COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS
STATE OF FLORIDA
COLLEGE Of AGRICULTURE, AGRICULTURAL EXTENsrON SERVICE
UJrIVER5s Y OF FLORIDA, AND Vegetable Crop Specialists COUNTY AGENI ,AN
UNITED STATES DEPARTMENT OF HOME DEMONSTRATION WORK
AGRICULTURE. COOPERATING E T a I a GA I ESV LLE FLORIDA
November 30, 1964
TO: ALL COUNTY AGENTS, ASSOCIATES AND ASSISTANTS
The Florida State Horticultural Society meeting held on
November 4-6, was one of the best yet. Thirty-two papers
were presented in the Vegetable Section. As many, or -more,
were presented in each of the other four Sections, This annual
meeting should be a must for anyone engaged in any phase of
horticulture. This is especially true for County Agricultural
Agents, who, in many instances, work with all phases of horticulture,
In this issue of the Vegetarian, we have chosen to review some of
the papers presented in the Vegetable Section which we feel may
have practical application to your problems now. All of the
papers, including many excellent reports not reviewed here, will
be published in the Society Proceedings due next spring. Get
a copy for your library.
F. S. mison, Head ames monte o
Vegetable Irops Department Associate Vegetable Crops Specialist
Mason E. Marvel
Assistant Vegetable Crops Specialist
1. Dr. V. L. Guzman of the Everglades Experiment Station presented an excellent
paper on "Soil Temperature and Celery Seed Germination", He found that celery
seed germination was stopped at a temperature of 100.50 F. Even though smne
seed germinated at 950 to 980 F., growth of seedlings was greatly reduced.
He concluded from this work that soil temperatures should be prevented from
rising above 900 F. in celery seedbeds. Common practice is to shade celery
seedbeds with cheesecloth during the hot months of the year. These same
principles apply to many other vegetable crops started in hot weather in
2. Dr. Guzman also reported on a study in which he compared a so-called "precision
planter" versus a conventional planter now coanonly in use. In general, he
concluded that the conventional planter was as good or better than the pre-
cision type planter tested for two seasons.
The results of the second test were more nearly equal in yield and quality,
indicating that refinements made in use of the precision planter are promising.
Labor shortage may, in the near future, force growers to use precision planters
to a greater extent. There is every reason to believe that this type of
planter can be improved considerably and should be in general use within the
next few years.
3. Dr. Phil Minges, Cornell University, in a report on "blotchy ripening" of
tomatoes proposed that this disorder encompasses several abnormal conditions
previously thought to be unrelated. He stated "that two internal expressions,
namely abnormal "white tissue" and dead "brown tissue" are the basic symptoms
and lead to a range of external expressions depending on the location of the
white tissue in the pericarp wall". Graywall, according to his theory, is
an expression of the same underlying factors causing surface blotchy ripening
or internal white tissue.
He has been able to virtually eliminate the disorder in greenhouse nutritional
studies. His work sheds considerable light on a baffling problem. It is an
excellent start that may eventually lead to practical control.
4. Dr. Paul Sutton, Strawberry Investigations Lab., reported on NPK fertilization
of collards. He found that nitrogen levels had the most significant effect
on increasing yields. Nitrogen intensified the green color of the leaves as
well as improving quality in general. The responses to P and K were generally
5. Doctors S. J. Locascio, P. H. Everett and J. G. A. Fiskell, working jointly
in Gainesville and Immokalee, described copper deficiency in watermelon found
on Leon fine sand at Gainesville. Copper deficiency caused a severe stunting
and poor or no fruit set.
Addition of 3 pounds of CuEDTA (a chelated copper), 10 pounds Frit 503, or
one-fourth of the nitrogen from Chicago Sludge controlled the problem.
Chicago Sludge was found to contain significant amounts of copper,
6. Fertiliser placement, use of organic nitrogen and time of applying plastic
mulch was the subject of another paper presented by Dr. Locascio. In this
study, he found no significant effect from organic over inorganic nitrogen.
When fertilizer was applied broadcast, highest yields were obtained by
applying plastic mulch at planting. Banded fertilizer produced the highest
yield when the fertilizer application was split and the mulch was applied
one month after planting. Yields were not affected by time of fertilizer
and mulch application when one-half of the fertilizer was broadcast and
one-half was banded.
7. Dr. R. B. Workman, Potato Investigations Lab., discussed research on the
control of the southern potato wireworm. This soil insect has developed
resistance to some of the insecticides used in the past.
In field tests conducted for several years, he found that Diazinon, Di-Syston,
Parathion and Thimet gave excellent control of the southern potato wireworm
at Hastings when properly applied.
8. The results of a very detailed study on compatibility of insecticides and
fungicides on pepper were reported on by Dr. J. P. Jones and Dr. Eugene
Kelsheimer of the Gulf Coast Station.
In general, captain increased and DDT decreased yields. Insecticides increased
yields during the spring but did not influence yields during the fall.
Excellent aphid control was obtained with dimethoate, adequate control with
diazinon and poor to no control with parathion or guthion.
DDT, in general, reduced foliage damage caused by lepidopterous larvae but
certain combinations of DDT did not.
No foliage injury developed during either season. Certain combinations of
tri-basic copper sulfate, parathion, diazinon and DDT caused some fruit in-
9. Dr. R. E. Stall presented two papers on work done at Fort Pierce on botrytis
control in tomatoes. The first dealt with chemical control. He reported
that dyrene and thiram were about equal in preventing gray mold of tomato
caused by Botrytis. These two fungicides were effective against foliage,
fruit rot and ghost spot phases of the disease. Ferbam was less effective
in controlling these phases. Captan effectively prevented the ghost spot
phase, but not foliage lesions or fruit rot. Dichlone was most effective
against fruit rot,
10. In a second paper, Dr. Stall and associates described the effect of calcium
and phosphorus on the incidence of botrytis in tomatoes. He reported that
liming acid sandy soils with dolomite or hydrated lime reduced the incidence
of gray mold, caused by Botrtis, on tomato. The amount of disease decreased
as tomato leaf calcium content increased and leaf phosphorus content decreased.
The least disease incidence was on plants with high calcium and low phosphorus
contents and the most disease was on plants with low calcium and high
The balance between calcium and phosphorus was found to be important, since
plants with higher levels of both calcium and phosphorus had similar disease
incidence as plants with lower levels of both calcium and phosphorus. Soil
pH and vine vigor were found to not be primary factors in disease development.
11. Dr. R. S. Cox, Crop Production Consultant, Lake Worth, Florida, presented a
paper entitled, "Shoulder Pox, A New Disease on Tomato Fruit". The disease,
according to his report, caused a multi-million dollar loss to the vine-ripe
tomato industry during the 1963-64 season. Symptoms initiate on shoulders
of fruit as a superficial russet that may, through tissue collapse, develop
into a definite sunken lesion. The disease predominates on mature, exposed
fruit that has been subjected to extended periods of low temperature and free
moisture. The disease did not develop in observed fields where oil-emulsion
insecticides and maneb-copper combination sprays were discontinued during the
described weather conditions,