Mimeo Report POL 65
Mimeo Report POL 65-3*
POTATO INVESTIGATIONS LABORATORY
CABBAGE, CORN, AND POTATO INSECT CONTROL IN THE H
R. B. Workman, Assistant Entomologis
Insecticide recommendations change frequently. Use the
available. Discard old reports. Follow the safety precauti
label at all times. Make sure that agricultural poisons are
^ Septembb~ , 1964
ASV QS AREA \
n 3 icide
not^ home use.
CABBAGE INSECTS: Weekly treatments give the best insect control. Insects are
most damaging early and late in the season at Hastings when temperatures are higher.
Insecticide coverage is as important as the chemical used. Thorough coverage
means better control at less cost. Check it frequently. High dosages may leave
illegal residues on the harvested crop. Fewer wrapper leaves will reduce insecticide
residues on the harvested heads. Do not add excessive leaves to fill out the pack.
Cabbage aphids and loopers are difficult to control on older plants. Large
leaf surfaces protect aphids from sprays and systemic insecticides do not translocate
readily. Large leaf surfaces protect eggs, larvae, and moths of the cabbage looper.
Best coverage is needed at the inner and lower leaf area. Two nozzles overhead are
essential. Spreader-stickers will aid insecticide penetration at this time.
Spreader-stickers are not necessary when plants are small.
Green peach aphids are found on the bottom leaves. Sprays for cabbage aphids
and worms will give control. Disc cabbage under after the last cutting to prevent
migration to potatoes.
FOR CONTROL OF CABBAGE INSECTS IN THE HASTINGS AREA
Insect Insecticidel Amount i Minimum days Notes
(E=Emulsible) per acre before harvest
Dibrom 8E i 1 pt. 4 Fast, short activity.
Cabbage Parathion 4E j -1 pt. 7-- pt., 10-1 pt. Regular applications needed.
Phosdrin 2E 1 pt. 1 Fast, short activity.
SSystox 2E l pts. 21 Fast, long activity
DDT 2E plus 2 qts. + 14 & 30 14 days if leaves removed.
Cabbage Toxaphene 8E 1 qt. 30 days if leaves not removed.
Worms, Dib;0omi 8E 1 qt. 4 Effective on loopers.
s Parataion 4E 1 pt. 10 1 Excellent in 1964 looper tests.
Parathion 4E+ 1 pt. + 14 Fewer wrapper leaves gives
Toxaphene 8E 1 qt. lower residues.
i Phosdrin 2E 1-2 pts. 1 Higher dosage for loopers.
Mole Chlordane 8E
SPreplant soil treatment (spray).
i Preplant drench--4 oz. per 100
Sgals. per 1000 sq. ft.
One pint of Parathion 4E in 400 gallons of water per acre, as a drench, will give
rapid control of cutworms and mole crickets about cabbage seed beds or transplants.
Chlordane-Toxaphene baits are still effective against mole crickets.
CORN INSECTS: Chief corn insects at Hastings are budworms, earworms, stink bugs,
and various kernel destroying insects. High clearance sprayers are necessary for
effective control. Ensilage corn is cheaper to raise because fewer pesticide
applications are required. Insects attacking the ear are more difficult to control
and a long period of protection is necessary.
Insect Insecticidel Amount 'Days before Notes
(E=Emulsible) per acre harvest
Budworm, DDT 2E -2-4 qts. -- High dosages for earworms. Do not
Earworm Parathion 4E ;-1 pt. i 12 feed forage or ensilage treated with
Sevin 50W 3 lbs. 7 i DDT or Toxaphene to dairy animals or
Toxaphene 8E '1-2 pts. -- animals being finished for slaughter.
Stinkbug Use lower rates of above insecticides. DDT is not effective.
POTATO INSECTS: Aphids occur during the latter part of the season and will lower
yields if numerous. Do not rely on them to force maturity. Little insect damage
was found at the graders last year. Wireworms have not been a problem for several
years but should not be forgotten. Tuberworms seem to have disappeared. Cutworms
can be expected. Continue spraying up to a week before actual digging. Deeper
hilling will reduce cutworm and tuberworm injury, greening, and insecticide residues.
Endrin has not been withdrawn on potatoes by the FDA but use is risky as near-
excessive residues were common last year.
INSECTICIDES RECOMMENDED FOR CONTROL OF IRISH POTATO INSECTS IN THE HASTINGS AREA
Insect Insecticidel Amount Days before Notes
(E=Emulsible) per acre harvest
Aphids 1 Dimethoate 4E --1 pt. 7 Use 1 pt. of Dimethoate for
Systox 2E li pts. 21 heavy infestations.
Thiodan 2E 1 qt. no limit
Cutworms, Parathion 4E .1-1 pt. 5 Use 1 pt. of Parathion for loopers.
Plantbugs, Thiodan 2E 1i qt. no limit Spray up to 1 week of digging for
Tuberworm, i Toxaphene 8E ;1-2 pts. no limit cutworms and tuberworms.
Wireworm Diazinon AG500 1-2 qts. no limit Preplant soil application. Aldrin
Parathion 4E 72 qts. no limit is not cleared on potatoes.
Leafminer i May be numerous at harvest but rarely cause damage.
10ther formulations may be used if the amount specified is adjusted accordingly.
Emulsible insecticides generally give better control and are safer, easier to use,
and/or less expensive then other formulations.
Growers and suppliers should avoid pesticide contamination of containers and
storage areas for cabbage and potatoes. Insecticides spilled on a truck bed may
be a source of illegal residues. Keep records of pesticide applications for
*Revision of Mimeo Reports POL 64-3 & 64-4.