• TABLE OF CONTENTS
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 Copyright
 Table of Contents
 Introduction
 The gladiolus breeding program
 Influence of conditioning treatments...
 Influence of ethylene and preservatives...
 The influence of insecticides applied...
 Gladiolus disease response to prestorage...
 Gladiolus fusarium disease reduction...
 Evaluation of dowicide "2" as a...






Group Title: Research report - Bradenton Agricultural Research & Education Center - GC1979-5
Title: Summary of gladiolus research studies at the Agricultural Research and Education Center, IFAS, University of Florida, Bradenton, FL for 1978
CITATION PAGE IMAGE ZOOMABLE PAGE TEXT
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Permanent Link: http://ufdc.ufl.edu/UF00067758/00001
 Material Information
Title: Summary of gladiolus research studies at the Agricultural Research and Education Center, IFAS, University of Florida, Bradenton, FL for 1978
Series Title: Bradenton AREC research report
Physical Description: 6 leaves : ; 28 cm.
Language: English
Creator: Waters, W. E ( Will E )
Agricultural Research & Education Center (Bradenton, Fla.)
Publisher: Agricultural Research & Education Center, IFAS, University of Florida
Place of Publication: Bradenton FL
Publication Date: 1979
 Subjects
Subject: Gladiolus -- Research -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: W.E. Waters, editor.
General Note: Caption title.
General Note: "April 1979."
Funding: Florida Historical Agriculture and Rural Life
 Record Information
Bibliographic ID: UF00067758
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 - 73265072

Table of Contents
    Copyright
        Copyright
    Table of Contents
        Page 1
    Introduction
        Page 2
    The gladiolus breeding program
        Page 2
    Influence of conditioning treatments on floret opening of cut gladiolus spikes
        Page 2
    Influence of ethylene and preservatives on floret opening of cut gladiolus spikes
        Page 3
    The influence of insecticides applied to glaiolus on insect control and crop tolerance
        Page 3
    Gladiolus disease response to prestorage corm inoculation with fusarium species
        Page 4
    Gladiolus fusarium disease reduction by soil fertility adjustments
        Page 4
    Evaluation of dowicide "2" as a substitute for dowicide "B" in controlling Gladiolus corm rot
        Page 5
        Page 6
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







AGRICULTURAL RESEARCH & EDUCATION CENTER
IFAS, University of Florida
Bradenton, Florida

Bradenton AREC Research Report GC1979-5


April 1979


SUMMARY OF GLADIOLUS RESEARCH STUDIES AT TIE AGRICULTURAL RESEARCH AND EDUCATION
CENTER, IFAS, UNIVERSITY OF FLORIDA, BRADENTON, FL FOR 1978
W. E. Waters, Editor

CONTENTS
PAGE

Introduction ...................................... ...... ............. ... 2

The Gladiolus Breeding Program ................................................ 2

Influence of Conditioning Treatments on Floret Opening
of Cut Gladiolus Spikes ................... ............................. 2

Influence of Ethylene and Preservatives on Floret Opening
of Cut Gladiolus Spikes ......................................... ......... 3

The Influence of Insecticides Applied to Gladiolus on
Insect Control and Crop Tolerance ................................... 3

Gladiolus Disease Response to Prestorage Corm Inoculation
with Fusarium Species ......... ............................ .. ....... 4

Gladiolus Fusarium Disease Reduction by Soil Fertility Adjustments ........... 4

Evaluation of Dowicide "2" as a Substitute for Dowicide "B" in,
Controlling Gladiolus Corm Rot ........................... ............. 5


Information in this publication is a presentation of research results and does
not constitute recommendations or endorsements of chemicals or practices tested.




-2-


Summary of Gladiolus Re$earCh Stddies at the
Agricultural Reseatth and EdUcatiod Cehtet, IFAS, University of Florida
BradentoH, Miod'da ddHing 1978

IfinRbDCTIon
Research on breedihgi production, and post-harvest handling of gladiolus was
continued under several projects at the Agricultural Research and Education Center,
Bradenton, Florida during the past year. Significant advances were made in (1) the
breeding program, (2) understanding the relationships of Fusarium' iTsease and soil
fertility,,(3) clarification of the effects of different Fusarium species on corn
rot, (4) the evaluation of Dowicide 2 as a potential bulb dip, (5) insecticide
studies, and (6) influence of conditioning ethylene and preservatives on floret
opening. Other activities included growing the All America Gladiolus Trial Gardens
and quarterly publication of the GladioGrams Newsletter.




THE GLADIOLUS BREEDING PROGRAHI

Gary J. Uilfret, Associate Geneticist
AREC-Bradenton

The gladiolus breeding program has made progress in developing cultivars which
are not only beautiful but healthy. Over 800,000 seeds have been planted during
the past 7 years and the plants were grown to maturity and evaluated for use as:
cut flowers for the Florida industry, cut flowers for roadside and local sales,
landscape flowers, and breeding lines for future hybrids. During the second grow-
ing season the corms were inoculated with a Fusarium complex and planted thereafter
on Fusarium infested soil. Between seasons the corms were held in cold storage
(400F) and received no fungicide dip treatments. Disease eliminated the majority
of the seedlings and only 600+ are being further evaluated for possible release to
the industry and consumers. One seedling, 'Jessie ii. Conner,' will be released
this year as a yellow-flowered landscape plant. The program was expanded in 1975
to include the hybridization of pixiola types, with emphasis on vigor, health, and
beauty.


INFLUENCE OF CONDITIONING 'TREATMENTS ON FLORET OPENING
OF CUT GLADIOLUS SPIKES

F. J. Marousky, USDA Research Horticulturist
AREC-Bradenton
Gladiolus spikes were conditioned by holding cut ends dry, in water, or in 4, 8,
or 16% sucrose solutions for 24 hours at an ambient air temperature of 550F. After
conditioning, spikes were subjected to simulated shipping conditions by holding them
in commercial cardboard shipping containers for 2 days at 500F. Spikes were subse-
quently held at room temperature in water or a floral preservative and the number
of florets opened per spike was recorded.




-2-


Summary of Gladiolus Re$earCh Stddies at the
Agricultural Reseatth and EdUcatiod Cehtet, IFAS, University of Florida
BradentoH, Miod'da ddHing 1978

IfinRbDCTIon
Research on breedihgi production, and post-harvest handling of gladiolus was
continued under several projects at the Agricultural Research and Education Center,
Bradenton, Florida during the past year. Significant advances were made in (1) the
breeding program, (2) understanding the relationships of Fusarium' iTsease and soil
fertility,,(3) clarification of the effects of different Fusarium species on corn
rot, (4) the evaluation of Dowicide 2 as a potential bulb dip, (5) insecticide
studies, and (6) influence of conditioning ethylene and preservatives on floret
opening. Other activities included growing the All America Gladiolus Trial Gardens
and quarterly publication of the GladioGrams Newsletter.




THE GLADIOLUS BREEDING PROGRAHI

Gary J. Uilfret, Associate Geneticist
AREC-Bradenton

The gladiolus breeding program has made progress in developing cultivars which
are not only beautiful but healthy. Over 800,000 seeds have been planted during
the past 7 years and the plants were grown to maturity and evaluated for use as:
cut flowers for the Florida industry, cut flowers for roadside and local sales,
landscape flowers, and breeding lines for future hybrids. During the second grow-
ing season the corms were inoculated with a Fusarium complex and planted thereafter
on Fusarium infested soil. Between seasons the corms were held in cold storage
(400F) and received no fungicide dip treatments. Disease eliminated the majority
of the seedlings and only 600+ are being further evaluated for possible release to
the industry and consumers. One seedling, 'Jessie ii. Conner,' will be released
this year as a yellow-flowered landscape plant. The program was expanded in 1975
to include the hybridization of pixiola types, with emphasis on vigor, health, and
beauty.


INFLUENCE OF CONDITIONING 'TREATMENTS ON FLORET OPENING
OF CUT GLADIOLUS SPIKES

F. J. Marousky, USDA Research Horticulturist
AREC-Bradenton
Gladiolus spikes were conditioned by holding cut ends dry, in water, or in 4, 8,
or 16% sucrose solutions for 24 hours at an ambient air temperature of 550F. After
conditioning, spikes were subjected to simulated shipping conditions by holding them
in commercial cardboard shipping containers for 2 days at 500F. Spikes were subse-
quently held at room temperature in water or a floral preservative and the number
of florets opened per spike was recorded.




-2-


Summary of Gladiolus Re$earCh Stddies at the
Agricultural Reseatth and EdUcatiod Cehtet, IFAS, University of Florida
BradentoH, Miod'da ddHing 1978

IfinRbDCTIon
Research on breedihgi production, and post-harvest handling of gladiolus was
continued under several projects at the Agricultural Research and Education Center,
Bradenton, Florida during the past year. Significant advances were made in (1) the
breeding program, (2) understanding the relationships of Fusarium' iTsease and soil
fertility,,(3) clarification of the effects of different Fusarium species on corn
rot, (4) the evaluation of Dowicide 2 as a potential bulb dip, (5) insecticide
studies, and (6) influence of conditioning ethylene and preservatives on floret
opening. Other activities included growing the All America Gladiolus Trial Gardens
and quarterly publication of the GladioGrams Newsletter.




THE GLADIOLUS BREEDING PROGRAHI

Gary J. Uilfret, Associate Geneticist
AREC-Bradenton

The gladiolus breeding program has made progress in developing cultivars which
are not only beautiful but healthy. Over 800,000 seeds have been planted during
the past 7 years and the plants were grown to maturity and evaluated for use as:
cut flowers for the Florida industry, cut flowers for roadside and local sales,
landscape flowers, and breeding lines for future hybrids. During the second grow-
ing season the corms were inoculated with a Fusarium complex and planted thereafter
on Fusarium infested soil. Between seasons the corms were held in cold storage
(400F) and received no fungicide dip treatments. Disease eliminated the majority
of the seedlings and only 600+ are being further evaluated for possible release to
the industry and consumers. One seedling, 'Jessie ii. Conner,' will be released
this year as a yellow-flowered landscape plant. The program was expanded in 1975
to include the hybridization of pixiola types, with emphasis on vigor, health, and
beauty.


INFLUENCE OF CONDITIONING 'TREATMENTS ON FLORET OPENING
OF CUT GLADIOLUS SPIKES

F. J. Marousky, USDA Research Horticulturist
AREC-Bradenton
Gladiolus spikes were conditioned by holding cut ends dry, in water, or in 4, 8,
or 16% sucrose solutions for 24 hours at an ambient air temperature of 550F. After
conditioning, spikes were subjected to simulated shipping conditions by holding them
in commercial cardboard shipping containers for 2 days at 500F. Spikes were subse-
quently held at room temperature in water or a floral preservative and the number
of florets opened per spike was recorded.








Spikes conditioned in either 8 or 16% sucrose and held in water after simulated
shipping had more open florets than spikes held dry or conditioned with water or 4%
sucrose and held in water after simulated shipping. The use of floral preservatives
after the shipping period aided in floret opening. Spikes held dry and subsequently
placed in floral preservative had more open florets than spikes conditioned in 16%
sucrose and subsequently held in water. Spikes held dry for 24 hours and then
placed in water had fewer open florets than spikes receiving any other conditioning-
holding treatment.


INFLUENCE OF ETHYLENE AND PRESERVATIVES ON FLORET OPENING
OF CUT GLADIOLUS SPIKES

F. J. Marousky, USDA Research Horticulturist
AREC-Bradenton
Gladiolus spikes were harvested at the commercial bud stage (basal florets with
visible petal color). Spikes were placed in water or a sucrose-based floral pre-
servative in flowing;air (ethylene-free) or air containing ethylene (1 or 5 ppm).
Spikes held in preservative in air had more open florets than those in water.
Spikes held in water or preservative in ethylene opened poorly. Spikes held in
preservative in ethylene did not open or have equivalent quality as spikes opened
in water in ethylene-free air.


THE INFLUENCE OF INSECTICIDES APPLIED TO GLADIOLUS
ON INSECT CONTROL AND CROP TOLERANCE

James F. Price, Assistant Entomologist
AREC-Bradenton
Experiment I
Guthion 50% HP (1 lb/100 gal) and Dipel (1 lb/100 gal), Metasystox-R (1i pt/100
gal) and Thiodan (2/3 qt/100 gal) were applied weekly to 14 commercial gladiolus
cultivars grown in Florida. No phytotoxicity developed on foliage or flowers to
which the chemicals were applied before the flowers showed color.

Experiment II
An experimental permethrin formulation (Penick Corp. SBP 1513 1 TEC) was applied
to 'Manatee Rose' gladiolus at the proposed label rate (1 pt/100 gal) and up to 4
times that rate. No phytotoxicity occurred on foliage or flowers frotrl applications
before flowers showed color. 1hen this compound was applied to open gladiolus flowers,
some flowers developed faded spots.
Experiment III
Orthene 75 SP was applied weekly (2/3 lb/100 gal) to 'T-590' gladiolus for
control of an infestation of early instar beet armyworms. This compound provided
excellent control of the larval infestation. Orthene applied weekly at up to 4
times the above rate did not damage foliage or flowers to which the compound was
applied before the flowers showed color.








Spikes conditioned in either 8 or 16% sucrose and held in water after simulated
shipping had more open florets than spikes held dry or conditioned with water or 4%
sucrose and held in water after simulated shipping. The use of floral preservatives
after the shipping period aided in floret opening. Spikes held dry and subsequently
placed in floral preservative had more open florets than spikes conditioned in 16%
sucrose and subsequently held in water. Spikes held dry for 24 hours and then
placed in water had fewer open florets than spikes receiving any other conditioning-
holding treatment.


INFLUENCE OF ETHYLENE AND PRESERVATIVES ON FLORET OPENING
OF CUT GLADIOLUS SPIKES

F. J. Marousky, USDA Research Horticulturist
AREC-Bradenton
Gladiolus spikes were harvested at the commercial bud stage (basal florets with
visible petal color). Spikes were placed in water or a sucrose-based floral pre-
servative in flowing;air (ethylene-free) or air containing ethylene (1 or 5 ppm).
Spikes held in preservative in air had more open florets than those in water.
Spikes held in water or preservative in ethylene opened poorly. Spikes held in
preservative in ethylene did not open or have equivalent quality as spikes opened
in water in ethylene-free air.


THE INFLUENCE OF INSECTICIDES APPLIED TO GLADIOLUS
ON INSECT CONTROL AND CROP TOLERANCE

James F. Price, Assistant Entomologist
AREC-Bradenton
Experiment I
Guthion 50% HP (1 lb/100 gal) and Dipel (1 lb/100 gal), Metasystox-R (1i pt/100
gal) and Thiodan (2/3 qt/100 gal) were applied weekly to 14 commercial gladiolus
cultivars grown in Florida. No phytotoxicity developed on foliage or flowers to
which the chemicals were applied before the flowers showed color.

Experiment II
An experimental permethrin formulation (Penick Corp. SBP 1513 1 TEC) was applied
to 'Manatee Rose' gladiolus at the proposed label rate (1 pt/100 gal) and up to 4
times that rate. No phytotoxicity occurred on foliage or flowers frotrl applications
before flowers showed color. 1hen this compound was applied to open gladiolus flowers,
some flowers developed faded spots.
Experiment III
Orthene 75 SP was applied weekly (2/3 lb/100 gal) to 'T-590' gladiolus for
control of an infestation of early instar beet armyworms. This compound provided
excellent control of the larval infestation. Orthene applied weekly at up to 4
times the above rate did not damage foliage or flowers to which the compound was
applied before the flowers showed color.







Experiment IV
An infestation of gladiolus thrips was controlled by weekly applications of
Vydate L (2 qt/100 gal) applied to 'Intrepid' gladiolus. No phytotoxicity developed
on foliage or on flowers from the Vydate applied before the flowers showed color.


GLADIOLUS DISEASE RESPONSE TO PRESTORAGE CORM INOCULATION
IITH FUSARIUM SPECIES

S. S. 1oltz, Plant Physiologist, and R. 0. Niagie, Plant Pathologist Emeritus
AREC-Bradenton

Constance Switkin, Res. Asst., P. E. Welson, Professor, & T. A. Toussoun, Professor
Fusarium Research Center
Department of Plant Pathology
Pennsylvania State University
University Park, Pennsylvania

'Friendship' gladiolus corms were inoculated with 12 isolates of several Fusarium
species before being placed in cold storage. The various lots of corms had no evi-
dence of corm rot upon removal from storage; after planting, however, crop failures
due to little or no plant emergence were found to be associated with six of the iso-
lates. These included F. moniliforme 'Subglutinans,' F. oxysporum (four isolates),
and F. roseum 'Sambucinum.' Crop yield (flower and corm production) were reduced
signTficantly by inoculation with F. roseum, F. roseum 'Sambucinum,' and F. solani.
Corm, but not flower, production was increased significantly by inoculations with
an isolate (1-685) of F. moniliforme 'Subglutinans.' Plant growth (foliage) in
plots of gladiolus inoculated with i1-685 appeared healthier than growth in any other
plots, including the non-inoculated controls. Flower and corm production were not
significantly affected by inoculation with one isolate of F. moniliforme and one
isolate of F. oxysporum.


GLADIOLUS FUSARIUM DISEASE REDUCTION BY SOIL FERTILITY ADJUSTMENTS

S. S. Woltz, Plant Physiologist and R. 0. i',agie, Plant Pathologist Emeritus
AREC-Bradenton

Gladiolus cv. 'Van Zanten's Glory' was grown in 9-inch plastic pots in a
3 x 3 x 3 factorial experiment with varied nitrogen level, nitrogen source and
liming procedure and inoculated with 43 x 100 microconidia per pot of Fusarium
oxysporum f. sp. gladioli Snyd. and Hans. Roots were cut and inoculum was poured
into trenches made in the soil. The experiment was conducted from February
through Nay. A moderate amount of Fusarium disease developed but differences
were not significant statistically. Plants were removed from the pots and the
same soil was replanted with small 'Uhite Friendship' corms. Disease reactions
were more distinctive with the second planting, indicating the establishment of
differential inoculum potentials. Ammonium nitrogen resulted in a greater inci-
dence of yellows disease than half ammonium, half nitrate. The high lime rate
was associated with less disease than intermediate or low rates. There was a
significant interaction between nitrogen source and lime rate whereby high lime
resulted in less disease for all nitrogen sources. Corm rot response differed
from yellows; liming to higher pH levels reduced rot and the highest nitrogen
level increased disease over intermediate and low levels. Nitrogen sources
had no overall effects on corm rot.







Experiment IV
An infestation of gladiolus thrips was controlled by weekly applications of
Vydate L (2 qt/100 gal) applied to 'Intrepid' gladiolus. No phytotoxicity developed
on foliage or on flowers from the Vydate applied before the flowers showed color.


GLADIOLUS DISEASE RESPONSE TO PRESTORAGE CORM INOCULATION
IITH FUSARIUM SPECIES

S. S. 1oltz, Plant Physiologist, and R. 0. Niagie, Plant Pathologist Emeritus
AREC-Bradenton

Constance Switkin, Res. Asst., P. E. Welson, Professor, & T. A. Toussoun, Professor
Fusarium Research Center
Department of Plant Pathology
Pennsylvania State University
University Park, Pennsylvania

'Friendship' gladiolus corms were inoculated with 12 isolates of several Fusarium
species before being placed in cold storage. The various lots of corms had no evi-
dence of corm rot upon removal from storage; after planting, however, crop failures
due to little or no plant emergence were found to be associated with six of the iso-
lates. These included F. moniliforme 'Subglutinans,' F. oxysporum (four isolates),
and F. roseum 'Sambucinum.' Crop yield (flower and corm production) were reduced
signTficantly by inoculation with F. roseum, F. roseum 'Sambucinum,' and F. solani.
Corm, but not flower, production was increased significantly by inoculations with
an isolate (1-685) of F. moniliforme 'Subglutinans.' Plant growth (foliage) in
plots of gladiolus inoculated with i1-685 appeared healthier than growth in any other
plots, including the non-inoculated controls. Flower and corm production were not
significantly affected by inoculation with one isolate of F. moniliforme and one
isolate of F. oxysporum.


GLADIOLUS FUSARIUM DISEASE REDUCTION BY SOIL FERTILITY ADJUSTMENTS

S. S. Woltz, Plant Physiologist and R. 0. i',agie, Plant Pathologist Emeritus
AREC-Bradenton

Gladiolus cv. 'Van Zanten's Glory' was grown in 9-inch plastic pots in a
3 x 3 x 3 factorial experiment with varied nitrogen level, nitrogen source and
liming procedure and inoculated with 43 x 100 microconidia per pot of Fusarium
oxysporum f. sp. gladioli Snyd. and Hans. Roots were cut and inoculum was poured
into trenches made in the soil. The experiment was conducted from February
through Nay. A moderate amount of Fusarium disease developed but differences
were not significant statistically. Plants were removed from the pots and the
same soil was replanted with small 'Uhite Friendship' corms. Disease reactions
were more distinctive with the second planting, indicating the establishment of
differential inoculum potentials. Ammonium nitrogen resulted in a greater inci-
dence of yellows disease than half ammonium, half nitrate. The high lime rate
was associated with less disease than intermediate or low rates. There was a
significant interaction between nitrogen source and lime rate whereby high lime
resulted in less disease for all nitrogen sources. Corm rot response differed
from yellows; liming to higher pH levels reduced rot and the highest nitrogen
level increased disease over intermediate and low levels. Nitrogen sources
had no overall effects on corm rot.





-5-

EVALUATIOl OF DOdICIbE "2" AS A SUiSTITUTE 'dR bbwiJctDE "B"
Itl CONGiOLLING GLADIOLUS COFM R1OT

R, 0. Magie, Plant Pathologist Emeritus
AREC-Bradenton

Gladiolus growers in Florida and other states and countries have depended on
Dowicide "B" as a post-harvest corm treatment to control corm diseases. The manu-
facture of Dowicide "B" (sodium 2,4,5-trichlorophenate) was terminated early in
1978. Dowicide "2" (2,4,5-trichlorophenol) was believed to be a possible substitute.
Experiments to evaluate Dowicide "2" were begun in June 1978 with financial support
of a grant from the Florida Flower Association and corms donated by manatee Fruit
Company.

One day after harvest and cleaning of 'White Friendship' and 'Flavia' corms
in June, they were treated for 10 minutes in the following dip preparations at a
water temperature of 80OF (270C): 1) Check, dry; 2) Dowicide "B" at 2.5 lbs/100
gallons (pH 9); 3) Benlate 5011 1.7 lb plus Botran 75W 3 lb/100 gal; 4) Dowicide "2"
at 2 lb plus 0.55 lb lye/l100 gal (pH 11.2); 5) Dowicide "2", about 1.6 lb dissolved
in 100 gal to give a saturated solution in water. One pint of Tween 20 (surfactant
from Atlas Chemical Industries) was added to each 100 gal. preparation. For each
cultivar 200 corms were used in each of 5 treatments.

Corms were held in an open shed for 2 weeks following treatment, and then were
stored at 400F until October 5. Corms were planted without further treatment in
50 corm plots. Plots were randomized in 4 replicated blocks.
A count of plants emerged on October 23 (Table 1) shows that Dowicide "2"
delayed emergence. Dowicide "B" has also delayed emergence in other experiments.
Delay was greatest at the high pH and least when Dowicide "2" was used alone.
As in other tests, Benlate plus Botran did not delay emergence.

Data on flowers harvested in December and January show (Table 2) that
Dowicide "2" was as effective as Benlate/Botran and more effective than Dowicide
"B" on 'White Friendship.' On 'Flavia,' Dowicide "2" dissolved in water with lye
was as effective as Dowicide "B", but Dowicide "2" at a lower dosage in plain
water was not as effective as Dowicide "B".
Data on corms harvested in March 1979 (Table 2) show that Dowicide "2" with
or without lye was as good or better than Dowicide "B" and as good as Benlate/
Dotran.
The lower dosage of Dowicide "2" (treatment 5) was not effective enough in
controlling Fusarium rot in 'Flavia' corms. 'Flavia' is more susceptible to the
disease than 'White Friendship.' At a higher water temperature, more Dowicide "2"
would be dissolved, possibly enough to control the disease.
To obtain the fungicidal action of Dowicide "B" at the standard concentration
of 2.5 lb of Dowicide "B" (85% sodium 2,4,5-trichlorophenate), it may be necessary
to dissolve Dowicide "2" with sodium hydroxide (lye) or another alkali. The solu-
tion used in this experiment contained too much lye. The pH should be no higher
than 9 to 9.2. The actual pH of 11.2 caused excessive scarring (burning) or
exposed corm tissue and resulted in some desiccation of corms and retardation of








sprouting and flowering. The higher pH (treatment 4) reduced flowering of 'Flavia'
in relation -to Benlate/Botran treatment but tended to enhance corm production com-
pared to controls, which is related directly to Fusariur control.

These data will be submitted by Florida growers to support their petition
for a 24C State label to use Dowicide "2" on gladiolus corms to control Fusarium
disease.

Until a label is obtained by Florida Flower Association, growers should con-
tinue to treat corms with Benlate plus another fungicide such as thiram, Botran,
Phaltan and captain which are labeled for use on gladiolus. Benlate plus Botran,
etc. have been as effective as Dowicide "B" and less depressant on flowering if
used within 24 hours after corms are dug and cleaned.

Table 1. Emergence counts on October 23, 1978*


10-minute dip treatments, Uhite Friendship Flavia
June 2** (IF) (Flav)

No treatment dry check 187 88
Dowicide "B", 2.5 lb/100 gal (pH 9) 162 58
Benlate plus Botran, 1.7 ib, 3 lb/100 gal 223 129
Dowicide "2", 2 lb plus 0.55 lb lye/100 gal (pH 11.2) 122 20
Dowicide "2" saturated water solution 214 67

*200 corms of each cultivar planted per treatment.

**All dips included 1 pint Tween 20/100 gallons water.

Table 2. Effect of corm treatments on flower and corm production

I[umber marketable spikes [lumber sound corms*
Dip treatment 3F Flay UF Flav

Dry check 198b** 107c 128c 128c
Dowicide B 218b 156b 219b 205b
Benlate/Botran 271a 202a 265ab 243ab
Dowicide 2/lye 263a 155b 284a 265a
Dowicide 2 264a 128c 224b 211b

*Free of visible Fusarium infections

**Values within each column followed by the same letter are not significantly
different at odds of 19:1.




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