Hastings ARC Research Report PR1981-6
CABBAGE INSECT CONTROL IN THE HASTINGS AREA
R. B. Workman, Assoc. Entomologist
FOLLOW ALL DIRECTIONS FOR USE AND SAFETY ON THE PESTICIDE LABEL AT ALL TIMES.
Cabbage Insecticide Amount Cutoff
insects (E-Emulsible) per acre/ (days)
Dibrom 8E 1 qt. 1 One application of a systemic aphicide
Dimethoate 2.67E 1-1 1/2 pts. 3 applied when the leaves begin to cup
Cabbage Meta-Systox-R 2E 1 1/2 pts. 7 usually gives season long control.
aphid Monitor 4E 1 pt. 35 Good coverage is important. Curled
Parathion 8E 1/2 pt. 10 and yellowed heads cannot be cleaned
Phosdrin 2E 1 pt. 1 up. Aphids are not attracted to head-
Systox 2E 1 1/2 pts. 21 ed cabbage--sprays are not needed.
Loopers, EPA emergency exemption expires
Diamond- Pydrin 2.4Eb/ 2.7 ozs. 7 11-1-81. An extension was requested
back moth in August.
Bacillus Cpds: Bactur, Dipel, Thuricide, Etc. Follow label directions.
Other Lannate,Nudrin 90S 1/2-1 lb. 1 Large worms are difficult to control.
cater- Monitor 4E 1 pt. 35 Broccoli-14 days, cauliflower-28 days.
pillars, Dibrom 8E 1 qt. 1 Compounds for loopers control most
Cutworms Parathion 8E 1/2 pt. 10 species. Control cutworms with sprays
Phosdrin 2E 1 qt. 1 or drenches.
M.cricket Diazinon 4E 1 pt. 7 Drench or spray. Do not increase
Cutworm Parathion 8E 1/2 pt. 10 dosage. Burning may result.
(seedbed) Baits Apply during late afternoon.
a/ Adjust dosage for different formulations (2E, 4E, 8E, WP, etc.).
b/ Ambush and Pounce are not available this season because EPA exempts only 1 material
to meet an emergency. Full EPA registration was recently requested for all 3 prod-
ucts from this Center. All have given excellent control of caterpillars during April-
June when populations are highest. This allows for the production of cabbage when
prices, generally, increase. Use of these materials has resulted in reduced spray
application and costs in the area as few insects remain after treatment to develop
further populations and damage. Effectiveness of control appears dependent on expo-
sure of the insects, once poisoned, to sunlight, dry soils, and predators, etc. Under
some conditions of cool-moist situations, recovery has been noted. Thus, sprays in
the late afternoon or night may not be as efficient as others.
Spray nozzles: Arrangements which give good coverage to the undersides of the leaves
are required for the best control because most moths, eggs, and small larvae are found
there. At least 1 nozzle overhead and 2 on drops at the sides of the row and directed
upwards at the head should be used. Recent research with spray booms at this Center
showed that cabbage marketability decreased from 5-66% when drop pipes were reduced to
12" long and 5-76% when drop pipes were not used. Marketability varied between insec-
ticides in relation to length of drop pipe. In general, the less effective insecti-
cides were affected most by change in length of drop pipe. The tests also showed that
insecticide sprayers must be calibrated accurately as to acreage covered. When spray
volume (50 GPA) was decreased 18% by covering more area than the insecticide dosage was
calculated for, cabbage marketability was reduced from 0 to 18% depending on the insec-
ticide used. Losses up to 89% resulted when spray volumes were reduced by 48%. Insect
control also decreased when spray pressure was reduced from 250-150-100 psi.
AGRICULTURAL RESEARCH CENTER, HASTINGS, FLORIDA
Pest management: Cabbage tests for 3 years at 4 Research Centers in FL & GA have
shown that insecticide applications before cupping can be eliminated if caterpillar
numbers are low and webworms are not present. Weekly sprays have given better
marketability than management programs involving the counting of caterpillars or
holes in leaves. Management is not possible unless highly effective insecticides
are used as relatively few caterpillars can cause heavy damage. Sprays can, often,
be eliminated during cold weather in Jan-Feb.
Chop and disc under: Cabbage, and all crucifers in gardens, after harvest to prevent
insect buildup and movement to other fields and crops including potatoes (aphids and
Molecrickets: Drenches are effective as treatments penetrate the soil where mole-
crickets tunnel, insecticide breakdown by exposure to light and air is slowed, and
tunnels about roots are filled in. Treatment about seedbeds is practical as mole-
crickets are good fliers. Treatments for molecrickets will reduce digging by skunks
and armadillos in the rows.
Insecticide Use: Inspect fields weekly for insects. During periods of high insect
activity, regular insecticide application will be better than waiting until damage
occurs. Worm damage reduces yield, quality, and crop return. If insects or numbers
become large, control is difficult, often requiring more pesticide use than if
regular treatments had been made. Use fresh pesticides each season. Opened insecti-
cides may deteriorate rapidly. Do not use ineffective pesticides, skimp on dosage,
or treat during unfavorable weather. Conduct control tests occasionally at your farm
to see how materials perform under your conditions (spray boom, nozzles, psi, tractor
speed, etc.). Keep records of materials used, dates, and results.
Insecticide application: Use proper material and dosage for a particular insect with
thorough coverage. Doubled dosages will not give increased control and may leave high
residues. Use good agitation. Good weed control is necessary for spray penetration.
Do not leave spray mixtures in the tank overnight. Spreader-stickers aid plant pene-
tration and contact of small insects but are not needed for large caterpillars. Most
insecticides contain spreader-stickers as purchased. Too much will cause insecticide
Assessment of Insect Control: Most insecticides remain toxic for several days after
application. Control may be by direct contact of the insect, contact by the insect
walking or crawling over the insecticide deposit, or by ingestion of the pesticide by
feeding on the plant. Cold weather may delay control. Wait several days before
checking insect control. Examine the plants to see how many insects remain and what
kind they are. Check plant damage to see if it is new or old. Old damage has cal-
loused edges. Fresh insect frass indicates insect presence. Old frass indicates
that the insect is dead, pupating, or has moved to another location. Large, mature
insects are most difficult to control but will usually cease feeding and pupate within
a week or so.
Harvest: Fewer wrapper leaves will reduce insecticide residues and insect damage. Do
not treat a field prior to harvest just to clean it up. Inspect first. Treatment may
Pesticide Safety: Follow label precautions. Keep pesticides and containers locked up
when not using or until disposal to prevent accidents or misuse. Do not contaminate
water by spraying, cleaning of equipment, or disposal of wastes. Do not breathe
pesticide fumes or dusts. Do not get pesticides on clothes or person without immedi-
ate removal. Keep records of all pesticide use including kind, amount, method and
date used, etc.