


many larvae in the latter as in the former. It was common on radishes at Gainesville in May.
The June-bug (Anomala marginata) likewise seemed to be especially abundant during June, 1916. It was received from Levy to Escambia counties and reported as doing serious damage to a great variety of trees and grapes.
The Twig-Girdler (Oncideres cingulatus) was the cause of several complaints from the lower East Coast where it was attacking "Australian pines." The curious thing about this attack on an introduced plant by a native insect was that practically no eggs were laid in the girdled twigs. Only one egg was found in the dozens of girdled twigs examined. Evidently the plant stimulates the girdling instincts of the females but not the egg-laying instincts.
Respectfully,
J. R. Watson,
Entomologist.


REPORT OF THE PLANT PATHOLOGIST
P. H. Rolfs, Director.
Sir : I submit the following report of the Plant Pathologist for the year ending June 30, 1916.
gummosis
This has been the major problem for the year and the same plan of investigation was followed that has been reported in previous years.
Gummosis has shown considerable activity within the last few months. Reports from different localities indicate a reappearance of the trouble in groves where it had formerly been treated and where it was considered well under control. The disease shows a tendency to heal apparently or remain dormant or quiescent for varying periods and again break out in active form. The conditions predisposing such outbreaks or; periods of dormancy have not been traced as yet to any one factor or set of factors.
In a former report (Fla. Agr. Expt. Sta. Rpt., 1914, p. lxi.) some notes were published on a number of diseased areas that had been kept under observation for a period of thirteen months. These same areas have been kept under observation now for a period of more than three years and the data obtained is con--sistent with that of the former report.
Eighteen areas were selected representing as nearly as possible the different stages in the development of the disease. Ten were active at the time of selection and eight were chosen that had apparently healed. Notes were taken on the condition of these areas two or three times during each year thruout the period. In table 19, the condition of each area is given as it appeared for that year. All areas were considered active that showed any recent killing of tissues with gum flow. Where new tissues were forming and there was little or no gum flow, the area was considered healing. Healed areas represent those in which all gum flow had ceased and where the dead surface bark had scaled off leaving a clean scar.
Seven of the active areas noted in the beginning have apparently healed and remained so the last two years. One has remained active during the entire period and two apparently healed for a time and became active again. Of the eight areas that were considered healed at the beginning, two have re-


mained so thruout the period. Five have shown an active period for a time and then apparently healed again. One has become active and remained so the last two years.
TABLE 19
Condition op Gummosis Areas Under Observation
Area 1 2 3 4 5 6 7 OO.l .9 10 11 12 13 14 15 16 17 18
1913... .A A h h A A h A A h A A h h A A h h
1914... .A h A h A h h A A A h A h A A A A A
1915... .h h h h h h h h G h A h A h A h h h
1916... h h h h h h h h h h A h A h A A h h
a, active. h, healed. G, healing.
inoculations
In the last season several series of inoculations have been made into large bearing citrus trees. Diseased bits of tissue from active Gummosis areas have been used as the inoculum. So far, sufficient time has not elapsed to make a definite report on them.
A study is being made of the fungus and bacterial flora associated with Gummosis areas to determine what relation they bear to the disease. Cultures have been taken in the field from different types of areas on different citrus hosts and some of the organisms isolated are now under study. Phomopsis citri and Diplodia natalensis have been isolated from Gummosis areas repeatedly but when these fungi are introduced into healthy citrus bark they have failed thus far to produce the characteristic areas typical of Gummosis.
control experiments
Experiments at Weirsdale, Fla., for the control of Gummosis by means of antiseptics have been continued and the results from the second season's work have not shown so promising. These experiments will be continued thru the present season and a full report of the results will be, given in a future report.
Melanose
The pruning experiment for the control of Melanose that was begun in 1913 was continued last season with some modification in the original plan. This experiment is being conducted in a grapefruit grove and the last three years the fruit has not been picked from this grove until late in the season. This has interfered with making some of the prunings at the time plan-


ned, so it was decided this season to change the experiment to avoid this interference. As the experiment was first outlined (Fla. Agr. Exp. Sta. Rep., 1913. p. lxxxv) a winter and summer pruning and a combination of the two were provided for. There are four blocks of trees and block 1 has been left un-pruned as a check. Block 2 was to be pruned in January and June. Block 3 to be pruned in January, and block 4 in June. The first pruning, made in 1913, followed this schedule. In 1914 the January pruning was delayed until the first part of April on account of the late date on which the fruit was picked. The trees pruned at this date did not seem to do so well as the other trees in the experiment and they seemed to suffer more from attacks of withertip later in the season.
In 1915, the fruit was not picked until the last of April and the January pruning was omitted for that year. The same occurred in 1916 when it was decided to change, and make all prunings in June. The summer pruning has given very good results in reducing the amount of injury from attacks of Mel-anose and has not resulted in any perceptible injury or shock to the trees.
The summer pruning is probably more convenient for the grower since it can be done at a time when other duties of the farm are not so pressing and when labor is cheaper and more readily available. Since the tendency at present is to hold the grapefruit crop over for the late spring market, it is advisable to make prunings in such groves during the summer season.
In table 20 are given the percentages of the different grades of fruit from each block of the 1915 crop. The percentages of the different grades of the 1913 and 1914 crops are also given for comparison.
TABLE 20
Record of 1913 Crop
Block
No. of
trees
When Pruned
Percentage of
Brights
Seconds j Russets
No. 1 No. 2 No. 3 No. 3* No. 4
12 16 10 6 12
Jan. Jan. June
Check
Jan. & June
23 47 40 56 34
74 3
52 1
57 3
43 1
62 4


Record of 1914 Crop
Block When Percentage of
No. of
trees Pruned Brights Seconds Russets
No. 1 12 Check 12 73 15
No. 2 16 Jan. & June 35 60 5
No. 3 8 Jan. 34 63 3
No. 3* 8 Jan. 56 41 3
No. 4 12 June 45 53 2
Record of 1915 Crop
No. of When Percentage of
Block
trees Pruned Brights Seconds Russets
No. 1 12 Check 0 62 38
No. 2 16 2 73 25
No. 3 8 4 68 28
No. 3* 8 4 68 28
No. 4 12 June 31 52 17
?Carefully pruned by the writer.
It must be remembered that the pruning of blocks 2, 3 and 3* was omitted for the last season, which accounts for the poor showing made by them in the 1915 record. Melanose was unusually abundant in this grove during the summer of 1915, and a great part of the injury occurred late in the season. This has been the most severe attack experienced since the pruning experiment has been in operation.
Citrus Canker
Investigation of this disease the past year has been confined chiefly to laboratory studies of the organism. Special attention has been given to the growth and behavior of Pseudomonas citri Hasse in soil cultures, and attempts have been made to recover the organism from the field soil that has been collected from under citrus trees that were infected with Citrus Canker.
Bulletin 128, Citrus Canker III, was published in November, 1915, and in this the latest information and facts concerning the disease were summarized.
Doubtful specimens of Citrus Canker have been submitted to the Department from time to time for accurate determination, and many tests have been made to establish the presence or absence of Ps. citri in such specimens.


SOIL CULTURES
Ps. citri has been cultured continuously in sterilized soil for a period of more than a year and the organism has maintained its vitality and apparently lost none of its virulence during this period. A marked resistance to desiccation has been exhibited by the organism. In moist soil a rapid multiplication takes place and the organisms readily penetrate to a considerable depth in such soil.
Previous to this experiment the writer did not think that the canker organism would survive long after being introduced into the soil. It was considered hardly probable that an organism of such virulent nature, that confined its attacks to the aerial part of the host would survive long as a saprophyte in the soil. The results from the experiment have demonstrated, however, that the organism grows readily on sterilized soil in a moist condition and that its virulence is not impaired by continuous culture on such medium. The bacteria are also capable of surviving for many months in thoroly air-dried soil, and still retain their virulent nature, tho their numbers are greatly reduced.
A series of soil cultures were made in the spring of 1915, and have been kept under observation to date. These cultures were prepared as follows:
Six large test tubes were filled with soil to a depth of four or five inches. The soil was chiefly sand with a small percent of clay and humus, and similar to the ordinary upland soil of Florida. It was thoroly moistened, but not enough water was added to saturate. The tubes were plugged and sterilized in the autoclave for thirty minutes at fifteen pounds pressure. After twenty-four hours each tube was inoculated with one cubic centimeter of a suspension of Ps. citri from a pure culture in sterile water. These six tubes were inoculated April 30, 1915, and numbered from 1 to 6. All tubes were incubated at room temperature thruout the period which ranged from 11 to 35 C, the average mean ranging from 22 to 25 C.
Tests were made of certain tubes at varying intervals for the presence of Ps. citri. These tests were made by plating a small amount of the soil from the tube to be tested in nutrient agar and noting the colony development in the plates. When tests were made from moist soil a small amount of the culture equal to about 0.1 or 0.2 of a gram in weight was removed on the point of a scapel. This was transferred to a large drop of


water in a sterile petri dish. The plate was then poured and incubated.
Table 21 gives the date, number of different tubes tested and a statement of the presence of the organism in the amount of soil tested on that date.
TABLE 21
Date
May-May June July Aug. Sept. Sept. Oct. Oct. Dec. Apr. Apr. May
8,1915. 15,1915
3.1915. 10,1915. 24,1915
2,1915 30,1915. 19,1915 28,1915.
12.1915.
1.1916. 8,1916.
30.1916.
Tubes tested
Nos.
-Nos.
Nos.
Nos.
Nos.
No.
Nos.
No.
No.
Nos.
Nos.
No.
Nos.
1, 2, 3, 4
1, 2, 3, 4
1, 2, 3, 4
1, 2, 3, 4
1, 2, 3, 4 3
1, 2, 4
2 2
2, 2a, 4 2, 2a, 4 4
1, 2, 5
Presence of Ps. citri
Abundant Abundant Numerous Numerous Numerous in Few in dry Few in dry Few in dry Numerous Few in dry Few in dry Few in dry Few in dry
1 and 3, few in 2 and 4
soil, numerous in moist
soil, numerous in moist
soil, numerous in moist
soil, numerous in moist
soil, numerous in moist soil
soil, numerous in moist
During the first tests soil was taken only from the surface of these tubes and while it was in a moist condition the numbers of organisms in the small amounts tested were large. As the soil became dry near the surface the numbers of organisms that survived were greatly reduced and larger amounts of soil were used in these tests. About one or two grams of dry soil was taken for each test and the numbers of organisms obtained from such samples varied from a few to 100.
The dry top soil in tube No. 1 was poured off into another tube after the culture had been inoculated for about three months. Tests were made from the remaining soil as long as it-remained moist. The last test made of tube No. 1, May 30, 1916, was, however, from the dry soil that had been previously removed. This soil was thoroly air-dry and could be poured like sand, and had remained in this air-dried condition for at least nine months. About five grams of this soil were used for each test and from 75 to 100 organisms per sample were obtained. The dry top soil was poured from tube No. 2 six months after the culture was first inoculated, and numbered 2a. This soil when tested showed about 75 to 100 organisms per sample. Sterile water was added to remoisten the soil and later tests with small amounts (0.1 to 0.2 grams) showed an increase of many hundred fold in the number of organisms present. The remaining soil in tube No. 2 was remoistened at intervals and


a corresponding increase in the number of organisms present was noted whenever moisture was added.
Tube No. 5 was not opened from the time it was inoculated, May 30, 1915, until the final test, May 30, 1916. The soil was thoroly air-dried and would pour like sand. The culture was well shaken to obtain a composite mixture of top and bottom soil and tests from this tube also gave living organisms.
Tests of newly-made cultures, ten days after inoculation, showed that the organisms were rather uniformly distributed through the soil even at depths of 4 to 6 inches.
Infected soil from the foregoing cultures has been applied from time to time to healthy citrus foliage and in all cases canker infections have resulted. Where moist soil from these cultures has been used a heavy infection was usually obtained. The air-dry soil gave in most cases only scattering infections. The soil was applied in most cases to the upper surface of the leaves and the trees were then thoroly drenched with a fine spray and kept in a humid atmosphere for at least 48 hours. The results are given below.
Experiment I, Sept. 2, 1915
Seven citrus trees in pots. Young foliage. Dry top soil applied to upper surface of leaves from tube No. 3. Foliage thoroly sprayed and trees kept in a humidor 48 hours.
4 Grapefruit seedlingsscattering infection.
2 Rough Lemon seedlingsscattering infection.
1 Budded Grapefruitscattering infection.
Seven citrus trees in pots. Young foliage. Moist soil from the bottom of tube No. 3 applied to the upper surface of the leaves. Foliage thoroly sprayed and trees kept in a humidor 48 hours. 4 Grapefruit seedlingsscattering infection.
2 Rough Lemon seedlingsscattering infection. 1 Budded Grapefruitnumerous infections.
Thirteen citrus trees. Young foliage. Checks. Foliage sprayed and trees kept in a humidor along with the above. 8 Grapefruit seedlingsno infection. 4 Rough Lemon seedlingsno infection. 1 Budded Grapefruit seedlingno infection.
Experiment II, Jan. 4, 1916
Potted orange tree, young foliage. Moist soil applied to the upper surface of the leaves and the tree thoroly sprayed. Kept in a humidor 48 hours. Soil from culture 2b used. This was a sub-culture made from tube No. 2 by transferring a small amount of infected soil to a tube of sterilized moist soil. After incubation for several days the culture was used above.
A heavy infection resulted on leaves and stems.
Experiment III, May 8, 1916 Two potted grapefruit trees, young foliage. Soil from tube No. 4 applied to 4$ leaVfig. Foliage sprayed and trees kept moist for several days. Good infection. Twenty-two leaves infected.


Experiment IV, May 31,1916
Potted orange tree, young foliage. Sprayed, and air-dry soil from culture No. 5 sprinkled on the upper surfaces of the leaves.
Heavy infection resulted. Twenty-eight infected leaves out of thirty-five: treated.
TESTS OF FIELD SOIL
Since Ps. citri is capable of growing in sterilized soil, and surviving for long periods in such soil, under less favorable conditions for growth, it may be expected to behave in a somewhat similar manner when introduced into field soil under natural conditions. These organisms may not become so numerous or so generally diffused in field soil as they are found in cultures, for the environment is very much less favorable and there are many factors in natural soil that would tend to prevent or hold their development in check. It is believed, however, that these organisms may find certain more favored spots or areas in the soil where they become established and survive for long periods, and that these areas may prove to be centers from which the organisms are ultimately spread.
Soil under canker infected trees is subject to the introduction of these bacteria during every period of rain and no doubt, many of the organisms find a favorable habitat in such soil, and later find their way back to the foliage again thru certain carriers. Field observations seem to bear this out.
Samples of soil taken from beneath trees that were infected with Citrus Canker have been tested at different intervals for the presence of Ps. citri, and while a majority of these tests have given negative results, in a few cases the presence of the organism has been established in the sample tested.
It was not found feasible to obtain the organism by dilution culture methods, and the samples were tested by applying washings from the same or small amounts of the soil direct to young^ healthy citrus foliage. Where canker infection occurred on the foliage thug treated, the presence of Ps. citri in the sample of soil tested was definitely established. The same interpretation of the negative results would hold true only in a certain measure, for in most cases small amounts of the samples were used, owing to the limited facilities for making these tests. An absolute test of these samples would have required the use of the entire amount of the soil and a larger number of citrus trees than were available at that time.
The samples were collected by the canker inspectors and sent


to this Department for testing. Below is given in condensed form the notes on these samples and the results of such tests.
Sample No. 1. About VA pounds of soil, collected December, 1915. Soil taken at one point from 2 to 6 inches below the surface, from an area beneath a canker-infected tree that was burned in May, 1915.
Jan. 4, 1916, sample tested. Soil washings from a part of the same; 43 leaves treated, 8 developed canker, a total of 14 spots.
Feb. 1, 1916, sample again tested. Soil washings of entire sample; 147 leaves treated, no infection.
Sample No. 2. About 3 pounds, collected in December, 1915. Soil taken at a depth of 2 to 6 inches below the surface, from an area beneath a canker-infected tree that was destroyed in November, 1914.
Jan. 4, 1916, sample tested. Soil washings from a part of sample; no infection.
Sample No. 3. About 3 pounds of soil collected December, 1915. Soil taken at depth of 4 to 6 inches below the surface, from an area beneath a canker-infected tree that was destroyed in July, 1915.
Dec. 12, 1915, sample tested. Washings from a part; no infection.
Jan. 4, 1916, sample again tested. Washings from a part of sample; 32 leaves treated and 4 developed canker infection.
Sample No. 4. About 3 or 4 pounds of soil collected January'5, 1916. Surface soil at one point for a depth of 2 inches, taken from beneath a living tree heavily infected with Citrus Canker.
Jan. 11, 1916, sample tested. Soil washings from a part; no infection.
Sample No. 5. About 3 to 4 pounds of soil, collected Jan. 5, 1916. Soil taken at a depth of 2 to 4 inches below the surface, from under the same tree as sample No. 4.
January 11, 1916, sample tested. Soil washings from a part; heavy infection, 27 infected leaves out of 34 treated. Many spots to the leaf.
Sample No. 6. About 3 pounds of soil, collected Jan. 5, 1916. Cross section of the soil, 4 to 5 inches in depth. From under the same tree as samples 4 and 5, at a different point.
Jan. 11, 1916, sample tested. Washings from a part; no infection.
Sample No. 7. About 4 pounds of soil, collected Jan. 14, 1916. Taken at a depth of not more than 2 inches, from an area where a lime tree heavily infected with canker had been burned.
Jan. 22,1916, sample tested. Soil washings of entire sample; no infection.
Sample No. 8. Less than % of a pound, collected Dec. 4, 1915. Taken at a depth of about 6 inches below the surface, from a spot where a canker-infected tree formerly stood.
March 11, 1916, sample tested. Part of the sample sprinkled on surface of young citrus foliage; thoroughly sprayed; kept in a humidor 5 to 6 days; no infection.
Sample No. 9. Less than % of a pound. Collected Dec. 4, 1915. Taken at a depth of about 6 inches, from an area where a canker-infected tree had been destroyed.
Mar. 11, 1916, sample tested. Part of the soil sprinkled on the surface of young citrus foliage, thoroly sprayed and kept in a humidor 5 or 6 days; no infection.
Sample No. 10. Less than % of a pound. Taken at a depth of about 6 inches, from a canker-infected grove where a diseased tree formerly stood.
Mar. 11, 1916, sample tested. Part of the soil sprinkled on young citrus foliage, thoroly sprayed and kept in a humidor for 5 or 6 days; no infection.
Lightning Injury
Several cases of injury to young citrus trees from lightning have come to our attention within the last year. The trouble has been reported from widely separated areas in the State and


while the total loss in most cases has been insignificant, the citrus growers in the affected localities were very much concerned over what appeared to be a new and serious citrus disease.
Specimens of the injury were received from different localities and the reports that accompanied the same seemed to indicate that this was a new disease which appeared suddenly and spread rapidly from one or more badly infected trees as a center. Specimens were studied carefully in the laboratory from time to time but nothing definite regarding the cause of the trouble resulted from such studies. Attempts were made to transfer the disease to healthy citrus foliage by contact with diseased specimens but the results obtained were entirely negative. Later, a visit was made to the groves in order to study the disease in the field. Some recent outbreaks were observed in the vicinity of Lake Alfred, Winter Haven, Haines City and Lakeland. Six different places where small grove trees had suffered from injury were visited and the writer was fully convinced that the injury in each case was primarily caused by lightning.
Usually one or two trees in each injured lot were more severely affected than the others. Numerous peculiar spots or blotches were noted on the surfaces of the young green shoots and occasionally a large branch or limb was observed on which the leaves were withered. The trunks were not split or lacerated as is usually the case with other trees when struck by lightning. In two instances a narrow strip of dead bark was traced from the top of the tree down the trunk to the ground but this was not split or ruptured. At the surface of the ground an area of dead bark encircled the bases of these trees. On trees adjacent to the more injured ones, scattering twigs or shoots were found that were spotted or blotched in a similar manner. Clusters of three or four shoots of the same age and in the same condition of growth were frequently observed in which one or two shoots were spotted or blotched while the others were entirely free.
Trees, from a few to a dozen or two, may show varying degrees of injury when lightning strikes in a grove. Those adjacent to the one receiving the full shock usually show more or less injury. In some cases, however, it was observed that certain trees in close proximity to those that were severely injured


Fig. 10.Spots on young citrus twigs due to injury by lightning. Natural size.
were passed over or missed, while other trees beyond showed injured twigs.
Lightning injury to citrus trees has been previously observed in the State but apparently no published report was ever made of it. In a letter to the writer Prof. H. S. Fawcett states that he observed in Florida some years ago certain injuries on citrus trees that he concluded were due to lightning and he mentioned two localities from which the injury was reported. Specimens of lightning injury were received from these same localities last season.


APPEARANCE
The most striking feature of the injury is the characteristic spots or blotches produced on the surface of the young green shoots and twigs. In the first stage of development these are represented by pale greenish-yellow to yellowish areas outlined on the surface of the bark, which vary much in size and shape. In some cases the spots cover only a few square millimeters of surface and again specimens are observed where the entire surface of the twig is involved for a distance of three or four inches. The leaf and leaf petiole in such instances seem to escape injury- Spots are frequently found encircling the base of the petiole and in specimens where the entire twig is girdled or invested, the green leaf petioles and leaves stand out in marked contrast against the discolored areas.
In later stages the spots and blotches became yellowish-brown and are raised above the healthy tissue. The surfaces are smooth for a time and are covered by a thin glazed membrane which may become more or less bleached with age. The tissue beneath this covering is soft and somewhat spongy, being composed of a few layers of dead ,, ... J.
_ Pig. 11.Lightning injury to young citrus twigs,
cells. In most Cases showing green leaf petioles surrounded by dis-the spots seem to colored areas. Enlarged two times.


penetrate only a few layers of the surface cells and the cambium is rarely affected. The growth of the cambium from below gradually elevates the deadened areas and eventually the surfaces of the spots rupture, usually by longitudinal fissures. The surfaces then become ragged or lacerated and finally slough off leaving a brownish, roughened scar.
The first stage of the injury noted is probably due directly to lightning. In this stage the areas are not visibly depressed but the tissue appears dry and the cells somewhat collapsed. Tissue thus weakened offers a ready means for the entrance of fungi and bacteria which may rapidly complete the destruction of such. A species of Colletotrichum, probably C. gloeosporiodes is constantly found associated with the spots and blotches and no doubt this fungus has an important bearing on their later development.
When a spot or blotch once forms there is apparently no tendency to increase in size or extend beyond its original limit.
On older branches and limbs which were protected by an outer corky layer, no spots or blotches were noted and only in one or two instances were blotches found on leaves that could have been attributed to the same cause.
Lemon Brown Rot Fungus
Within the past few months a species of fungus which resembles Pythiacystis citrophthora Sm. & Sm. has been isolated from gumming citrus trees at different points in the State. The writer first isolated the fungus in March of the present year at Weirsdale, Fla., from an orange tree that showed typical symptoms of Foot Rot or Mai di gomma. The same fungus was later obtained at two other points in the State and it has since been found in several different localities. So far it has been isolated only from diseased areas that were typical of Foot Rot infections.
Healthy lemons inoculated with the fungus developed a brown rot similar to that produced by P. citrophthora. The fungus differs slightly from the latter in certain growth characters but a sufficient comparative study of the two organisms has not yet been made to determine definitely whether they are the same or different species. The fungus is at present under study to determine what relation it bears to Gummosis and Foot Rot in Florida.


This same fungus was isolated by Prof. H. S. Fawcett in 1914 at Palmetto, Fla., from a grapefruit tree that showed typical symptoms of Foot Rot or Mai di gomma (Phytopathology Vol. 5, No. 1, p. 66, 1915). The writer obtained a culture of this isolation at the time but no detailed study was made of the fungus and the culture was finally lost. A second culture of this isolation and a culture of a California strain of P. citro-phthora were recently obtained from Prof. Fawcett. The fungus recently isolated by the writer is apparently identical with the fungus Fawcett isolated at Palmetto and which he considers to be Pythiacystis citrophthora.
Citrus Diseases
Citrus Scab (Cladosporium citri Mass).This disease has been quite active the last season, especially on young grapefruit trees. Attacks on fruit were not so severe as in past seasons. The fruit of the coming season, especially from the early bloom, has largely escaped injury this year owing to the dry conditions that prevailed during the spring months.
WiTHERTlP (Colletotrichum gloeosporioides Penz).Considerable injury from this disease has been reported within the last few months. This has been especially noticeable in groves that suffered from the frosts of last March and in groves that have been poorly cared for.
Stem-End Rot (Phomopsis citri Fawcett).This disease was not troublesome last season and was only reported from a few localities. The dry weather conditions that prevailed during the greater part of the picking season was no doubt a factor in keeping this disease in check.
Pecan Diseases
The work on pecan Dieback has been along the same lines as reported last year. Mr. J. Matz has carried out the investigation and I include herein his report of the work for the past season together with a report of a new fig disease of which he has recently made a preliminary study.
Respectfully,
H. E. Stevens,
Plant Pathologist.


REPORT OF THE ASSOCIATE PLANT PATHOLOGIST
P. H. Rolfs, Director.
Sir: I submit the following report for the year ending June 30, 1916.
Diseases of Vegetables
The work with diseases of vegetables has been conducted this year as far as practicable along lines followed during the preceding season, 1914-1915. Chief attention was given to seed bed diseases, chiefly to damping off." In connection with these diseases, some time was given to investigation of seed disinfection of several of our most important vegetables. Certain attention was given to some bacterial diseases not yet quite well known, such as the black heart" of celery and lettuce. Some work has been done with an apparently new fungus disease of tomato fruit which is here being referred to as the buckeye tomato fruit rot. The remainder of the writer's time was spent on a preliminary inquiry into the nature of pineapple wilt, a new item in the project, and on several minor problems of vegetable diseases that require immediate attention.
Damping Off in the Seed Bed
A brief general discussion of the so-called damping off is given in a previous report (Fla. Agr. Exp. Sta. Rept., 1915, xcv-xcvli). It is stated there that the Rhizoctonia has been found to be the most common cause of the disease in Florida. The study during this year fully supports that statement. During both seasons certain Fusaria that probably were responsible for a local damping off were found in only a very few instances. In no instance was Pythium debaryanum Hesse isolated last year and only in one case was it isolated during the work of this yearwhen it was found developing profusely on young cucumber plants growing in a muck soil in our greenhouse. A typical damping off was observed in this case. The Pythium debaryanum at present is being grown in pure cultures in the laboratory and as it was growing quite profusely on the plants affected with damping off and around them on the soil, it is-evident that the fungus can grow readily in Florida.
During this season Rhizoctonia was isolated again from the same kinds of plants affected with damping off as were used last year, namely, cabbage, lettuce, celery, cauliflower, eggplant,


and tomato. It was also obtained from damping off of castor bean, cultivated amaranthus, watermelon and cowpea plants; from a pod rot of garden bean and velvet bean and from a rot of tomato fruit.
Fig. 12.Young lettuce plants grown in a wooden flat with soil which previous to sowing the seed was thoroly infected with Rhizoctonia so'ani Kuhn. A, part of flat treated immediately before sowing with V2 percent solution of copper sulphate at the rate of 500 cc. per square foot of soil surface; no damping off. B, check; considerable damping off is visible.
Eight strains of Rhizoctonia isolated this season (from lettuce, castor bean, amaranthus, watermelon, cowpea, garden-bean pod, velvet-bean pod and tomato fruit) and one received from Dr. B. M. Duggar of Missouri Botanical Garden were used for inoculation of seedlings of lettuce, celery, eggplant, pepper and tomato. The inoculations were made in one series by placing bits


of pure cultures of the different strains of the Rhizoctonia between the young plants and in another series by a thoro inoculation of the soil with the same strains of the fungus before sowing the seed. The soil was sterilized previous to the inoculation and sowing, with 1 to 50 solution of formalin at the rate of one quart per square foot of the soil. The experiments were carried on in the greenhouse in wood flats 1 foot square and 3 inches deep. These flats contained only about 300 cubic inches of sandy soil soaked thoroly with the formalin solution, of which not more than one quart was needed. Some additional inoculations were carried out in fresh field soil without previous disinfection. The result was the same as with sterilized soil. Some of the strains of Rhizoctonia were tried also on young plants of cauliflower, cabbage, cucumber, garden bean, cowpea, watermelon, beet and castor bean, and.proved able to produce damping off. The different strains of Rhizoctonia were cultivated for inoculation purposes and for morphological comparison entirely on bean- and cowpea-pod plugs as this medium has been found quite satisfactory for the purpose.
The result of the work of last year, 1914-1915, and of this year leaves, no doubt, first, that here in Florida, during the. last two years, Rhizoctonia has been the most common cause of the damping off of lettuce, celery, eggplant, tomato and several other cultivated plants; and second, that the different strains of Rhizoctonia isolated from all these different plants can produce damping off of every host tried in this work.
From a morphological viewpoint, all the isolated strains of Rhizoctonia are so much alike that they might properly be considered as belonging to the same species.
On a previous occasion the writer stated (Fla. Agr. Exp. Sta. Rept., 1915) that the Rhizoctonia causing damping off of the plants under consideration is probably the same as the one affecting potatoes, or is closely related to it. At present it can be stated that there is enough evidence for considering it actually the same organism as R. solani Kuhn; because, first, all of the strains isolated by the writer are physiologically and morphologically the same as the one received from Dr. B. M. Dug-gar as R. solani Kuhn; and second, one of my strains, that from cowpeas developed on young beet plants, a basidiomycete form answering fully the description of Corticium vagum, B & C var. solani Burt. These plants were grown in our greenhouse in


previously sterilized soil, which was then inoculated with a pure culture of that strain of Rhizoctonia.
In concluding the statement of the cause of damping off in Florida, it should be mentioned that in certain instances the disease is produced by activity of some other fungi' (see Fla. Agr. Exp. Sta. Rept., 1915, xcvi) such as certain species of Fusarium, Sclerotia libertiana Fuckel, Sclerotium rolfsii Sacc. and Phomopsis vaxans (Sacc. and Syd.) Hart. The latter has been found to attack only the, eggplants, while the former three are occasionally found attacking almost any of the vegetables cultviated here. Pythium olebaryanum Hesse is mentioned earlier in this report as occurring here. But all these together have been by far the less common cause of the disease than the Rhizoctonia.
control op damping off
From previous work by other plant pathologists on control of damping off, it is evident that the disease can be controlled, at least for a time, by either the steam or formalin methods of soil sterilization. It is almost impossible to find on a Florida farm a steam boiler handy for soil sterilization, therefore, the formalin method, as worked out by J. Johnson (see Johnson, James. The Control of Damping Off Disease in Plant Beds." Wis. Agr. Exp. Sta., Res. Bui. 31; 29-61, 12 Fig., 1914.) which is to saturate the soil with a 1 to 50 solution of formalin at the rate of one-half gallon per square foot of the seed-bed area, has been recommended whenever sterilization was needed. Very commonly tho, the seed beds here are not permanent and can be started each time on new ground, and this has always been recommended whenever new ground was available. But when new ground is not available the majority of growers will be obliged to resort to some method of soil sterilization against the damping off.
control by disinfectants
The steam and formalin methods are efficient, especially the former, but they are expensive and somewhat cumbersome. The writer has been trying during this year some other methods, hoping to find a more practicable one. On a basis of certain considerations suggested by the literature on the subject, and to some extent by personal observation, the following disinfectants were selected for experimentation on control of damping


. off: (1) Sulphuric acid in concentrations of 20, 10 and 5 cc. of concentrated (1.82 sp. g.) commercial sulphuric acid to one liter of water, or correspondingly, 2 percent, \ percent and 0:5 percent solutions; (2) commercial lime sulphur in concentrations of 10, 5, and 2.5 parts of concentrated commercial lime-sulphur (32 Baume) to 100 parts of water or correspondingly 10 percent, 5 percent, and 2.5 percent solutions; (3) ammonia-cal solutions of copper carbonate in concentrations of 2, 1, and V2 parts of the stock solution (3 pints of concentrated ammonia, 26 Baume, diluted with 5 pints of water, in which then is dissolved 5 ounces of copper carbonate) to 100 parts of water, or correspondingly, 2 percent, 1 percent, and 0.5 percent solutions; (4) copper sulphate solutions in concentrations of 20, 10, and 5 grams of the salt to 1000 cc. of water, or correspondingly, 2 percent, 1 percent, and 0.5 percent solutions; (5) calcium chloride; and (6) sulphur flour in the proportions of 20, 10, and 5 grams to one square foot of the seed bed area. The solutions were applied to a very moist soil at the rate of 500 cc. per square foot of the seed bed area.
During the latter part of this year, experiments with all of these disinfectants were carried out in our greenhouse. For these experiments wooden flats 12 by 12 by 3 inches were used. The soil was very light sandy loam, thoroly infected with the Rhizoctonia three days before the seed were planted. For the first experiment, lettuce was used because of all the plants studied by the writer it is most susceptible to damping off.
The soil infected with the Rhizoctonia in one-half of each flat was then treated with one of the disinfectants while the other half of each flat was left as a check. (It was watered at the same time as the disinfection was applied with the same volume of water as that of the disinfectant, if the disinfectant was in the form of a solution.) Then all of the flats in the first experiment were sown to lettuce.
The experiment gave the following results:
1. a Sulphuric acid 2%; no germination.
b Sulphuric acid 1%; very poor germination; damping off present, c Sulphuric acid %%; poor germination (much poorer than in the check); damping off present.
2. a Commercial lime-sulphur 10%; germination slightly poorer than in
the check; damping off present, b Commercial lime-sulphur 5%; germination and damping- off about
" as in the check. c; Commercial lime sulphur 2%%; same as b.


3. a Ammoniacal solution of copper carbonate 2%; no germination.
b Ammoniacal solution of copper carbonate 1%; poor germination;
no damping off. .
c Ammoniacal solution of copper carbonate % %; germination poorer
than in the check; damping off"present.
4. a Copper sulphate 2%; no germination.
b Copper sulphate 1%; poor germination; no damping off. c Copper sulphate normal germination; no damping off (see
Pig. 12A).
5. a Calcium chloride 20 gr.; no germination.
'b Calcium chloride 10 gr.; very poor germination, c Calcium chloride 5 gr.; poor germination.
6. a Sulphur flour 20 gr.; good germination; damping off present.
b Sulphur flour 10 gr.; good germination; damping off present, c Sulphur flour, 5 gr.; good germination; damping off present.
All of the checks showed considerable damping off (see Fig. 12B).
Thus, under the conditions of the foregoing experiment, only the 0.5 percent solution of copper sulphate controlled damping off and did not injure germination and the rate of growth of lettuce up to the time when the above data were taken, which was seven days after the treatment and sowing of lettuce. But, two days later, the half treated with 0.5 percent solution began to show some damping off also.
In the next experiment, performed soon after the first one, the same flats were used with a similar soil inoculated with the Rhizoctonia. in the same manner. Here the seeds were first sown and then the soil treated. This time different strengths of copper sulphate solution were used and besides lettuce other seeds, tomato, eggplant, pepper, and celery, were tried. Five flats were sown to lettuce, and four flats to each of the other four plants. In the case of each kind of plant, one flat was left as a check, one (or two) treated with 0.5 percent solution, and two (or one) with 0.3 percent solution of copper sulphate. In every case 500 cc. of solution was applied to the flat. There is no need of giving detailed results of this experiment at present, for it is sufficient to state that they show: First, that 0.3 percent and 0.5 percent solutions of copper sulphate are not injurious to germination and growth of the five kinds of plants tried; and second, that the 0.5 percent solution of copper sulphate was strong enough either to control entirely or to control to a great extent the damping off during at least five days after the time of sowing and treatment. After that time, in most instances, the disease began to appear. Some additional tests of a few plants were made in the same flats and at about the same time. In one case, two applications of 0.3 percent solution


to the same area were tested. The result was negative and the damping off was worse than where a single application of 0.5 percent solution was made.
One percent, 0.5 percent and 0.3 percent solutions- of copper sulphate were applied directly upon young growing seedlings of lettuce. The strongest solution in every instance caused much injury to the plants (scalding effect); the 0.5 percent solution in one case injured the plants while in another case no ill effect was observed.
From the work done so far it seems to show that a treatment of a seed bed just after the seed is sown, with a solution of copper sulphate of from 0.5 percent to 1 percent strength at the rate of about 500 cc. per square foot of the seed bed surface (the soil should be well moistened previous to the treatment) may prove to be a satisfactory method of at least partly controlling damping off. Much work is needed before any definite conclusion in regard to the best concentration and amount of the solution and its actual efficiency can be obtained.
Seed Disinfection
Because certain seedbed diseases such as the damping off caused by Phomopsis vexans (Sacc. & Syd.) Hart, can be introduced with the seed, it has been considered necessary in connection with the study of seed bed diseases, to do some work on disinfection of the seeds of the most important vegetables; such as celery, lettuce, eggplant, pepper, tomatoes, etc. Very little work along this line was done by the writer in the previous year. Many treatments were made this year, using, with but few exceptions, 1:1000 solution of corrosive sublimate or 1:10 solution of formalin, with the following pronounced results:
Effect of seed disinfection with either of the two disinfectants, especially with the corrosive sublimate solution, depends largely (beside the kind of seed, concentration of the disinfectant and time factors) on the (a) temperature of the disinfectant; (b) rinsing of the seed subsequent to treatment; and in some cases, (c) on the handling of the seed; that is, whether the seed were sown immediately after the treatment or allowed to dry up previously to sowing.
At a comparatively cool temperature, 60 to 70 F., all the tested seed could stand more prolonged treatment than at a higher temperature, 85 to 90 F. During the hot weather of last spring (1916), germination, and the initial rate of growth


of young lettuce and celery plants were injured to a great extent even by as short treatment as 10 minutes with 1:1000 solution of corrosive sublimate; the injury to watermelon and tomato was slight; the same treatment showed no injury or an insignificant one to eggplant, pepper, cucumber, and cantaloupe.
Drying up of the seed after treatment has been found in some instances to be injurious, especially in the case of seed of comparatively rapid germination; such as, lettuce and tomatoes. And finally, the extent of injury appears to be more or less decreased by prolongation of the rinsing subsequent to the treatment.
Formalin solution 1:10 has not been tried during the hot weather. During the winter time, even a 20-minute treatment at the room temperature, 60 to 70 F., was not, or very slightly, injurious to most of the seed tried, while 10 minutes was not injurious to germination of any of the seed tried (celery, lettuce, eggplant, tomatoes, pepper, cabbage, turnips, onion, cucumber, watermelon, cantaloupe, and beets).
From the few experiments so far made, it is too early to make any definite recommendation for disinfection of the seed. But this much is plain: First, that no seed disinfection experiments can be relied on if the temperature during the treatment and the subsequent handling is not sufficiently specified and considered; second, that certain recommendations for seed treatment, e. g., Soak the seed (celery) one-half hour or longer in warm, but not hot water, then soak one-half hour in corrosive sublimate 1 part to 1000 of water," may be good under certain conditions, but may be disastrous when used under conditions other than those under which the author of the recommendation worked out his method. The writer finds that at a room temperature of from 82 to 86 F. even 10 minutes treatment of celery in corrosive sublimate of the strength given, and with subsequent thoro rinsing of the seed and immediate sowing the process reduced the germination considerably (over 40 percent in one instance, as compared with the check) and also retarded the growth of plants that did germinate. And third, that at a temperature of 80 to 85 F. all the seed tried, excepting celery and lettuce, can be safely disinfected in 1:1000 solution of corrosive sublimate for 10 minutes if subsequently rinsed thoroly in several changes of fresh water or in running water immediately before sowing.


Fig. 13.Buckeye rot of tomato fruit, showing the zonated type which gives the appearance of a buckeye. Three-fifths natural size.
Buckeye Rot of Tomato Fruit Buckeye rot, a new disease of the tomato, at least one not previously mentioned in literature on tomato diseases, has been under the writer's study since January, 1915. It attacks only the fruit, on which it appears in the form of a grayish or pale
to dark greenish-brown, often distinctly zonate rot. (See fig. 13.)
The affected parts of the fruit are not bulged or sunken, but retain their normal shape. The consistency of the rot is about the same as tnat of the normal fruit, hard when the fruit is green and somewhat soft when mature.
The rot attacks the fruit only when it touches the ground or is very close to it. Because the fruit naturally has its blossom-end pointed toward the ground, the rot attacks it at this end, and for that reason, often appears as a peculiar form of the blossom-end. rot, for which it has sometimes been mistaken.
The disease is known among some tomato growers of the East Coast as water-logged fruit. The name is misleading and should not be used in connection with this disease. Some of the tomato buyers use the name buckeye for a rot of tomato fruit. Unfortunately the writer had no opportunity to learn directly just what is being called by this name. His indirect information leads him to believe that it is used for the rot under consideration here. As the name does describe very well a most striking appearance of the rot, that is, the frequently broad zonation of it, and as the name has never been used in reference to any other disease related to this, it is suggested here that the common name "buckeye" should be used in referring to the tomato fruit rot described here.
The buckeye rot was found first by the writer near Goulds, Fla., in January, 1915. Later in the same year the rot was found in practically every tomato field of the so-called "prairies" of that district (south of Miami) known as Redlands. In the early spring of 1916 the writer found the same rot on the West Coast near Bradentown and Palmetto.


Two specimens of tomato fruit affected with a rot and preserved in formalin for several years in our laboratory, showed on examination the presence of buckeye rot. One of the specimens came from Little River, Fla., 1911, and the other specimen had no label. This information shows that the disease is not a new one in Florida, and that it is of general occurrence on low land in South Florida.
This disease has not been described before, tho a somewhat similar disease of tomatoes was briefly reported from England.* It is also distinctly different from the rot of tomato fruit produced by the fungus (Phytophthora infestans) of the late blight of tomato and Irish potato.
The buckeye rot was observed by the writer to affect as much as 15 percent of the fruit in the field and 10 percent in transit and, tho the data as to the actual amount of damage caused by this disease in the State are as yet not available, it would be safe to say that it is of importance to the tomato industry.
Isolations of the causal organism, cultural work with it, and artificial inoculations carried out by the writer show definitely that the disease is caused by certain fungus of genus Phytophthora. The fungus seems as yet undescribed and should therefore be considered a new species. v
No direct experiments on control of the disease have been conducted. But because the rot attacks only the fruit which is close to or touches the ground, it seems reasonable to believe that staking the tomato plants will prevent the rot. As the rot affects the fruit in the field and spreads comparatively rapidly, it is also reasonable to believe that holding the picked fruit for a few days before packing it for shipment would enable packers to detect and discard all infected fruit, and guard against damage caused by the rot in transit.
A more detailed account of the study on buckeye rot is to be published in a special paper.
Some Bacterial Diseases of Vegetables black heart of' celery
This disease occurs more or less regularly each season and in practically every place where celery is grown on a commercial scale in Florida. The color of the rot is from a water-soaked
?Bancroft, C. K. The Brown Rot of Tomato. Jour. Bd. Agr. (London) 16, No. 13,. 1013, 1910.


and greenish-brown to blackish-brown. The number of plants affected with the disease in some fields this season, 1915-1916, was running up to 80 percent of the total number of plants, and the disease is considered by some growers as second to no other disease of celery in point of the damage it may do and its difficult control. Some celery growers believe that the disease depends very much, if not entirely, on the "health" of the host plant; too dry or too wet soil, or too much nitrogen in it, etc., is believed to result in a severe attack by the black heart.
Microscopic examinations and a certain amount of cultural work done with the affected plants lead to the belief that the trouble is due to certain bacteria, tho the writer has not yet found positive proof that this is true. Whether this disease is identical to some bacterial diseases of celery reported from various places, the writer cannot say now.
black heart of lettuce
This disease is due to certain bacteria and was reported by this Station on several previous occasions. (See Fla. Agr. Exp. Sta. Eept. 1908, lxxxvii, xcviii, pis. 4 & 5; 1912, xcviii-c; and 1913, lxxxvii and lxxxviii.) The disease did considerable damage this season in some sections of Florida. On several occasions bacteria identical with those described by H. S. Fawcett (Fla. Agr. Exp. Sta. Rept., 1908, lxxxiii) were isolated by the writer this season, but on account of other urgent work the organism was not sufficiently studied to obtain any additional information in this regard.
Other Diseases of Vegetables black spot and brown spot of tomato Black spot and rot, or rust", Phoma destructiva Plowr., and brown spot or rust", or nailhead rust", Alternaria solani (E & M) Jones & Grout.The black spot disease was generally prominent in Florida tomato fields during the period from August, 1914, until near the end of April, 1915 (See Fla. Agr. Exp. Sta. Rept., 1915, xcviii), while the brown spot disease was inconspicuous. According to reports the latter disease was the only one in evidence in May, 1915. It was commonly observed by the writer during the entire tomato growing season of 1916, when almost no black spot was found, tho the brown spot was quite conspicuous and caused considerable loss to the growers of early tomatoes on the West and East Coasts. The


attack of the brown spot this year was confined chiefly to the central and lower stems and to the lower and usually shaded fruits. The striking difference in prevalence of one or the other of the two diseases during the different seasons or different parts of the same season can be ascribed only to one of two factors, either to the difference in the temperature or to the difference in humidity.
The writer had observed abundant black (Phoma) spot of tomato on the Station grounds early in September, 1914, when the temperature was above 80 F. The same disease was found to be common in Redlands (South Florida on the East Coast) in January, when the temperature was never higher than 70 F. and sometimes down to 35 F. Very little of the brown (Alternaria) spot was found at the same season. Both seasons were wet. The brown spot was very common in May, 1915, and during the entire season of commercial tomato growing in 1916, that is, from January to June; the only factor that was the same during the two seasons was comparatively dry weather.
The foregoing observations lead me to conclude that the black spot and rot is a more conspicuous disease during more or less rainy weather, while the brown spot prevails during comparatively dry weather. The temperature within limits common for Florida seems to have very little or no relation to the prevalence of either of the two diseases.
Considering the mode of spore production and dissemination in these two organisms, one might have reached the same conclusion as to the effect of wet and dry weather on the extent of each of the two diseases, without having made the foregoing observations.
SOFT ROT OF PEPPER FRUIT
The first specimens of this rot came to the writer's observation early in July, 1915. On several occasions it was found to cause considerable damage to the fruit in the field. Isolations from the rotted fruit invariably gave only one organism, a white bacteria. By a number of inoculations made with pure cultures of the bacteria, by repeated re-isolations and re-infections, it was well established that the bacteria is the cause of the pepper rot, and that it can produce it only when the epidermis of the fruit is broken in some way. Inoculations of pure culture of the bacteria into tomato fruit, carrot and turnip roots, and potato tubers, resulted in the production of a soft rot much like


that caused by Bacillus caratavorus Jones. While but little cultural work has been done with the bacteria, it appears almost certain that it is identical with the latter organism.
BACTERIAL BLIGHT OF TOMATO AND POTATO
Bacterial blight of tomato and potato, Bacillus solanacearum Erw. Sm., was much in evidence this year practically all over the State and in places caused a great damage to the crops. A proper crop rotation, field sanitation and control of the sucking insects were recommended as precautions against the disease.
POWDERY MILDEW
Powdery mildew of garden beans, sweet peas and cowpeas, has been very common and often destructive to these crops. The effect of the mildew on the string-bean pod is rather peculiar and on account of its appearance the disease is known among growers in certain sections of the State as bean rust." Dusting with sulphur flour or flowers of sulphur has been recommended against the powdery mildew.
WHITE MOLD BLIGHT
White mold blight of garden beans and English peas, Sclero-tia libertiana Fckl., was destructive this year in some parts of South Florida. The fungus attacks all parts of the plants even those well above the ground. Field sanitation, with destruction of the affected plants and disinfection of the soil in and about the affected spots, was recommended to prevent a spread of the disease.
EGGPLANT FOOT ROT
Foot rot of eggplant, Phomopsis vexans (Sacc. & Syd.) Hart., was a very common and destructive disease in many parts of the State. The appearance of the disease is illustrated in fig. 14. The rot is usually dry, sometimes appearing in the form of a mere shrinking of the stem tissues at the infected region, sometimes in the form of a deep canker." A number of isolations gave the same fungus, P. vexans, the same organism which causes fruit rot, leaf spot, and stem blight, of the eggplant (See Harter, L. L. Fruit rot, leaf spot, and stem blight caused by Phomopsis vexans. Jour. Agr. Res. 2:331-338, 5 pi., 1914). Crop rotation, sterile soil for seed bed and seed disinfection were recommended as measures against the trouble.


Fig. 14.Foot rot of eggplant due to Phomopsis vexans (Sacc. & Lyd.) Hart. Natural size.
PINEAPPLE WILT
This disease, which seems to be working its way from the south (Miami district) to the north (Fort Pierce district), has been studied only on the East Coast. That is where the bulk of the crop is produced in Florida. From a commercial viewpoint it may be stated that only the Red Spanish variety is grown there. The work on pineapple wilt was started this year. Examination of many fields affected with the wilt and inquiry among the growers about the cause of the trouble did not lead to any definite idea of the probable cause.
The disease can attack plants very early in life, but is probably more severe in the third and latter years. Its appearance can hardly be described because the wilt" in this case does riot mean the same as in that of some other plants; the pineapple plant will remain rigid even when it is wilted." Pineapple plants affected with the wilt usually show a browning of the leaves with a peculiar spotting of darker and paler color all over their surface; the growth of the affected plants is more or less retarded or stopped; the root system is reduced or almost entirely rotted off. As a rule, the disease is much more in evidence in fields which were planted to pineapples before; new


fields commonly have no wilt, or only now and then a plant or small group of plants is affected. There are instances where some old fields are not showing much of the wilt while some new fields show as much as 15 percent or even more of it. Dry
weather seems to increase the wilt, while rainy weather may reduce it considerably.
According to the growers' opinion the following factors are the most important in development of the wilt: Planting the fields with slips taken from sickly plants; exhaustion of the variety and an attempt at rejuvenation by the introduction of plants from some other regions, Cuba for instance; lack of humus in the soil, and hence, grubbing under all of the old vegetable matter, a practice considered by some growers as very beneficial to the plants, while others consider it rather injurious ; and the mealy bug and red spider are considered by some as the forerunners of the wilt.
All these factors except, perhaps, the introduction of plants from other countries, provided they are not healthy plants, might have some effect on the development of the disease. Therefore, it was thought worth while to conduct some carefully planned experiments which would show whether or not any of these factors has any bearing on the disease. For this purpose the writer suggested the following plan to the local growers willing to cooperate in the work :
1. Six plots planted with slips taken from healthy plants, seven plots planted with slips from wilted plants. Each plot should contain at least 50 plants and be as narrow as practicable.
2. Six plots planted with slips from Cuba alternating with
Fig. 15.Pineapple trunk rot, evidently due to Thielaviopsis para-doxa (d. Seyn.) V HShn. Three-fourths natural size.


seven plots planted with slips from local fields. The plots should be as narrow as possible and each contain at least 50 plants.
3. Seven plots with the old pineapple plants grubbed under the soil before planting new slips, alternating with six plots on which the old pineapple plants were burned over or taken away. Each plot should contain five rows with at least 25 plants in each row.
4. Seven plots planted with slips treated* against mealy bug and red spider, alternating with six plots planted with slips not treated against the insects.
A number of growers were expected to carry out these experiments but only one, Mr. A. L. Hoofnagle of Fort Pierce did everything in the best way possible. He followed the suggestions almost to the letter, but experiment No. 2 was omitted because Cuban slips could not be obtained in sufficient number at the time the plots were planted (September, 1915).
The results of the experiments on Mr. Hoofnagle's place indicate, according to the reports at hand, that only the plots planted with slips from healthy plants show a distinctly better result (June, 1916) over the plots planted with slips from wilted plants. Other plots do not show any benefit for either of the other factors tested, which were; grubbing old vegetation vs. burning, and treating the slips against mealy bug and red spider vs. no treatment. In the latter case the treated plots appear to be even poorer than those planted with untreated slips, but this difference can be explained readily by the fact that the treatment was rather strong and injured many plants.
Later and more careful laboratory examinations of the roots of a considerable number of pineapple plants affected with the wilt which were received from various pineapple sections of the East Coast, showed in almost every case the presence of and more or less severe 'injury by nematodes. The nematodes in forms of unbroken fresh cysts and in masses of eggs, could be found embedded in the root tissues and cortex, but no great
*The treatment suggested was to soak the slips for one hour, or less, in a solution of 1 part of the stock whale oil soap and paraffin oil solution to 50 gallons of water. The stock solution being made of 1 gal. of whale soap, 2 gals, of paraffin oil 24 to 28 Baume, and 1 gal. of water. It was found later that one hour soaking killed buds in considerable number on the slips thus treated; half hour soaking left plants practically uninjured.


* Absence of the root-knot or rather inconspicuous development of it on pineapple roots, gives a probable explanation of why the nematode injury had been overlooked, or,-when found, considered- unimportant:*':
enlargements ("root-knots") were observed,* tho the young growing points of the roots when invaded by the nematodes showed a considerable increase in diameter, three to four times normal. These growing and invaded tips are soon killed and decay; and from one to many new side roots are produced just above the killed point. In general, a pineapple root system when affected with the nematodes will on examination disclose a decided root pruning. Small punctures or holes can be observed on old roots; these are the places where cysts were developed and later fell away thru decay of the surrounding tissue. Some manifestations of the presence and effect of the nematodes on the roots of pineapples are shown in fig. 16.
The injury by nematodes on many specimens is so evident in the form of a direct and severe pruning of the roots that there is very little doubt, even at this stage of the work, that the nematodes are often responsible for the pineapple wilt. The nematodes also may be responsible for introduction of certain other parasitic organisms. It is known that even when the nematodes are not the cause of certain diseases, they are one of the chief factors for making the host susceptible to it. Thus, according to L. P. Byers (letter) even varieties of cotton resistant to wilt are affected with the wilt if the cotton is infected with the nematodes.
The pineapple was known and reported as a host of the nematodes some time before the writer's observations, but the injury was considered "apparently not great." (See Bessey, E. A. Root knot and its control, U. S. Dept. Agr. B. P. Ind. Bui. 217:7-82, 3 Fig., 3 pi., 1911.)
A great number of isolations from the roots and trunks of plants affected with the wilt often yielded no fungus or bacterial organism at all. In many cases certain Fusaria (on the whole at least four different species of the genus were isolated from the pineapples) and a fungus which the writer has considered as Trichoderma, were quite often isolated, but neither of the organisms was associated with wilt constantly enough to suggest itself as a possible cause of it. A number of other fungi were isolated from diseased roots of pineapples, but each of the organisms occurred so seldom that they should not be considered at all in connection with the cause of the trouble. ,v>


Fig. 16.A, pineapple roots showing common forms of the effect of nematode infection; y, indicating the more prominent points. About normal size. B, a photomicrograph of root at point x (fig. 16, .4) showing two leaving nematode cysts exposed after the cortex has been removed.
Certain cases of apparent wilt" were found to be due to a decay of the pineapple trunk, evidently caused by the fungas, Thielaviopsis paradoxa (d. Seyn.) v. Hohn.; at least this fungus was isolated in pure cultures in each case (two samples, five plants in all) of the rot studied by the author. The rot is well illustrated by fig. 15. The wilt in this case is due, of course, to a more or less complete decay of the root-bearing


part of the plant and can be readily identified on the affected plants when pulled out.
The same Thielaviopsis was on several occasions isolated from a leaf spot of pineapples, a disease which had been reported from various other pineapple growing countries, but not from Florida.
Respectfully,
C. D. Sherbakoff, Associate Plant Pathologist.


REPORT OF THE LABORATORY ASSISTANT IN PLANT
PATHOLOGY
P. H. Rolfs, Director.
Sir: I submit the following report of the Laboratory Assistant in Plant Pathology for the year ending June 30, 1916.
Pecan Dieback
In the spring of 1914, plans were made for investigating a certain pecan disease, to determine its cause and nature, and to find a practical method for its control. This disease has been in evidence for some time and has caused considerable injury to pecan trees by killing the younger and less resistant ones. In older trees this disease kills back the younger shoots and later affects the larger limbs which ultimately die. (Fig. 17.) The results thus far obtained from observations and laboratory study as well as field experiments are that this disease (Die-back) of the pecan tree is induced by a fungus, Botryosphaeria berengeriana De Not., which infects young twigs of the pecan thruout the growing season, usually killing the distal ends. It causes older branches of the tree to die thruout the summer, due to a further advance of the fungus from the twigs infected
Fig. 17.Pecan dieback; tree seriously affected.


lOOi? Florida Agricultural Experiment Station
during former seasons. The fruiting bodies produced on the older branches are mostly perithecia, while those produced on the more recently infected twigs are mostly of the imperfect type, pycnidia, containing macro and microspores.
Fig. 18.Botryosphaeria berengeriana; section thru stroma.
Specimens of diseased pecan twigs were sent to Mrs. Flora W. Patterson for identification of the organism present in them and she stated in a letter that the fungus agrees sufficiently with Botryosphaeria bereyigeriana De Not. to be considered as that species.
ISOLATION OF MICROORGANISMS
During the spring and summer of 1914, a series of attempts was made to isolate the organisms which might be present in various parts of the diseased tree. Numerous petri-dish cultures were made from the inner bark and pith of the diseased and recently infected portions of affected twigs. These cultures gave several fungi, two of which were found to be present more or less constantly. These two forms were transferred to culture tubes containing sterile bean-pod plugs, also to tubes containing sterile oak-twig plugs, pecan-twig plugs and orange-twig plugs, as well as various agar media. One form was soon recognized as a species of Phomopsis; the other produced at first a grayish, later an olivaceous gray, and lastly dark or nearly black mycelium with woolly sclerotic bodies but apparently did not produce any fruiting bodies.
A second series of cultures was made from single ascospores taken from the perithecia found on diseased pecan limbs. A small portion of the bark containing several perithecia was placed in a drop of sterilized water in the bottom of a sterile