POTATO INVESTIGATIONS LABORATORY
Mimeo Report 61-1* October 1, 1960
CONTROL OF INSECT PESTS OF CRUCIFERS IN THE HASTINGS AREA.
Ralph B. Workman, Assistant Entomologist
For the best results in producing insect-damage free cabbage and other crops
the following should be observed.
1. Application.- Insecticide coverage must be thorough. Most of the
insect infestations on cabbage begin in the curled leaves of the developing
head or on the undersurfaces of the lower leaves.
2. Timing.- Insects are easiest to kill when small. Large mature
loopers ri "aphid heads" cannot be controlled effectively. The time for
control is when the insect, the infestation, and the plant are small.
3. Dosage.- The recommended dosage is adequate if coverage is thorough.
Larger plants require a larger volume of insecticide mixture. Increased
dosages increase costs, safety risks, and residues. If dosages of insecti-
cides are increased, also increase the time limitation before harvest.
4. Equipment.- All above ground parts of the plant must be covered with
insecticide. Drop nozzles are necessary to hit the lower sides of the bottom
leaves. The upper nozzles must be located directly over the cabbage head or
wrapper leaves will deflect the insecticide.
In Table 1 emulsible insecticides only are listed. If other concentrations
or formulations are used, adjust the amount specified accordingly. Dusts
may be substituted at the rate of 20-35 pounds per acre. For sprays use from
50-100 gallons of water or more depending on plant size. Spreader-stickers
have improved aphid control but not worm control in tests at the Potato
Laboratory. Use sparingly. Spray runoff indicates a loss of insecticide on
Endrin has been the best material for control of green peach aphids, cabbage
worms, and loopers in tests at the Potato Lab. Use it twice at about two
week intervals at the start of the season then switch to one of the other
chemicals at weekly intervals or biweekly if you are getting good control.
If control does not appear satisfactory, wait at least three days and check
once more before retreating. To control worms on mature cabbage use
increased gallonages so that the insecticide will run down to the lower part
of the plant. Dusts are effective due to settling.
Observe the safety precautions on the insecticide label at all times.
*Revisib 8f it imeo Report 6015
for Control of Cruciferous Insects in the
Insecticide Amount Minimum
Insect (E = Emulsible) per days before Notes
Cabbage Phosdrin 2E 1 pt. l-cab., broc. Clean up infected pl.ants
aphid 3- c aiflower early in sanson. Check
Systox 2E 11 pts. 221 your tra,7pla~=- _.
Green Endrin 1.6E 1 pt. 3 i Found on under-cides of
peach Parathion 4E b-1 pt. 7 lower leaves. Primary
aphid Phosdrin 2E 1 pt. 1-cab., broc.j source of aphids on
Cabbage Endrin 1.6E 1 pt. 35 1 Some insecticide should
worm, Parathion 4E 9-1 pt. 7 i contact soil on top of
Cabbage Phosdrin 2E 1 pt. 1-cab., broc. rows to kill insects
looper, 3-cauliflower crawling on surface.
Cutworm Toxaphene 8E 1J pts. 7
Leaf- Parathion IE J-l pt. 7
Mole Aldrin 4E 1 qt Apply to soil surface
cricket Chlordane 8E 11 qt. i before planting.