Everglades Station Mimeo Report 62-22 May 1962
ANNUAL VEGETABLE CROPS FIELD DAY
Everglades Experiment Station
Belle Glade, Florida
Thursday, May 10, 1962
RESEARCH STAFF PARTICIPATING
H. W. Burdine, Assistant Soils Chemist
T. W. Casselman, Assistant Agricultural Engineer
W. T. Forsee, Jr., Chemist in Charge
W. G. Genung, Associate Entomologist
V. L. Guzman, Associate Horticulturist
E. D. Harris, Jr., Assistant Entomologist
C. C. Hortenstine, Assistant Soils Chemist
J. R. Orsenigo, Associate Horticulturist
P. L. Thayer, Assistant Plant Pathologist
C. Wehlburg, Assistant Plant Pathologist
E. A. Wolf, Associate Horticulturist
**************** 1 M
Mr. John H. Causey, Palm Beach County
Associate Agricultural Agent, Presiding
9:15 Assembly and Registration
9:30 Welcome and presentation of research reports on subjects including:
1. Vegetable Variety Tests.
2. Spacing with Vegetable Crops.
3. Drilling Celery Seed in the Field and in Seed Beds.
4. Retardation of Deterioration of Some Vegetables After
5. Progress in Development of New Sweet Corn and Celery
6. Soil Testing.
7. Chemical Herbicides for Vegetable Production.
8. Insects of Crucifers and Table Legumes.
9. Control of Corn Insects, Celery Insects and Wireworms.
10. Effect of Soil-Fungicides on Damping-off Fungi.
11. Fungicides for the Control of Celery Diseases.
Tour of experimental and demonstration plots.
C. C. Hortenstine
A factorial experiment involving 2 rates of N (O and 20 pounds), 3 rates
of P (0, 25, and 50 pounds), and 3 rates of K (0, 100,and 200 pounds) was con-
ducted in the fall of 1961 as a basis for soil test recommendations for sweet
peppers. The following table shows yields of peppers and P and K contents of
leaf and soil samples collected when the peppers were about two months old.
Nitrogen had no significant effect and is not, therefore, included in this
* Each entry is an average of 8 plots.
There were highly significant increases
leaf and soil samples due to applied P.
highly significant decreases in leaf and
s in pepper yields and P contents
In Addition, applied P resulted
Applied K had no significant effect on yields, but there was a highly
significant increase in the K content of leaf and soil samples due to applied
There was a significant interaction between applied P and K shown in the
K contents of the pepper leaves and soil.
CONTROL OF SOME NAJOR INSECTS ATTACKING
CRUCIFERS AND TABLE LEGUMES
W. G. Genung
Notes on Control of Some Diseases
W. G. Genung and P. L. Thayer
Major emphasis on insect control relative to crucifers during the past
season has been on cabbage looperl/ and,aphids2, wille on legumes considerable
attention has been given to leafminers_/ stinkbugs/and cowpea curculio2. It
is too early at this writing to report results of current experiments.
In addition to insect control it was observed that some of the insecticides
used on southern peas appeared to strikingly control or suppress certain fungous
diseases. The pathologist confirmed these observations and Dr. Thayer has co-
operated in this experiment, identifying the disease organism and making counts.
The data presented herein is a report of results of research conducted and
not to be construed as control recommendations.
Experiment 1 Nine insecticidal treatments were compared with an untreated
check for control of insects attacking Copenhagen market cabbage in a randomized
complete block experiment. Each treatment was replicated five times. The first
six treatments were applied at weekly intervals with a self-propelled experimental
plot sprayer. Materials were applied at about 100 gallons per acre and 200 psi
with 6502 spraying systems nozzles. A total of 7 applications were made.
The last three treatments were applied but one time when the plants were
quite heavily infested and with about 80% of the plants showing considerable
damage. The insecticides, formulations, amounts active material per acre and
sample size are given in Table 1.
The results of this eperiment are shown in Table 1. They show a high degree
of effectiveness of B. T.- and toxaphene B. T. combination in comparison with
chemicals used alone for cabbage looper, particularly from the standpoint of
damage which was cumulative. This is confirmation of previous season's results.
The data further shows that a native polyhedrosis virus of cabbage looper
is highly effective even when applied as a single application to an established
infestation. The polyhedrosis virus used alone or in combination with B. T.
indicates, from the standpoint of looper reduction, a control equal or superior
to the other treatments on a weekly schedule.
1/ Trichoplusia ni (Hbn), 2/ Myzus persicae (Sulz.), 3/ Liriomyza sp.,
4/ Nezara viridula (Linn.), 5/ Chalcodermus aeneus (Boh.)
6/ B. T. is used in this report for Bacillus thuringiensis Berliner and P.V.
for Polyhedrosos virus.
Experiment 2: This trial was similar in design and methods to experiment
one. Southern peas was used as the test crop. Nine insecticidal materials were
compared with an untreated check for control of the various insects attacking
legumes. The main populations that developed were serpentine leafminers, stink-
bugs and cowpea curculio.
The standard phosphatics were applied twice weekly for leafminer control.
Only two applications of dimethoate were made as it was desirable to see how
long the interval could be extended for leafminer control. The remaining
materials were applied at weekly intervals. All pertinent information re-
garding the treatments is shown in Table 2.
Data taken at the termination of the experiment are presented in Table 2.
Guthion was very effective for leafminers when applied twice per week. Diazinon
and Dibrom also were comparatively effective at this interval for this insect.
Dimethoate was over extended and should have been applied at 10-14 day intervals
for nearly perfect control.
Populations of stinkbugs and cowpea curculio were relatively light. Thiodan,
Dibrom, toxaphene and Guthion appeared most effective against stinkbug. Toxa-
phene and Thiodan gave perfect control of cowpea curculio. Data for stinkbug
and curculio are given in Table 2.
One of the most interesting aspects of the experiment was the observation
that several of the insecticides appeared to give control of certain fungous
diseases. The degree of control was strikingly visible. Counts of incidence
of the diseases were made with Dr. Thayer who found a rustle/ powdery mildew/
and cercosporai/to be present. Several insecticides reduced the incidence of
powdery mildew, however, toxaphene appeared outstanding. Bacillus thuringiensis
Berliner almost completely prevented development of rust while cercospora counts
were much lower in the Trithion plots than in the checks. Correspondence with
representatives of the various companies indicated that only Dibrom, of the
materials used, was known to be slightly fungicidal. The data on disease control
are shown in Table 2.
Experiment 3: This was a randomized complete block experiment with ten
insecticides and three replications. Plots consisted of one row each of cauli-
flower and broccoli. Spray materials were applied as in experiment 1 and 2.
Dusts were applied with a rotary hand duster. The materials used, formulations
and amounts active material per acre are given in Table 3.
At the time aphid control data were taken the green peach aphid was the
only insect species present. The degree of aphid control obtained is shown
in Table 3.
I/ Uromyces phaseoli vignae, 2/ Erysiphe polygon
3/ Cercospora cruenta.
Table 1. Cabbage looper control on cabbage, Fall 1961.
number loopers Average
per six number damaged
Material Formulation Amt./A. head sample heads per plot
Toxaphene + B. T.
+ P. V.
+ P. V.
* 60 cc
5 day count
7 day count
Diseases of Southern Peas, Fall 1961.
per 200 pea
meas Der 200
ave. rating lesions
per six leaf per six
sanile leaf sample
per sq. in.
per six leaf
a applications twice weekly (total 16)
b applications weekly (total-8). -- .
c as needed (total 2, should have been 3)
"""" `~' '~""~"'"
Table 2. Control of Insects and
Table 3. Control Green Peach Aphid in Cauliflower and Broccoli, respectively, winter 1962.
S. D. 3562
Toxaphene A. R.
4 plant sample
sample at thinning
Effect of fungicides on fungus population in the soil
C. Wehlburg and P. L. Thayer
The tests consisted of 8 treatments, including the untreated check, in 4
Soil fungicides Rate per acre
Wylone 300 lbs.
Chloropicrin 70 gals.
PCNB + Captan 75 Ibs. of each
Nia. 5961 80 Ibs. (active)
B 720 75% wettable powder 50 lbs.
DAC 649 120 lbs.
Dexon + 2635 100 lbs.
Each fungicide was dissolved in water and sprinkled on the surface of the
plots after which it was worked in with a rototiller and rolled with a hand
One week after applying the fungicides the plots were planted with 100
spinach seeds, 50 corn seeds and 50 beans.
Soil samples for the laboratory tests were taken one day before planting
and 3 weeks later when the final stand count was made.
Undoubtedly more seedlings would have come up if we would have given them
more time, and some of the seedlings would have died as a result of post-
emergence damping-off if the test had lasted longer. But we had to terminate
it because heavy rains had flooded the field for more than 24 hours and the
seedlings had suffered badly.
Total seedlings per treatment and soil fungi found in the laboratory.
Seedlings per Rhizoctonia Pythium Fusarium
Soil fungicide treatment in o .. %___
Yylone' 35 30 62 65
Chloropicrin 47 37 5 0
PCNB Captan 49 35 82 47
Nia. 5951 53 25 72 72
B 720 47 32 75 60
DAC 649 59 13 5 0
Dexon + 2635 68 0 75 10
Check 38 57 85 90
Although the test had to be discontinued before its time the results show
a correlation between the Rhizoctonia population and the number of seedlings
that developed. The plots treated with yrlone formed an exception. The Pythium
population did not seem to affect the seedling stand. We have not yet tried to
distinguish between pathogenic and saprophytic Pythium species.
The second soil sample taken after the field had dried out somewhat
yielded a completely different fungus population: both Rhizoctonia and Pythium
numbers were reduced considerably in most cases and the Fusarium population had
increased to 100. No attempt has been made to find out how long it will take
for the normal soil fungus populations to build up again.
With tests of this kind we hope to obtain more information about the action
of soil fungicides on the fungus populations and on the crop plants. It may be
possible in the future to check soil samples in the laboratory and from the
results make recommendations for soil treatment with fungicides.
Chemicals suggested for celery disease control in the Everglades
P. L. Thayer
Disease Chemical treatment Comments
Root rots Fumigants Chloropicrin 2 gal.I/ Fumigation preferred
and damping-off Methyl Bromide 24 lb. to drench, especially
Nemex 3 gal. in summer months.
Drench Vapam 3 gal.
Rhizoctonia Tribasic Copper Sulfate (TBCS) 4-100 / Use the same treat-
Stalk Rot Thiram 1-l-100 alone or ments for sedd-bed
1-100 with maneb 1-100 or or field.
Dyrene 1~-100 alone or 1-100 with
Early Blight Dyrene 1g-100 alone or 1-100 with TBCS Tribasic Copper
4-100 or Thiram 1-100 or maneb 1-100 Sulfate (TBCS) can
nabam 2 qt.-100 + ZnSO 3/4-100 be used in the seed-
nabam A40 1-100 + AnSOq 3/4-100 bed until covers are
maneb 1--100 alone or 1-100 with removed. After
thiram 1-100 or Dyrene 1-100 covers are removed
use the same treat-
Bacterial Blight TBCS 4-100 ments for seed-bed
i/ Concentration of preplanting seed-bed treatments given per 1200 sq. ft.
2/ Concentration of spray materials given in lbs./100 gal. of water unless
EES Mimeo 62-22