Experiments on the supposed deterioration of varieties of vegetables in Porto Rico, with suggestions for seed preservation

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Material Information

Title:
Experiments on the supposed deterioration of varieties of vegetables in Porto Rico, with suggestions for seed preservation
Series Title:
Bulletin / Porto Rico Agricultural Experiment Station ;
Physical Description:
30 p. : ill. ; 24 cm.
Language:
English
Creator:
Kinman, C. F ( Charles Franklin ), b. 1880
McClelland, T. B ( Thomas Brown ), 1886-
Publisher:
Porto Rico Agricultural Experiment Station
Place of Publication:
Mayagüez, P.R
Publication Date:

Subjects

Subjects / Keywords:
Vegetables -- Seeds -- Puerto Rico   ( lcsh )
Plant genetics   ( lcsh )
Genre:
government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )

Notes

Bibliography:
Includes bibliographical references.
Statement of Responsibility:
by C.F. Kinman and T.B. McClelland.

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 020042399
oclc - 21269725
System ID:
AA00014644:00001


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Issed November 8, 1916.

PRTO RICO AGRICULTURAL EXPERIMENT STATION,
D. W. MAY, Agronomist in Charge,
Mayaguez, P. R.


Bulletin No. 20.




ERIMEIENTS ON THE SUPPOSED DETERIORATION

S. VARIETIES OF VEGETABLES IN PORTO RICO,

WITH SUGGESTIONS FOR SEED

PRESERVATION



BY"


C. F. KNMAN,
Horticulturist,
.. AND

.I4 T. B. McCLELLAND,
Assistant Horticulturist.






UNDER THE SUPERVISION OF
STATES RELATIONS SERVICE,
Office of Experiment Stations,
U. S. DEPARTMENT OF AGRICULTURE.






WASHINGTON:
GOVERNMENT PRINTING OFFICE.
S:'ts
STATS REATIOS SEVICE























PORTO RICO AGRICULTURAL EXPERLIKENT SSTT

[Under the supervision of A. C. TRUE, Director of the States Relatons Bervice, United 8thttp
of Agiculture.]

B. W. ALLEN.- Cfof Offi of Expermeni Swdo
WALTER 1-. EVANS; Chief of Diis of Insular igtto, Ofi of B,~ 4-

STATION STAFF.
D. W. M-&Y. Agrnwomist in Charge.
P. L. Gum Chemist.
C. F. KxmxAN, Bforticulturist.
R. H.- VAN ZwALUW1Mijsons, Entomologist.
E. W. BR&'NDES, ln atooit
T. B. McCCLEMAND, Awst~ant Horticulturist.
J. 0. CARURERO0- Am8otant Cheisti8..
to. ALEMxAR. Jr., Clerk.
(2).






r 53548



LETTER OF TRANSMITTAL.


PORTO RICO AGRICULTURAL EXPERIMENT STATION,
Mayaguez, P. R., Octobei 19, 1915.
S SI: I have the honor to submit herewith a manuscript on Some
E experimentss on the Supposed Deterioration of Varieties of Vegetables
;in Porto Rico, with Suggestions for Seed Preservation, by C. F. Kinman,
iiortiulturist, and T. B. McClelland, assistant horticulturist.
SThis paper gives the results of several years' study on the question
i"of the supposed deterioration of varieties of vegetables when grown
i: through several generations in the Tropics. The information con-
I9:tained herein should be of great benefit, not only in Porto Rico, but
::throughout the Tropics generally,. or wherever similar conditions
!exist. In connection with these investigations it was found that the
* season of planting affected the yield and character of vegetables to
a remarkable degree. The data presented will, it is believed, go far
toward developing vegetable growing, an industry that is greatly
neglected in Porto Rico.
Vegetable seeds of all kinds deteriorate rapidly in the hot, moist
atmosphere of the Tropics, and a method has been developed whereby
ithe viability of seed can be retained for a much longer period than is
S-possible under normal conditions. This information will doubtless
prove valuable to seedsmen and planters generally.
I respectfully recommend that the manuscript be published as
Bulletin No. 20 of this station.
Respectfully,
D. W. MAY,
Agronomist in Charge.
Dr. A. C. TRUE
Director States Relations Service,
U. S. Department of Agriculture, Washington, D. C.
Recommended for publication.
A. C. TRUE, Director.
Publication authorized.
D. F. HOUSTON,
I Secretary of Agriculture.


















CONTENTS.


Introduction .. ...................... .................. ....
Practices followed in the experiments. ---------- I......
R records of the crops ------------- ------------- -------------
B eans. .. -------------.. .. .
O k ra -- -- -- -- -- -- --- -- -- -- -- ---- ...... .
T om atoes.. --- -- -- --- -- -- -- --- --- -- ----- ----- ----
L ettuce ------------- ------------.. ... ..
Preserving the viability of vegetable seed -_------- --------_---
sum m ary -------------------------------------- ---------




ILLUSTRA-TIONS.


FIG. 1. Monthly rainfall at Mayaguez, P. R., for the years 1910 to 1914-
2, Average yiekds of bean generations ---------------- I------------
3. Yiedsl of dlifferent bean generations as affected by plantingeason
4. Q ura -yield as affected by planting season. --------.... .
5. Average yields of okra generations. ... .........................
6. Average yields of Royal Red tomato generations ............-------
7. Average -yields of Royal Red tomato generations, showing saoa
variations ... ...... ... .'..; ..... .. ... ..... .... ... ........ .. .
8. Air-tight jar illustrating method of preserving seed aver calcium cdrd
9. Results of germination tests of seed ------------------------------
10 os fvibltyo ipredvgtal ee'xpw o h pe a

11.Lsso iaiiy fhmegon eeabesedepse oheoe a',











EXPERIMENTS ON THE SUPPOSED DETERIORA-
TION OF VARIETIES OF VEGETABLES IN PORTO
RICO, WITH SUGGESTIONS FOR SEED PRESER-
VATION. __

INTRODUCTION.

Vegetable gardening in Porto Rico is a small industry and one in
which there has been little progress for many years. Aside from the
culture of tomatoes, okra, beans, pigeon peas, and starchy root crops,
Which are grown as horticultural crops, the farm garden is seldom
seen. The commercial gardens are few and small and devoted to the
culture of few vegetables, these often of inferior type. The poor
development of the vegetable industry results from the unfavorable
soil and climatic conditions, a lack of knowledge regarding the value
of the best varieties and concerning good seed and its storage, and the
| production of seed at home. There is a belief that northern-grown
vegetables degenerate quickly in Porto Rico and that the seed from
even the first generation produces plants which are inferior to their
Parents. This belief results partly from the common practices in
Z vegetable growing. On account of the heavy summer rains, the
crops which are grown from seed are for the most part planted in the
I fall or winter. If seed harvested from these plantings is immediately
Ssown, the plants as a rule give poor results, as they must contend with
heavy rains, intense heat, and other unfavorable conditions. The
unsatisfactory development and yield of the plants are naturally but
unfairly attributed to the rapid degeneration of the seed resulting
from the effect of the tropical climate.
Because of the high humidity, seed deteriorates rapidly in the
Tropics if exposed to the open air, and, therefore, much of the seed
offered for sale by local dealers is almost valueless. Imported seed
is often several months old when it arrives here, and it soon loses its
viability, leaving the home product to supply the demand. The
defective methods employed in collecting, curing, and storing seed
render much of the seed harvested in winter useless for planting
the following winter, and seed produced during the rainy season,
k when seed production is very low, often must supply the demand.
In 1910 experiments were undertaken to determine the degenerat-
ing influence of the climate of Porto Rico on the growth and produc-
(5)
HE .t. :
C '::, .
=..:.H...= .








progress of the work, observations hae also been
seasonal effects on the produc-tiono different plants, .
stori~ng seed, and tests made to asetain the period of
seed imported from the Nor'th and- of ed grown in'Porto R"M
results of this work should prove valable, in changing, the
belief and practices which have prqically stopped prgr8 m
ture of some vegetables.

PRACTICES FOLLOWED -THE EXPERIMENTS
In undertaking this work seed of a nmber of common garden
tables, including tomato, popper, oka, beans, lettu-ce, radish,
41
squash, and cantaloup, which ha been grown in the North,
imported. When the seed first arrvd, a portion of it was pl
closed jars which were kept dry by plaing mi the bottom a few
of calcium chlorid. (Se'e fig 8, p.27. Tho seed treated in this wa$
mained in first-class condition unti the experiment was conq1u,
or .until the seed was exhausted by pan ting or testing otherwise
Throughout the experiment, the crps were grown inthe opepL
under normal field conditions, an ona site 'very similar toW
employed for gardens in the viciniy This field is in an almost
valley where the soil is a heavy dx loam which is fairl fertile,
has little vegetable matter and pooasbdrainage. To avoid d,
from surface moisture and to insur soil. aeration, the land was
stirred, and raised beds with a spc of 1 foot between thenz,
made just previous to each planting As plantings of each succeed
crop could not he made in the sam place, there was danger of. min
encing the yield by soil variation betwen the different plats,'altho
all the land used for- the experimental apparently very uniform.
overcome as much as possible any ovation in the soil fertility, a hew
and uniform application of fertile w as given each crop. Theft
tilizer contained 3 per cent nitrogen 9 per cent phosphoric acid-,
10 per cent potash. It was applied at rate slightly in excess of I
per acre. In addition, a unif orm. during of stable manure was "Is
the beds. The nitrogen min the form of nitrate of soda was app
after the plants were well establishd The quantity of fertilizer
intended to be in excess of the ned of the plants so as to prev
minor differences in the natural soi fetility of the differeaA plats in'
encing the growth of the'. plants. This. would make the
responsible for the growth and produtveness of the plants of df
generations. As the imported seed ad seed from succeedi'ng-g
tions were plan ted in beds which wer side by side, the variati
solcniioscudhvehdltleifuneonteyed







-:,In order to eliminate as far as possible the factor of varying weather
ioinditions, simultaneous plantings were made of as many different
iienierations as possible.
: Care was taken that the crops should not degenerate nor be
Improved by seed or plant selection or by crossing with other varieties.
f At the time of planting a much larger number of seed was sown than
Sthe number of plants desired for the experiment. The young seed-
lings were later thinned, leaving the desired number of plants of
average size and vigor. Where there was danger of blossoms being
fertilized from other varieties, the blossoms which were to produce
seed for future plantings were hand-pollinated and bagged.
The term season in this discussion is used with reference to periods
of rain and drought, as the temperature in Porto Rico varies by only
a few degrees throughout the year and is always conducive to the
growth of vegetation. The seasons of rain and drought and the ram-
Sfall for the different months during which the experiments herein con-
i sidered were in progress are shown graphically in figure 1. By com-
I paring the rainfall and the production of the crops included in this
experiment it will be seen that the variation in the amount of rainfall
Sin different months is probably responsible for much of the variation
S.. in yield between different times of the year and therefore must be
considered in calculating the results of the harvests. As the rainfall
varies considerably in different localities in Porto Rico, the results
I secured with reference to the effect of climate on the production of
vegetables are applicable to sections where the distribution of rain-
:; fall throughout the year is similar to that at Mayaguez.
S The results which were obtained during the few years' work with
Vegetables are given below in detail.
In order that the system of naming may be understood, a word
of explanation is necessary. Each planting of northern-grown seed
is denoted by a Spanish ordinal number, as Primera, Segunda, Ter-
cera, indicating the first, second, and third plantings, followed by
1st, indicating first generation or northern seed. In each instance
the plants raised from seed of these plantings bear the same Spanish
ordinal as the parent planting, followed by 2d, indicating the genera-
tion, and so forth, lineal generations being always denoted by the
same Spanish ordinal. In some instances several plantings other
than first generations were made from the same lot of seed. These
are distinguished by letters following the English ordinal.

RECORDS OF THE CROPS.
After the work had been in progress for only a short time it was
seen that a few of the vegetables included in the experiment were not
Suited to the work, as climatic and soil conditions were not favorable






















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*. ...... ...; .. *..... .. .. R :: < 5; : :




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i :. seed production. Cantaloups and squash were not grown after
ii first season on account of troublesome insects and weather con-
i|tions, which cause a very poor yield and would probably influence
I '|results by the necessity of planting, at least from later generations,
seed which was not from average and representative plants and fruits.
SBeets and radishes were not grown beyond the first generation, as
I attempts to produce seed failed. The leaves and roots made a thrifty
| growth, but tfie plants all died without sending up seed stalks. While
These plants occasionally produce seed in Porto Rico, the crop is so
iI uncertain and the yield so small that for the present at least it is
Necessary to import the seed required for these crops.
With peppers the Ruby King variety was planted, but it was impos-
*- sible to get data of size and weight of fruits, as they were nearly all
attacked by rot before they matured. The plants grew poorly and
produced such a small crop, as compared with the kinds commonly
| grown throughout the island, that it was apparent that seed of this
Stype of peppers should not be imported. Further tests were made,
however, to compare the growth and yield of the types commonly
grown in Porto Rico with those of a number of similar imported
Varieties, including Ruby King, Chinese Giant, and Tabasco, to
determine the advisability of producing seed from them. Plantings
i of these varieties were made in the spring when the weather favored
w a good plant growth, but later the rainfall was so heavy that con-
Sditions were unfavorable for growth and blossoming. The imported
i varieties made a rapid growth at first, but before fruit matured, the
| leaves began to fall, and the plants became barren stalks which did
Snot regain their vigor. The average production per plant of Ruby
SKing and Chinese Giant was between three and four marketable
Fruits, and that of Tabasco was small also. The growth of all the
common Porto Rican types was vigorous from the first, and they
continued thrifty and productive for several weeks after the northern
varieties were dead, their average production being over 16 fruits
per plant. The fruit from the common Porto Rican type resembled
very closely in size and shape the best northern kinds and was not
inferior to them in flavor. The types tested included both sweet and
pungent varieties.
As the ancestors of the seed imported from the North for this test
were doubtless taken from tropical America many years ago, these
results show that the marked change effected by acclimatization and
selection to suit northern conditions resulted in rendering them unfit
Sfor tropical conditions. Results with other crops discussed here show
That where seed or plant selection is not practiced the place effect on
These crops is too slow to be of importance to gardeners.
S 598360-Bull. 20-16--2
I-:.,;.









































Date of planting.


Porte Rico plantings.
Mar. 12, 1910.........
Sept. 17, 1910........
Dec. 24;1910-.........
Mar. 11, 1911..........
Sept. 16, 1911........
Do...............
Do..............
Dec. 22, 1911... ......
Do ..............
Do...............
Mar. 12, 1912..........
Do..............
Do..............
Jan. 17, 1913..........
Do ..............
Do ..............
Do...............
Nov. 8, 1913.........
Do...............
Do..............
Do...............
Do...............
Do...........
Do..............
Do..............
Mar. 26, 1914..........
Do...............
Do...............
Do.............
"Do..............
Do..............
Do..............
Do...............
Do..............
Do..............


Minnesota plantings.

June 1, 1912...........
Do..............
SDo..............


Name.


Primera 1st......
Primera 2d........
Primera 3d........
Primera 4th.......
Segunda 1st......
Teroera 1st.......
'rimera 5th.......
Cuarta 1st........
Tercera 2d.......
Primers 6th......
Quinta 1st .......
Cuarta 2d.........
Primera 7th.......
Octava 1st.......
Minn. A 1st.......
Minn. B 1st.......
Minn. C 1st......
Novena 1st.......
'Decima 1st.......
Quinta 2d B......
Octava 2d........
Minn. A 2d.......
Minn. B 2d.....
Minn. C 2d........
Primera 8th B....
Undecims 1st....
Dnodeclma 1st....
Novena2d........
Decima 2d .......
Quinta 3d.......
Octava' 3d-......
Minn. A 3d........
Minn. B 3d........
Minn. C Sd.......
Primera 9th.......


Sexts 1st..........
Quinta 2d A......
Primera 8th A.....


Number
of pro-
ducing
plants.


-Number
of days
from
planting
until
blossom-
ing.


Average
number
of pods
per
plant.


I I. I crii"


137
61
137
126
112
127
124
148
131
138
127
135
131
127
116
103
119
86
117
57
73
88
84
88
95
53
73
84
95
71
77
79
71
90
79


32
31
35
37
30
30
31
36
36
36
32
34
34
34
34
34
35
35
34
35
35
34
34
35
35
32
32
32
32
32
32
32
32
32
32


9.31
S3.02
* 6.03
5.97
4.22
4.48
4.99
3.57
2.88
3.91
11.17
10.78
11.99
5.10
6.12
5.12
5.17
2.73
2.26
2.79
1.86
2.19
2.11
2.01
2.22
11.89
10.21
8.64
8.58
9.51
9.10
8.14
9.80
9.30
9.22


14.67
12.10
12.79


Average
oumbeas
p ,bgab;


3.84
2.64
2.78
2.24
2.41
6IS1
2.20
2.13
1.97
2.19
3.21
3.18
3.21
2.60
2.78
2.56
2.64
2.02
2.01
. S
1.91
1.84
1.67
2.10
2.98
g.mo

3.28
3.01
2.52
3.05
3.0
3.15
3.18


3.41
3.41
3.41


l ...; i .
Vtbm;e

pet'


H..
1 .. ... .
1634
ILS ii

11.7

"8.6;. .
.7.

34.3
38.5 :
1la
17.0 ::



4.4


3 L..4 ..
5.8....
4f.2 a

4 .- ..

Nl'i






i. .:
W1.


1 Estimated.


I .


.. :. ...


..........
..........
..........


..ii...
...ii






The first planting of beans, Primera 1st generation, was made
Marc::" h 12, 1910. The season was quite favorable for this crop, and
; the yield per plant averaged 9.31 pods of 3.34 beans each, or 31.1
Beans per plant.
From this crop two plantings were made during the following
June. The first, made on June 11, was removed on account of injury
From an insecticide. The second, planted on June 25, was almost
completely destroyed by anthracnose and very wet weather, so that
From 135 plants only 6 pods were picked. As these plantings were
complete failures, they are not included in the table of bean genera-
tions.
A third planting of Primera 2d generation was made September
17. Even though the season was much drier than usual, with weather
conditions seemingly exceptionally favorable, the plants were badly
diseased and did not fully develop their seed, many being obtained
in the yield which were not sufficiently developed for either eating
Sor planting. The producing plants gave an average yield of only
eight beans per plant, showing a marked falling off in number of
Both pods per plant and beans per pod.
Primera 3d generation planted December 24, gave a yield which
more than doubled that of the parent generation, but it still amounted
to little more than half of the yield of the original planting.
The planting of Primera 4th generation was made March 11, 1911,
a year later than the original planting. The yield amounted to less
than half that of Primera 1st generation. In the light of further
tests it is assumed that this planting fell below the usual production
iof plantings at this season because the amount of moisture was below
the optimum, the rainfall for March, May, and June of 1911 being
Less than that for these months in any other year during the term
of the experiments.
As the original seed had been kept in the drier, some new seed,
Segunda 1st, of the same variety, was obtained from the same seed
house and planted simultaneously with seed of the original lot,
Tercera 1st and Primera 5th, seed from the fourth generation. Fresh
seed was procured for comparison with seed kept in the drier, since
the seed for Primera 5th generation was quite fresh and could not be
strictly compared with the old dried seed without a check on the
latter. This planting was made September 16, 1911, and had to
'i contend with very wet weather. There were 37 days with rain, 29.39
Inches of which fell between planting and the first picking. The
development of many pods and beans was stopped at an early stage
Sby wet weather and disease fostered by such weather.
The differences in average yield per plant of beans of sufficient
Development to be counted were so slight as to fail to show any
degeneration, since the fifth generation yielded 0.4 bean more per
I n.









#IF
plant than one first, gnrwwio Aiid ei
other. 'Since the old seed kept in the dtrie ot
crpthan th6 fresh seed, the intense dyn a
number of beaus per pod -in the two first generations- vii



4
In the fifth generation it: was less than 'in th fist Vw,
balanced by the -greater number of pods per plant.
The next planting, which was made on IDecember 2,2, 149
sisted of a first a second, aind a sixth generation. Inee
the preceding weather, the rainfall was entirely too sniAll
crop, there. being 'but si 'days, with -rain and the total
amounting to only 1.68 inches from planting until the first
mature beans. As -in the preceding case, the advanced
gave the greater average number of pods per plant. The,
Primera 6th generation averaged also a slightly greater
-beans than its contemporaries, w which is in contrast with the
of Primera 5th. The second generation showed the smallest
number of pods per plant and beans per pod. The size of t
of the second generation was also below that-of its, contemp
The next planting -was, made Murch 12)' 191:2. Itco
fisa second, and a seventh generation. In -no other Porto,
planting did the average yield of beans per plant for any
haever eqa h veaeyd of this entire planting.
vanced generation, Primera 7th, led with an average pro
38.5 beans per plant. This was followed by Qjuinta let g,
with 35.9, and Cuarta, 2d generation with 34.3 beans. Here it iis
that the. order- corresponds with that of the. preceding planting ;
advanced generation ina the lead, followed by the: 1st, and Iptl
the 2d generation.
In order to observe any evidence of changes which had been)
dluced in this -crop by being grown in the Tropics -for from o
several generations, it was decided to make several plantings iiin
North. For this purpose seed were sent to Minnesota.Thog
courtesy of Dr., J. N. Tate, of the Minnesota School for the',
plantings were made June 1, 1912, at Fari-bault, Minn., of Sexg
generation, being seed of the original lot kept over oalciumck
of Quinta, 2d generation A, and -of Primera 8th generiation A..]
beds were made Side by side. under very uniform conditions Of
and light. The soil was a friable, rich, black loama, now wel
but having formerly been swamp land. All received the same
menty all blossomed about the same time, and all were picked-
same date. All made a strong, vigorous growth and were muc
and more luxuriant than any plantings in Porto Rico*, The
were thrifty and vigorous, those whose antecedents had been i
for seven generations in the Tropics showed -a little less p
vio hnteote wbtee wihn isicincudb






ii ? .13

.The average number of beans per pod was identical for all-that is,
.41. In number of pods per plant the 1st generation, plants whose
7 forbears had never been grown in the Tropics to our knowledge led,
;, followed by the 8th generation, and lastly the 2d generation. In
yield of beans, the average crop per plant ran 50, 43.6, and 41.2
beans, respectively, yields never equaled in any of the Porto Rican
plantings.
Though a counting of the number of beans of the original lot which
would be contained in one-half liter was never made, new seed re-
ceived from the North January, 1913, ran 1,103 beans. Those grown
in Minnesota ranged from 1,009 to 1,111. It may be assumed from
these four counts of northern-grown seed of this variety that the
original lot of northern-grown seed ran somewhat the same. The
seed harvested from Primera 7th generation ran 1,226, and from
Quinta Ist, 1,268, beans to the half liter. These Porto Rican grown
seed, then, were considerably smaller than the northern-grown seed,
Sand this in itself might account for the larger crop from Sexta Ist.1
The next planting in Porto Rico was made January 17, 1913. It
L consisted of four 1st generations in that the parent generation of each
.had been grown in the North. Octava 1st was from new seed just
Received from the North; the other three were from the Minnesota
crops of the previous summer, Minn. A 1st from Sexta Ist, Minn. B
: 1st from Quinta 2d A, and Minn. C 1st from Primera 8th A. Minn. A
I1st produced an average of 17 beans per plant, while the others ranged
from 13.1 te 13.6 beans. It is thought that perhaps Minn. A 1st was
Sin a slightly moister location than its contemporaries, as no other
explanation for this difference can be seen.
The next. planting was made November 8, 1913. As a whole, it
Save a lower average than any other lot of plantings. It consisted of
.a two 1st generations, five 2d generations, and one 8th generation.
SThe average yield of the two 1st generations was 5 beans, of the five
S2d generations, 4.1 beans, and of the 8th generation, 4.7 beans per
plant. The 2d generation average yields ranged from 3.3 to 5.8
beans per plant, including thus the smallest and the largest average
e yield. Such yields show the very marked seasonal effect, but little
else. It is interesting here to compare the yields of two plantings
made from the same lot of seed, Quinta 2d A, planted in Minnesota
and yielding an average of 41.2 beans per plant, and Quinta 2d B,
M;A planted in Porto Rico and yielding 5.8 beans per plant.
The final planting was made March 26, 1914. It consisted of two
1st generations, two 2d generations, five 3d generations, and one
j 9th generation. The number of plants in all rows was somewhat
: reduced by a Sclerotium blight. Except for this, conditions were
1 See Vermont Sta. Bul. 177 (1914).































pro uc i i wr in i In th 1
J .... ..:.

Fm r w W sdn nm rrn e Mc 2w ffi 22iSW-wo
FIG. 2.-Average yieldspf bean generations, the number of beans per plant being indicated by .iaSi
with lineal generations connected by dotted lines. The appended dates are those OfM
4. In the next planting of a 1st, a 2d, and a 6th generation, 0.:i
productive plants were included in each. In the Novembe-r, I:
planting these plants ranged from 2 to 5 in the 1st generation,
from 2 to 26 in the 2d generation, with 20 in the 8th genera
Though these tests did not afford sufficient data for a system=
classification of this tendency, fiore of such plants were observ
the fall plantings than in plantings made at other seasons. *
Two diagrams are appended in order that the results of these: A
ings may be clearly shown. In figure 2, the yields of thyi
generations are shown, and it is seen that the only uniformityiadid
is a large yield at certain seasons and a poor yield at others. NoX
cautions of degeneration are seen. In the other diagram, figr
points determining the curve of the 1st generation were obtaE
taking an average of all Ist-generation plantings made in
month. These points were then connected by lines, thus fo
curve showing the yields of Ist-generation plantings as
seasons. The yields of the 2d and 3d generations are showni





15

I:: Sane way. Of each of the more advanced generations only a single
I::planting was made. These are-indicated by crosses. This indicates
i: ery early the main factor governing the yield.
In considering the many plantings that have been made, it is seen
:that the matter of a large yield or a small yield of this particular crop
is not influenced by the progenitors having been previously grown in
Sthe Tropics for a long time or a short time or not at all, but is chiefly
Sa matter of the planting being made at the proper season. At certain





40 -
36
















FIG. 3.-Yields of different bean generations as affected by planting season.
seasons ah plantings gave a poor yield, at other seasons all produced
excellent crops.
OKRA.
In the work with okra the White Velvet variety only was planted.
The seed used here was grown in Georgia and was sent to Porto Rico
by J. M. Thorburn & Co., of New York City. The plantings of okra
were made in the field in beds which were all 25 feet long, except
those for the 1911 plantings, which were 32 feet long. These beds
were prepared in the same manner as for other crops. The seed was
alwayss planted thickly, and the seedlin-s were later thinned to 1 foot
&part. In order to secure records of yields of mature pods and of the
number of seeds per pod, and to obtain seed for future generations,
^jii'" excellent crops.


;The seed used here was grown in Georgia and was sent to Porto Rico
I: by S. M. Thorburn & Co., of New York City. The plantings of okra
|| were made in the field in beds which were all 25 feet long, except

were prepared in the same manner as for other crops. The seed was
; always planted thickly, and the seedlings were later thinned to 1 foot
j. apart. In order to secure records of yields of mature pods and of the
|||; number of seeds per pod, and to obtain seed for future generations,











































Date of planting.


Name.


I- -I I _


Mar. 12, 1910.....
July 16, 1910......
Dec. 12,1910.....
Mar. 11, 1911.....
Do.........
June 10, 1911....
Do.-........
Jan. 22,1912. ....
Do...........
Do.........-
Mar. 12,1912.....
Do.........
May 13, 1912.....
Do..........
Jan. 4,1913.......
Do..........
Do.........
Do..-.-......
Do...........
Nov. 8, 1913......
Do..........
Do ..........
Do..........
Do.--........

Mar. 26,1914...
Do...........
Do..........
Do...........
Do.........
Do.--........
Do..........


Primera 1st.......
Primera 2d........
Primera 3d A ----.
Tercera 1st........
Primera 3d B..- -
Cuarta lst....-..--
PriWoa 4th......
Quin tIst......
Cuarta 2d A.......
Primera5th A ....
Tercea Sd........
Primers 5th B....
Cuarta 2d B-......
Primera 5th C....
Sexta st .........
Quinta 2d.........
Teroera 8d......--
Cuarta d-.........
Primer 6th A....
Septima 1st......-
Seta 2d.........
Quinta 3d........
Teroera 4th........
Primera th B....
Primera 7th A...
Octava lst........
SeptimaS d......
Sexta 3d.........
Quinta 4th.......
Tereera 5th.......
Primera 7th B...
Primers 8th......


.... -.. .
SPlants which maturedseed were left only 166 days.


In the plantings made during the following years, two:6
generations were planted side by side on the same date, so ti.i

would be no differences in development of the different gi.

due to weather conditions. In 1911, two crops were g
.. .*..::; i::::, :


.. ..* ...


Aver-
age
num-
ber of
mar-
ket-
able
pods

plat.


Num-
ber of
days
cov-
ered.


Aver-
age
-num-
ber of
ma-
ture
pods
pErt


A Ver-
age
length
of ma-
tpre
pods.


Aver-
age
n lm-
bar of
aod
per
pod.


age-


whic

pods
we
Cut


p I


..i.i..



Inches.






e. ie
5.99
6.O4
6.9
.. ..o..






6...4
Il*ll*i

.i...Iil
...l...
......ll
i.....li


203
206
222
1240
1240
171
171
235
235-
235
200
200
138
138
241
241
241
241
241
146
146
146
146
146
146
187
187
187
187
187
187
187


...i-:.



a-..- .a
. ....,..
...V.*.



i---as


140.8
50.1
120.0
97. 4
77.8
45.1
44.4
126.2
162.0
114.6
86.4
82.0
31.1
2.3
155. 7
122.6
127.8
112.0
124.8
41.7
49.9
43.6
67.2
58.3
54.9
74.0.
51.7
62.9
68.5
71.8
60.6
67.6


20.3
6. 6
16.3
18.0
10.3
8.0
8.4
12.2
15. 8
11.3
29.9
17.1
7.8
5.0
14.4
18 3
23.6
19.4
14.1
13. 5
12.3
9.4
13.4
17.2
10.9
17. 3
17.6
12. 1
10.4
17.9
11.7
13.6


74.6
6.2
36.5
68.5
63.9
67.2
56.1
60.7
59.3
73.8
67.9
74.9
64.7,
54.7
52.1
51.4
60.9
53.0
50.5
55.8
48.5
61.1
48.7
.654.7
71.0
60.9
64.6
67.
68. 7
707


inch".
IL1

61. 4
38.8
78. 4
73.4


100.7
51.7

67.fi
76.4
S62.
74.1
64. 3
71.6
56.6
62.6
89.5
50.6
.3, a

40.9


"81.8
,86.6
79i5
87.1.
78.2
77.8


46.8

14.1
38.3
5K 3
50.4
ai;4
26.4
as&



319.
t.

2L. 4
28

a:K
a83

Mit.0


, I l 1 ... --.! r .








.17

$d generation planted in March, and a 1st and a 4th generation
tedin June. The plantings made on the latter date produced a
uniform growth and gave a yield which was almost identical for
ithe two generations, but the earlier crop shows a greater plant growth
iad a heavier yield from the imported seed. In two of the three
Slater crops in which the 1st and the 3d generations were grown simul-
Straneously, the yield of green pods of the 1st generation was higher
than that of the 3d, and in two cases the same was true of the yield
-of mature pods, while in one case the third generation bore more
than the first. In the plantings of January, 1912, March, 1912, and
May, 1912, the growth of the plants and the yields were higher for
SE :the 2d than for the 5th generations, bui these results were not in
A .accord with other plantings. "A notable result will be seen in the
yield of three plantings of Primera 5th generation made in 1912.
i The first of these three plantings was made on January 22, the second
S. on March 12, and the third on May 13. The yield of marketable
| pods per plant was 114.6, 82, and 28.3 respectively. These results
Show the marked effect of climatic conditions and the importance
Sof testing degeneration by comparison of plantings made simulta-
.neously. In the last three crops of the experiment, one planted in
SJanuary, one in November, and one in March, five, six, and seven
Plantings respectively were made simultaneously. These plats gave
excellent opportunity to observe the effect of climatic conditions on
okra when grown in Porto Rico for a long or short period. Aside
From the relative production of green pods, only minor differences
i were found in any of the details under observation for the different
Generations planted at the same time. The production of green pods
; in the row planted to the imported seed was markedly heavier than
that of later generations in two of the three trials, and lower in the
other. The growth and general appearance of the plants of the
. different generations were very uniform.
Where a number of generations were planted simultaneously, the
; central rows of the plat were planted to imported seed, to seed of
i: the 2d, and to the most advanced generations. Where a number of
rows were planted, the possible variation existing in soil condition
between different sections of the plat was probably responsible for
the small differences in yield of the various generations, as the differ-
ences are not consistent and follow no line of advance or decline.
SThe results obtained in the five years' work with okra, during which
| 32 plantings were made at 11 different dates, reaching finally the 8th
generation, indicate that with this crop there has been no degenera-
tion resulting from the climatic or soil conditions in Porto Rico, and
E t that the hoine-grown seed from advanced generations is as valuable
for planting as the northern-grown seed.
==:..:.



































































Honor Bright. These will be discussed separately.
Royal Red.-The seed of Royal Red tomatoes was from th. i
gressional seed distribution of 1909 and had been grown the
'":,, ",... *:.. : .. ..
..... : : : .: :: i:..*". ..... .





I!'


19


Sf California. That for the later plantings was preserved over cal-
Scdum chlorid, so that only seed derived from this one lot was used.
The seed was planted in flats or pots, and 1I to 13 days later, the
Seedlings were transplanted to small individual pots. From 24 to 29
- days after sowing 13 plants were set in the field 2 feet apart in the
row. In several instances this number was reduced through insects

or disease. The plants were staked, but usually left unpruned. In
recording yields, tomatoes weighing 25 grams or less were not


I

I


I


-i


a --------------------------------------




i ^ \ j \ I \

.-, ----- -.-


.* n o ; *iy
"- 'F "---4 "- -
Iwo w*
-.--~ ~ ~ ~i-. -- ------------ -



-_-_MW W a-M --a- R_- 0-- _10 ____ R _' __ _

0-
Bcncaqfl7K3


~4W64


Qucmt SxTm sEP7h~ aocn


FHe. 5.-Average yields of okra generations, the number of pods per plant (cut when in marketable can-
dition) being indicated by heavy lines and the lineal generations connected by dotted lines. The dates
are those of planting.

"counted. Table III shows the results of the plantings of this variety
of tomatoes.
Table III.-Tomato Royal Red generations.


Date of planting.


Mar. 12,1910........
Sept. 17,1910.........
. Mar. 11 1911-.........
Oct. 16 1911 ........
Mar. 12, 1912.........
Do--, 91--: ----------
Do.............
Sept. 14, 1912........

Do,.........
Do ...........
Do..............
Do-..............
Feb. 24,1913....-....
Do.....-...
Do.................
Do.........
Do...............
Oct. 27,1913.......
Do...............
Do...............
Do...............
Do..............


Name.


Primeral st.......
Primera 2d........
Primers 3d........
Primers 4th .......
Primers 5th A....
Segunda Ist.......
Teroera Ist........
Segunda 2d..-....
Primera 5th B -..
Primers 6th A. ...
Cuarta st-......--
Tercera 2d........
Segunda 3d........
Primera 6th B -...
Primera 7th A ....
Quinta 1st.......
Cuarta2d-........
Tercera 3d........
Segunda 4th ......
Primers 6th C.....
Primera 7th B....


Number
of days
from
planting
to blos-
soming.


55
65
62
63
60
60
72
78
64
69
68
66
66
64
68
57
63
61
62
681
62


Number
of days
from
blossom-
ing to
fruit
picking.

39
57
39
49
45
52
50
44
54
41
44
36
35
41
33
48
42
44
43
45
46


Number
of days
covered.



196
(1)
206
220
161
161
191
191
191
191
136
136
136
136
136
180
180
180
180
180
180


Number
of plants.


11
12
11
6
6
4
5
4
5
13
13
13
13
13
12
13
13
12
13
13


Average
number
of fruits
per plant.i
I


A average
weight of
1 fruit.


Grams.
13.6 112.5
8.6 94.5
19.3 86.5
8.0 86.1
5.0 88.3
21.8 85.3
23.8 68.8
23.5 80.8
24.8 73.2
2.2 68.7
3.8 71.3
2.3 67.5
4.7 81.6
3.5 61.7
29.2 93.8
32.1 102.0
30.2 94.8
32.3 88.2
17.6 100.6
27.0 95.6


I Vines thrown down by rainstorm when crop was only partially collected.


P







noTh first planting was, nu6&e Varh i12 #91
tions: were favorable'for a rn rwho ie
frulitingr. Toward the end of Juna, as #Iwost wobiee -
ting fruit and as the plants h9A developed Linto a gret maws
and branches, about a third of the growth was prnmeda
average yield of tomatoes per vine, was not hgbut h
were lafrer -in size than those from any other planting, eveft
four other plantings were made from the same lot of seed.
this age.
Primera. 2d generation was planted September -17, 1910i--
this crop was only partially collected a heavy rainstorm tinue,
the plants, b readingg them badly and knocking off so many rg
fruits that any record of yield was made valueless.' In qu4ll
generation was fax ahead of the Ist generation,, the fruits b6)g g
smoother and firmer with a smaller permenage,:show'ngbroeg
or creases at the stem end, This -difference in. quality was ei
a seasonal effect.
Primera 3d generation was planted March 1:1, 1.911, A yea:
than the first planting. Not only wei-eth fruis con~siderablW
than those of the first -generation, u h averg yedpe
was less than two-thirds th at of the first: planting. Here again,-,
broken skin at the deeply creased stem ends was very noti
many fruits spoiling soon after they were sufficiently ripe for ai
Primera, 4th generation was planted October 16,. 1911. Both
total weight and number of fruits per plant this. exceeded the l]A
,3d generations, but the average fruit was smaller than that of
.3d generation, which, in turn, was smaller than that of the 1st, t
presenting a steady'decline in size. Since the locally grovm ton
is quite small, this would suggest that local conditions perhaps fa
the production of tomatoes yielding small fruits.
This theory, however, was not borne out by the next plnia
which were made March 12, 1912. T~he difference *in swiz bew
Primera 5th A and Segutnda, 1st-generation was so small as to b
ligible The average fruit of Primera 5th generation A mau
2.24 inches by 2.07 inches in horizontal diameters, -and 1.66-inhebw
vertical diameter, while the average fruit of Segunda 1stgerd
measured 2.31 inches by 2.08 inches in horizontal diameotes anud I
inches in vertical diameter. Ile difference in number of se
also wall within the allowance for experimental error, the n
averaging in the former case 106.2 seeds, and in the latter 116.8 e
per f ruit. The advanced generation here produced a greater nn
of fruits than the 1st generation.
Four generations were planted Senptenber 14, 1912) n:1t, a 2
5tiada6h wn ovr e ete n oml






S21

the number of plants was reduced considerably more than was desir-
able for the tests. The production of fruits was very uniform, aver-
Saging from 21.8 to 24.8 fruits per plant. The total yield per plant
Sfor the 1st generation weighed a little less than that of the 5th gener-
Sation and a little more than that of the 6th.
Five generations were planted February 24, 1913. The best plant-
ing made on this date produced fewer fruits than the poorest made at
any other time. The average number of fruits produced ranged
from 2.2 to 4.7 per plant. Beginning with the one giving the largest
-. yield, the generations were in descending order 6th, 2d, 7th, 3d, and
1st.
The last planting was made October 27, 1913. With the exception
of a 5th generation, all generations from 1st to 7th were represented.
SFrom some evidently very local but unknown cause the plants in one
Send of the row of Primera 6th C were dwarfed and greatly retarded in


*hi deveomn m-ate-------orilys- decreasin the-- yiel o-ti rw h
V 4 OCn 2 7od .
.v P --OC 73



eh o t ", he 2 gnro er ar
.4 ge in___ I..._e the :.. E p i P






o 0 /M" 6-ny 62- 7 72" /r 2 ?" W 3 42 /17 P! 3pl / nPg /.

FI. 6.-Average yields of Royal Red tomato generations, the number of fruits being indicated by heavy

their development materially decreasing the yield of this row. The
other rows gave an average yield of 27 to 32.3 tomatoes per plant,
the 4th and 2d generations leading in number of fruits produced. In
size, the tomatoes of the 2d generation were the largest and those of
the 4th generation were the smallest. Excepting Primera 6th C, the
yield of the poorest row planted at this date exceeded the best yield
of any other planting.
In figure 6, the number of fruits produced by each planting is dia-
grammatically shown in connection with the number produced by its
lineal forbears and its descendants. The planting dates are appended
in each case. This diagram is so similar in form to that showing the
total yield by weight of fruit produced by the average plant that the
latter diagram is not included.
These diagrams clearly show that there is no uniformity of behavior
where the number of ancestral generations grown in the Tropics is
considered as the main factor. Tlly decreasing the yield of this is particularly noticeable in the
considered as the main factor. This is particularly noticeable in the


ii:
tr







.,



I

V;








..

:EE.::ll.

,.'

; .







Pr~ragroup, of -which mprelsig Se-ae
Teone striking feature is the grouping of tho Ute,
dtson the one hand and the autuum. pl 9-n dat** (ft
soing the -planting, date -to have .been -the real, fsotor ilu P
teyield. In figure 7 this is. clearly demonstrated vhft *-
smade on the same date are connected by lines'. The sa
ofte 6th generation *in the October, 1913, planting, whichiiw
onything to mar the, symmetry of this chart, has alredy,
exlinedi.
The tomatoes planted in the fall on the whole had it slightly
aeage size than those planted in the late winter and spring
-hswas not uniformly the case. However, the main fcor









2Ae8eyed fRylRdtmt eeaios h ubro risbigidctdb
line an siultneou plntigs onnctedby ottd lneZ
re the time of p~~~~~~~laie'.Tenme facsrlgnrt
22hdbe rw nth rpc aldt so n feto i
nO anlsso h hlesbetsosta, huhtmte
Nhr edwr rw o ee gnrtosi h rpci
/g0 fhbttapretyhdn fet nete ieo





MG.ow. Thrae yieldnoeRoal Rdtomatomenertifolnoedw the nmeofmisabe* Ia tha by
Roylines andrimutaneouseptltantig lnesse byanurdlie wsue n'

Ananalyisn of the whole subec rshows o that although toatoesnv





23

TABLE IV.-Tomato Honor Bright generations.

Num-
mber of Ver-
ber of Aver-
days tical
days Num- age Aver- Horizontal am-
from berof Num- num- age diameters eter
Date of planting. Name. plant- som- days ber of ber of weight e
ing to cov- plants. fruits o fruit. aver-
Sfrutblos- ered. per fruit.
frusom- plant, age
lg.o pick- plnt. fruit.
g. ming.

Grams. Inches. Inches.
Dec. 10, 1910........ Primera 1st....... 57 48 208 6 51.2 104.6 2.57 by 2.37 1.77
May 24, 1911........ Primera 2d A.... 82 196 278 8 .3 13.0 ...................
Mar. 12, 1912....... Primera 2d B.... 60 45 161 8 3.1 78.9 2.20 by 2.01 1.53
Dec. 10, 1912........ Primera 3d........ 60 42 210 7 90.7 104.9 2.43 by 2.40 1.80

The first planting was made December 10, 1910. The fruits were
large to medium in size, and the average production per plant was
51.2 fruits.
The first planting of the 2d generation was made May 24, 1911.
By the middle of August the plants began to blossom. In early
October it was noted that blossoms were seen only very rarely and
that these did not set fruit. By this time one plant had died, and
Stwo more were nearly dead. Near the end of February of the follow-
ing year, two tomatoes, one weighing 18 grams and the other 8 grams,
were produced on plants which were then entirely leafless, only one
plant still having green leaves. This demonstrated very forcibly
the uselessness of attempting to produce tomatoes in the season of
heavy rains.
A second planting of the 2d generation was made March 12, 1912.
The fruits produced were small in size and few in number. They,
however, furnished sufficient seed for a planting of the 3d generation.
The 3d generation, which was planted December 10, 1912, far
excelled any other planting. The average size of the tomatoes was
about the same as that of those of the 1st generation, but the number
produced was 90.7 fruits per vine. The total weight of fruit per vine
was about 21 pounds.
The yields showed the seasonal effects in even more pronounced
contrast than did the plantings of Royal Red tomato, though fewer
plantings were made. The data serve to substantiate the conclu-
sions reached in the tests of the other variety.

LETTUCE.
The lettuce plantings were from seed of Prize Head lettuce, grown
in California and received in the Congressional seed distribution of
1909. The young plants were transplanted to individual pots 10 to
13 days after sowing. When sufficiently large, two or three weeks
later, 25 to 30 plants were set in the field, 1 foot apart in the row.







Where- a plant was *injured so 8 asb 0

plan tswr e o ed). and th te e" ont to, O"O t
Igs of J' no plants weft
sednebes er cut at th fis -iation of E los
staring. up. Whr one or seea .red leaves were fouMd
were discarded land the headthen wihed. The rmii
were then counted, including al n-nhor more in, length.
ing the plantings on the last todats measurements were,
the, length and breadthi of th 1 otr leaveston 'Six &vragwV1
of each planting, the length ben measured along the midribd
breadth at the widest portion the laf. The results woe'g
Table V
TABLE.V gml aeram.


Date of planting. Name. h


Grams.Inse
MXp.12, 1910. _--_------- Primeralst .... .....3 169A.2 2 7 6 4
Jan' 2' 1911 _--_-_-----. Primera 3d .. -_---- _- 75 97.0' 195* 5.50:
Jl 6,11.. ..... .... Primera 4th... ------ 76 564.2 18.7 4, 60
DOC 131 oll -------_-- Primera 5thA ....... 72 124.4 27,3 5.94
36r. 12, 1912.. ------_---- Se-gunda Ist --_----- 66 195.0 219.3 6.,04
Primera 5th B........ 66 223.1 30.8 V.I*
Nov. 7, 1912 ...... ....... Tercera 1st... .. ..... 72 6313 18. 0 ... ..
Mar. 27,1913 .._. --------- CuartalIst............. 75 199. 4 28.9 ... .. .
Tercera 2d A ... .... ... 75 '136.1 2A. 6 ..... ...
Jan, 17, 1914.......... ..... Quinta 1st .......... 74 127. 8 25.1 ------
Tercera 2d B .......... 74 '109-.2 2CZ.2

"The first planting, which wsmad Mlarch 12, 1910, gave a so
factory yield.
_.Seed from this generation -weei pated repeatedly, -but sufo
plants for a test were never obained This same condition ofpod
seed with a low percentage of vibilty was found to be, quite cond
where plants blossomed and sed was produced mi rainy wefather,.
Four 2d generation plants were finaly obtaine-d,:but only one p
these lived to blossom. Fro this plnt seed ri-pened. in Decent'
and was used for Primera 3d geeratin-, which was planted Joana
21 1911. Though this generatio wa left -uncut 12 days longer h
the 1 st generation, the plants poduce fewer and smaller leaves a
weighed considerably less. -Rpe sed was collected fromth
plants in May and June.
Primer'a 4th generation wa plante July 6, 1911. I ..u
and size of leaves and weight ofhad itfll far below the 3d goner
Primera 5th A, which was plated Dcember 13, P1911, prods
much better -growth than eite of istwo nearest ancestral 0,
-//,bt nwihtiddnteul h eeain






25'

::Two years after the original planting a simultaneous planting was
miade of a 1st generation and a 5th generation. Owing to very wet
weather, very few and poor seed were obtained from the 4th genera-
tion,and the young seedlings from this generation were much slower
:!:in germinating and, as young plants, were vastly inferior in size to
ithe plants of the contemporaneous 1st generation. However, before
maturity the average size of plants of the 5th generation was con-
S siderably larger than that of the 1st generation plants, not only show-
m ing no degeneration, but excelling in size the 1st generation plants,
I even though handicapped by a poor start.
The leaf measurements of these two simultaneous plantings showed
i no change to have taken place in the general shape of the leaves.
SThe 5th generation showed a tendency toward earlier blossoming
than the 1st generation.
On account of rainy weather no seed was obtained from these
Plantings.
S Seed from 5th generation A and seed of the original lot were
sent to Washington and planted at Arlington Experimental Farm
. through the kindness of the horticulturist, D. N. Shoemaker. He
reported in letter of December 31, 1912, as follows:
iii On July 3 it was noted that the 6th generation lettuce in comparison
With the other two was decidedly less frilled and not quite so deep in color. On
July 13 it was noted that the 6th generation showed smoother edges and lighter
: color, but was larger and more vigorous in plant than the 1st generation or the Amer-
; ican seed. On July 30 it was noted again that the lettuce of the 6th generation was
certainly not so deep in color and was less frilled to the edge of the leaf than the 1st
: generation. Also it was quite notable that it was tenderer than either of the other
i numbers planted for comparison.
A, On September 4 we noted on some plants which had been lifted and planted in a
Frame that the plants of the 6th generation grown in Porto Rico were larger and more
vigorous than the others but were rather inferior in varietal character.
SWould say in summing up the observations that the difference between the lettuce
' of the 6th generation and first generation from Porto Rico seems very likely to be
I: that which would result from a selection of the varieties in any region without a strict
: adherence to the varietal type; that is, that the difference observed here would very
l readily occur in the same number of generations on any American farm if the seed-
.bearing plants each year were not strictly compared with an ideal varietal type.
Several other plantings were made in Porto Rico after this date.
.. On November 7, 1912, another planting of 1st generation was
,:made. The heads were next to the smallest of any produced.
aMeasurements of the average length and breadth of the 12 outer
e;|faves on six average heads showed that in the 1st generation the
Fength and breadth of leaf were not in uniform relation, since on three
heads 'the sum of the leaf lengths exceeded the sum of the breadths
Each case, while the reverse was true with the three others. This
k of uniformity was also found in Primera 1st but did not appear
4 Primera 5th B or Segunda 1st. Its appearance in two 1st genera-







tion plantings shwdit to tablo, a fee
.frther leaf meas urits wereot taken. '
Two'mnore planig -of 1s gnration,$ were m-940 A"
with 2d, generation and ech instance the let gnr
the better yield.
In only the earle of thes two: plantings were plants left
In this &instance th 2d genraion showed a: tendency toward'
blossoming than teIst.
In reviewing the varos letce plantings, no, degeneration
by being grown for anmbe of generations in the Tropics 1's"
On the contrary, inication point toward an improvements`
advanced generating
The production o well-fored and viable lettuce seed iu
seasons here is pracically impossible, &nd for this 'reason
usually be found betto imprt seed for thisco. heif
in yield of 1st an 2dgenertions, when. planted simultanoon
may or may not hav been du in part to a difference'in vigor,
by a difference in, ie of seed
As with the ote crops pevioiisly. discussed, the prime
dfluencing producto seemed to be the planting season.

PRESERVING TRY VIABITY OF VEGETABLE SR
The humidity ofte a Port Rico. is very hh and
vegetable seed ,expsd to th open air to,, lose their viability
sooner- than' would the caein a drier atmosphere. The 4
to keep seed in godcondiin is a serious hindrance to v
growing. Wheftth experimnts herein reported were undertal0
the following. -metho for preeving. seed was employed and was
satisf actor~y. Thesed in coton sacks was placed in air-tight
jars in the bottom o which aew ounces.of calcium chilorid had
placed. A small pic of wiescreening separated the seed froain
calcium chlorid belw (Se fg. 8.). This method is simple and
-i~ttle, and is recommended fo general use. While glass jars -w4
used in experiment meta or nonporous earthen vessels will, se
as well if made airtiht. tnust be remembered that thecac
chlorid placed in th ottom of the j ar is used as a drying agent, p-
not as a preservaiv in another sense. Seed such as coffe-e
citrus, which lose thir' -viailty on drying, can not be kept via,
in this way. If see with a early high water content is to 'be sor
it may be necessary to ree the calcium chlorid, since, ne
sufficient quantityo calcium chlorid is used to take up the
water, the seed ma not be ket sufficiently dry. Before the t
chlorid becomes entirly most it should be replaced by a fresh sa
Iri handlnge it, sho hlab exosd as short a. time as possible ton





27

Iti drying power. In removing seed from the container this should
We remembered.
Germination tests were made of seed of a number of different vege-
0Itables, a Geneva seed tester being used. To bring out more clearly
he results of these tests, they have been plotted as curves. The
native tomato seed of which tests are recorded in figure 9 was col-
;lected in the winter of 1910. The other seed was imported, coming
I I


FIG. 8.-Air-tight jar illustrating method of preserving seed over calcium chlorid.
presumably from the 1909 crop. A portion of each was kept in the
dirier and another portion was exposed to the open air.
. In the last germination test of bean seed which had been kept in
Sthe open the seed was put in the tester October 29, 1910, germinating
I:4 per cent. On this date, 100 per cent of the seed kept in the drier
germinated. This seed from the drier still showed a 100 per cent
I germination nearly two years later, August 13, 1912, when the tests
-bad to be discontinued on account of a scarcity of seed.







































so
60




^ 20 ------- --------,--- ----.-- -_ -







40J
20.: .
0 K- -. -. .
/ "" ... ..






























FI*. 9.-Results oI germinatin tests o seed. The unbroken line show. the g ka"titm
8 0 W *...... :

.....60 -..-.--






40---T 7----- --


O --- -11 -1 I ^^-- ---- ---^- --

do .-.- -" _"- -. 1





60- 7 -- -






... ...

FIG. 9.-Results of germination tests of seed. The unbroken line shows the germination of skellel

sme lot kept hn cotton sacks exposed to the air. .'.:;:
/00:E:
.kE : ..:.
..T.. ,.. ; :
... ..".. ....0.': i,. ,;i
..1.:70'."? ".:. :
..2..0.. .'. :" i
7 M P"k."..=
':O... L






29

SBy the end of 1911 all of the imported seed kept in the open air
Shad lost its viability. In 1915, 94 per cent of the radish seed and
84 per cent.of the beet and tomato seed kept in the drier still
Germinated.
Unfortunately, the supply of okra seed in the drier was too small
to allow a long continuance of tests. On November 4, 1911, 100
S per cent of the seed from the drier germinated, while of that in the
S open only 2 per cent germinated. It was found necessary before
planting to file okra seed which had been kept in the drier.
The native tomato seed, after more than five years in the drier,
showed a germination of 93 per cent, whereas seed kept in the open
S. lost all viability in less than half that time.
In figure 10 the loss of viability of imported seed of a number of
different vegetables is graphically shown. The very rapid loss of
/ s9/ /9// /s/2












were from the 1910 crop. The dates of the germination tests are given above. To eliminate as far a;
possible errors of individual tests, the curves were plotted by connecting points midway between the
gemfnation percentages so as to occupy a mean position in respect to them. Tests not made were of
ale Aug. 27, 1910; turnips, Dec. 31, 1910; okra, Sept. 9 and Nov. 4, 1911.
S10.oss of viability of lettucimported vegetable seed keptexposed to the open air stands in marked con-


trast1910, withre of seed presumably olletests of seeding seaof the same lot which had been
kept infrom the 1910 crop. The dates of the germination tests are given above. To eliminate as far cent



in 1915.
In figurble error the loss of individual tests, he urves were plotted by connecting points midway between th

SUMMARY.
That northerentages so as to occupy a mean position in respecttables degenerate quickly when taken to them. Tests not made were of
kaleTropics is a common belief in Porto Rico, resulting from the fact
that seed loses its viability of lettuce seed kept in the open expoair stands in moist air and









trast with the relack of knowledge regarding season effect whihon vegetable
kep t in the drier and which showed a germination of 90 per cent
in 1915.
In figuretain the viability of seedviability of the rops used in the experiments
SUMMARY.

here reported, then vegetables stored in air-tight jars in the botto the
Tropics is a common belief in Porto Rico, resulting from the fact
that seed loses its viability quickly when exposed to moist air and
j| from a lack of knowledge regarding seasonal effect on vegetable
H- production.
(^ To retain the viability of seed of the crops used in the experiments
it: here reported, the seed was stored in air-tight jars in the bottom
of which was placed a small quantity of calcium chlorid. This
Method was so satisfactory that it is recommended for general use.







Pantn a few types of peppers, such'aser'f
Porto IRico, side by side with varieties, imprt n
sowed that the Porto Rican types are much more'po
ter-efore more desirable than imported varieties.,
Forty plantings of .beans were made, include nine gnr
Ofthe.-Porto Rico plantings, those made, in March gaVe latge
ecept one in 1911, which was hindered by an exceptionaldo
while .those made in other months, including 'June, Septlemb
November, December, and January, gave small harvests. No"
nations, that advanced generations were inferior -to earlier ones w
observed.
Records of the five years' work. with okra, during which time
plantings were made, reaching finally the eighth, generation, shr

47 IV zw 1W 40 48_W6 7R 60 6V _196 /OW t
aoo
.4 1 0
Al





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ma*de from the averages of 429 different lots of seed, the tomato carve from 6, the bean curve from 5, apd
the pepper curve from 3. S ince the ripening season in many instances extended over a period of a number
of weeks, the picking date was arbitrarily assumed and the tests were therefore only approximately so
many weeks after picking.
that the growth and production of the advanced generations are not
iferior to those of the earlier ones.
The development of plants of the different generations of *tomatoes,,,,
gown in Porto Rico was very uniform and proves that, except for
ocasional importations, the seed of this vegetable needed in Porto<
Rico can well be grown in the home gardens.
In the work with lettuce no degeneration was noted as a result of
growing an imported variety for suessive, generations 'm Porto
Rico. Owing to the difficulty of producing seed during seasons of
havy rain, the experiments with this crop were hindered consider-
aby. As seed production is difficult and loss of viability rapid, it
will probably be necessary to import the seed of this crop.
In all vegetable plantings the season at which the planting was
made had a very pronounced effect on the vield. being the predomi,
natfco nlecn rdcin















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