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 Copyright
 Dormant cormels resist heat
 Hot-water treatment
 Use choice cormels
 Breaking dormaney with Ethylene...
 Equipment for hot water treatm...
 Important points summarized






Group Title: Mimeo report - Gulf Coast Station - 57-4
Title: Hot- water treatment of gladiolus cormels
CITATION PAGE IMAGE ZOOMABLE PAGE TEXT
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00067645/00001
 Material Information
Title: Hot- water treatment of gladiolus cormels
Series Title: Gulf Coast Station mimeo report
Physical Description: 5 leaves : ; 28 cm.
Language: English
Creator: Magie, R. O ( Robert Ogden ), 1906-
Gulf Coast Experiment Station (Bradenton, Fla.)
Publisher: Gulf Coast Station
Place of Publication: Bradenton Fla
Publication Date: 1957
 Subjects
Subject: Gladiolus -- Propagation -- Florida   ( lcsh )
Gladiolus -- Diseases and pests -- Control -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: R.O. Magie.
General Note: Caption title.
General Note: "March 1957"--Leaf 6.
Funding: Florida Historical Agriculture and Rural Life
 Record Information
Bibliographic ID: UF00067645
Volume ID: VID00001
Source Institution: Marston Science Library, George A. Smathers Libraries, University of Florida
Holding Location: Florida Agricultural Experiment Station, Florida Cooperative Extension Service, Florida Department of Agriculture and Consumer Services, and the Engineering and Industrial Experiment Station; Institute for Food and Agricultural Services (IFAS), University of Florida
Rights Management: All rights reserved, Board of Trustees of the University of Florida
Resource Identifier: oclc - 71341463

Table of Contents
    Copyright
        Copyright
    Dormant cormels resist heat
        Page 1
    Hot-water treatment
        Page 2
    Use choice cormels
        Page 3
    Breaking dormaney with Ethylene Chlorohydrin
        Page 3
    Equipment for hot water treatment
        Page 4
        Page 5
    Important points summarized
        Page 4
Full Text





HISTORIC NOTE


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
(EDIS)

site maintained by the Florida
Cooperative Extension Service.






Copyright 2005, Board of Trustees, University
of Florida





pF64I v-'t) Gulf Coast Station Mimeo Report 57-4
4p Bradenton, Florida

HOT-WATER TREATMENT OF GLADIOLUS CORMELS

R. 0. Magie


The need for disease-free gladiolus planting stocks has been evident

for many years. Varieties which had good flower production when first intro-

duced to the trade have become unsatisfactory for commercial use largely bocase

of vascular Fusarium infections. Attempts to develop disease-free gladiolus by

selection and indexing have failed. Investigations by the Department of Plant

Pathology, University of California, Los Angeles, resulted in a hot-water tr.t-

mont for cormels (1951). The hot-water treatment has been tested in Florid

since 13.53, was recommended in 1954, and has been used successfully by a few

growers to produce healthy corm stocks resulting in higher yields of flowers,

corms and cormBls.

The most important diseases controlled by this treatment are Fusari-un,

Stromatinia (Sclerotinia "dry-rot") and Curvularia. Elimination of Fusarium in-

fection was obtained for small cormels but in some tests larger cormels were nct

completely cured of internal infections introduced by hypodermic needle. Internal

infections are found in the "floators", but are probably rare in cormels that

sink in water. Plant growth and flower production from the treated stocks were

greater than from the untreated lots.

To remain disease-free, hot-water treated cormels and planting stocks

grown from them must be grown in new or "clenn" soil. One of the more important

results of the hot-water treatment is a better control of the damping-off and

root-rotting phase of the Curvularia disease. Those infections are not controlled

by the spray materials now used nor by planting in new land because nr2i.' cormels

carry the Curvularia fungus which attacks under the soil, killing th ung plants.


Dormant Cormels Resist Heat

All varieties tested in Florida have tolerated the hot-water treatment

if the cormels were sufficiently dormant. The deep dormancy required is devel-

oped in cormels that are matured in and dug from warm soil and then cured in warm




-2-

air for at least tvo months. Air temperatures above 656 F seem to be suitable

during the growing and curing periods. Cormels grown or cured in cool weather

may not develop the deep dormancy needed to withstand the heat treatment. Also,

cormels are easily killed if treated too soon after digging. Cormels that have

been in cold storage are usually killed by the treatment.

Some growers prefer to hold the cormels that are dug during the late

winter and spring months until August and treat them all in hot water at that

time. They are held in shallow trays under open sheds until treated. One to tw

weeks are needed to thoroughly dry the cormels after the hot-water treatment

before placing them in cold storage. At least four months of cold storage ar-

needed to obtain satisfactory gennination. Longer storage is needed for somn Trn

rieties. Growers prefer to plant in October which is usually too soon to obton.u

good germination. Therefore, it is advisable to hold them in cold storage unt:.l

the following fall or to treat them with ethylene chlorohydrin to break dorn:y

as explained in another part of this report.


Hot-Water Treatment

Place loose cormels in tubs of water to soak for two days. Keep vaes.r-

ties separate and carefully labeled. Skim off and discard all "floaters" becc'uss

they contain air which insulates against the heat, allowing Fusarium mummies to

contaminate the planting. Transfer c3rmels to a wooden frame box or basket cov-

ered with screen wire or hardware cloth and fitted with a door. Submerge in hot

water for 30 minutes, keeping cormels and water stirred to distribute heat uni-

formly. Hold water within one degree of 1356 F. Remove container of cormel- "'yI

immediately plunge into cold running water. Pour cormels into sterilized trays

in thin layers and dry with fans. Avoid stacking trays of one variety over anoth-

er variety to guard against accidentally mixing varieties.

Trays may be sterilized by soaking them four hours in formalin solution

(1/2 gallon to 100 gallons) or one hour in a solution of Dowicide B (6 pounds in

100 gallons). Cormels which are obviously diseased should be soaked for three

hours in the formalin solutiori just before the hot-water treatment.





-3-

Use Choice Cormels

Cormels to be treated with hot water should be taken only from corm

stocks which contain no rogues and which are free of the stunt disease and other

crippling or disfiguring diseases. Healthy, pure mother stocks should be devel-

oped by roguing out diseased, off-color and unproductive plants when in flower.

It is preferable to plant the treated cormels in soil where gladiolus

have never been grown. If disease-infested soil must be used, treat the soil with

methyl bromide, using 2 pounds per 100 square feet on sandy soil and up to 4

pounds per 100 square feet on organic and clay soils. Another method of treating

the soil is to heat it by steam to 1800 F or higher for 30 minutes.


Breaking Dormanoy with Ethylene Chlorohydrin

Growers who wish to treat cormels in July or August and plant in October

should try ethylene chlorohydrin (2-chloroethanol) vapor treatment on a small por-

tion of the cormels. It is not known yet whether ethylene chlorohydrin can be

used on all varieties. Cormels are treated as soon as dried off or they may be

placed in cold storage until a week before planting and then vapor-treated.

Place cormels in a container (55 gal. drum or garbage can) with a cover

fitted with a gasket to make an air-tight fitting. Hold a 3 inch tube of hardware

cloth in center of can while pouring cormels around it. Place enough cheese cloth

or other cloths in top of tube to absorb all of the ethylene chlorohydrin. Pour

the measured amount of liquid on the absorbent material. Seal the lid and hold

four days. Cormels may be planted immediately or held until germination begins.

Caution: Do not breathe vapor of ethylene chlorohydrin.

Use one pint of 40% ethylene chlorohydrin per 100 pounds of cormels or

use 3.5 ounces or 7 tablespoonfuls of 40% ethylene chlorohydrin (commercial) per

cubic foot of air space in container. Anhydrous (100%) ethylene chlorohydrin

must be diluted with water (4 parts of chemical to 7 parts of water by volume)

to obtain approximately 40% solution. A 55-gallon drum has a capacity of approx-

imatoly 7 .ubio feet. The amount of 40% ethylene chlorohydrin needed for a 55-.?s!-

lon drum would be one and one-half pints.





-3-

Use Choice Cormels

Cormels to be treated with hot water should be taken only from corm

stocks which contain no rogues and which are free of the stunt disease and other

crippling or disfiguring diseases. Healthy, pure mother stocks should be devel-

oped by roguing out diseased, off-color and unproductive plants when in flower.

It is preferable to plant the treated cormels in soil where gladiolus

have never been grown. If disease-infested soil must be used, treat the soil with

methyl bromide, using 2 pounds per 100 square feet on sandy soil and up to 4

pounds per 100 square feet on organic and clay soils. Another method of treating

the soil is to heat it by steam to 1800 F or higher for 30 minutes.


Breaking Dormanoy with Ethylene Chlorohydrin

Growers who wish to treat cormels in July or August and plant in October

should try ethylene chlorohydrin (2-chloroethanol) vapor treatment on a small por-

tion of the cormels. It is not known yet whether ethylene chlorohydrin can be

used on all varieties. Cormels are treated as soon as dried off or they may be

placed in cold storage until a week before planting and then vapor-treated.

Place cormels in a container (55 gal. drum or garbage can) with a cover

fitted with a gasket to make an air-tight fitting. Hold a 3 inch tube of hardware

cloth in center of can while pouring cormels around it. Place enough cheese cloth

or other cloths in top of tube to absorb all of the ethylene chlorohydrin. Pour

the measured amount of liquid on the absorbent material. Seal the lid and hold

four days. Cormels may be planted immediately or held until germination begins.

Caution: Do not breathe vapor of ethylene chlorohydrin.

Use one pint of 40% ethylene chlorohydrin per 100 pounds of cormels or

use 3.5 ounces or 7 tablespoonfuls of 40% ethylene chlorohydrin (commercial) per

cubic foot of air space in container. Anhydrous (100%) ethylene chlorohydrin

must be diluted with water (4 parts of chemical to 7 parts of water by volume)

to obtain approximately 40% solution. A 55-gallon drum has a capacity of approx-

imatoly 7 .ubio feet. The amount of 40% ethylene chlorohydrin needed for a 55-.?s!-

lon drum would be one and one-half pints.





-4-

Caution: Ethylene chlorohydrin must be fresh. Obtain a new supply each

season.

Cormels treated with ethylene chlorohydrin may be soaked in water the

usual way before planting. Use clean water and avoid contamination from cormels

not hot-water treated.


Equipment for Hot-Water Treatment

The following equipment designed by a Florida grower can be assembled

on the farm or in any machine shop and can be used to treat up to 20 bushels of

cormels p'r day. Materials include a 6 KW electrical immersion heater with sludge

legs and a thermostat with a range of 500 to 2500 F; two 55-gallon drums, one for

cold water, equipped with a drain and source of fresh water, and the other for hot

water, equipped with a fibre-glass mat wrapped on the outside for insulation; a

hand cart with wood floor under hot-water tank; one or two hardware-cloth baskets

(with door) shaped to fit beside heater in drum; rope and pulley for lifting bas-

ket from the drum and for agitating basket of cormels in hot water. The drums

are placed on the hand cart which is rolled under pulley so that basket can be

transferred from hot to cold water quickly. Electrical connections should be

rnde by an electrician. Dairy thermometers are suitable if checked for accuracy.

For preliminary tests or small lots of cormels, the minimum equipment

needed includes an accurate thermometer, a container for cormels, a method of

heating water in metal tank, extra hot water (boiling) to raise temperature quicl-

ly if necessary, and cold water.

The Department of Agricultural Engineering of the Florida Agricultural

Experiment Stations is preparing instructions for making the cormel-treating equip-

ment in the farm workshop.


Important Points Summarized

1. Hold cormols at least twd months after digging and treat them before cold
weather. Do not treat cormels that are ready to plant ror that have been
held in a cool place.

2. Soak cormels in cool water for two days and discard floaters. Fill wire mesh
basket to two-thirds of capacity with cormels. Submerge and keep agitated for





-5-


30 minutes in water held at 1350 F. Cool immediately in clean, cold water.
Drz and store in partly walled-off section of cold storage where there is
protection from contamination by diseased corms. All possible steps should
be taken to avoid contamination from corms, soil and wind-blown refuse.

3. Hold dry cormels in cold storage for at least four months before planting or
make n trial treatment with ethylene chlorohydrin if planting is to be made
less than four months after hot-water treatment.

4. To promote rapid sprouting cormels mny be soaked for two days or more in cool
water, then held in clean trays and sprinkle daily until the first signs of
sprouting are seen. The larger cormels in the warmer, moist places should be
examined daily in order to keep them from sprouting too much before plantire.
If the treated cormels have been contamicsted by refuse or unsterilized x:0.-
tainers, etc., treat them 15 minutes in N,I.Ceresan solution (1 lb. in 50 grl,
water) and plant in moist soil the some day. Cormels to be treated with i.1I.
Ceresan should not be in a sprouting condition,

5. Plant cormels in "clean" soil. The healthy planting stocks also should be
grown in uncontamti-ated soil. The plantint- stock may be pleated back where
the hot-water treated cormels of that variety wore grown, provided that so.L
insect and nematode posts are controlled.

6. Directions for constructing equipment to treat cormels in hot water may be ob-
tained from the Department of Agricultural Engineering, Agricultural Expcrir ant
Station, Gainesville, Florida


















500 copies
March 1957





-4-

Caution: Ethylene chlorohydrin must be fresh. Obtain a new supply each

season.

Cormels treated with ethylene chlorohydrin may be soaked in water the

usual way before planting. Use clean water and avoid contamination from cormels

not hot-water treated.


Equipment for Hot-Water Treatment

The following equipment designed by a Florida grower can be assembled

on the farm or in any machine shop and can be used to treat up to 20 bushels of

cormels p'r day. Materials include a 6 KW electrical immersion heater with sludge

legs and a thermostat with a range of 500 to 2500 F; two 55-gallon drums, one for

cold water, equipped with a drain and source of fresh water, and the other for hot

water, equipped with a fibre-glass mat wrapped on the outside for insulation; a

hand cart with wood floor under hot-water tank; one or two hardware-cloth baskets

(with door) shaped to fit beside heater in drum; rope and pulley for lifting bas-

ket from the drum and for agitating basket of cormels in hot water. The drums

are placed on the hand cart which is rolled under pulley so that basket can be

transferred from hot to cold water quickly. Electrical connections should be

rnde by an electrician. Dairy thermometers are suitable if checked for accuracy.

For preliminary tests or small lots of cormels, the minimum equipment

needed includes an accurate thermometer, a container for cormels, a method of

heating water in metal tank, extra hot water (boiling) to raise temperature quicl-

ly if necessary, and cold water.

The Department of Agricultural Engineering of the Florida Agricultural

Experiment Stations is preparing instructions for making the cormel-treating equip-

ment in the farm workshop.


Important Points Summarized

1. Hold cormols at least twd months after digging and treat them before cold
weather. Do not treat cormels that are ready to plant ror that have been
held in a cool place.

2. Soak cormels in cool water for two days and discard floaters. Fill wire mesh
basket to two-thirds of capacity with cormels. Submerge and keep agitated for




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