AGRICULTURAL RESEARCH CENTER, HASTIiGq,CJ~ELOcglpl Ei
Hastings ARC Research Report 1981-7 September 1981
SEP 2 1981
POTATO INSECT CONTROL IN THE HASTINGS AREA
NOTES ON ONION PRODUCTION.
R. B. Workman, Assoc. Entomoibgist n' Of Florid
FOLLOW ALL DIRECTIONS FOR USE AND SAFETY ON THE PESTICIDE LABEL AT ALL TIMES.
Potato Insecticide Amount Cutoff Notes
insects (E-Emulsible) per acre-aa (days)
Azodrin 5E 13 oz. 7 Aphids on potatoes are resistant
Dimethoate 2.67E 1 1/2 pts. None to Parathion, Phosdrin, and
Aphids Lannate,Nudrin 90S 1/2-1 lb. 14 Thiodan. Pirimor has been with-
Meta-Systox-R 2E 1 1/2 pts. 7 drawn from the market.
Monitor 4E 1 pt. 14
Systox 2E 1 1/2 pts. 21
Azodrin 5E 13-26 oz. 7 Hilling deeper protects tubers
Armyworms, Lannate,Nudrin 90S 1/2-1 lb. 14 from cutworms and greening. Only
Cutworms, Monitor 4E 1-1 1/2 pts. 14 Lannate or Nudrin will control
Tuberworm, Parathion 8E 1/2 pt. 5 beet armyworm (black dot over
Other Phosdrin 2E 1 qt. 1 2nd pair of legs). Monitor
Cater- Pydrin 2.4E 2.7 oz. 7 controls Colorado potato beetle.
pillars Thiodan 2E 1-2 qts. None
Leaf-footed Guthion 2E 1 qt. 7 Feeding is, generally, on flower
Plant Bug Parathion 8E 1/2 pt. 5 stems. Damage to plant is likely
Green Phosdrin 2E 1 pt. 1 very low. Guthion is effective
Stinkbug Thiodan 2E 1-2 qts. None on tuberworms.
Wireworm Diazinon 4E 1-2 qts. None Preplant soil treatment. Not a
Parathion 8E 1 qt. None problem for several years.
Leafminer May be numerous at harvest, but rarely cause damage.
a/ Adjust dosage for other formulations (2E, 4E, 8E, WP, etc.).
Pydrin: Registered on potatoes for potato aphid, potato tuberworm, tarnished plant
bug, and Colorado potato beetle. It is highly effective on many insects and has an
emergency exemption on cabbage in Florida. Control of insects occurring in cool-
moist soils or dense leaf cover may be erratic as it appears that exposure of poi-
soned insects to sunlight, dry soils, and predators adds to the effectiveness of the
product. Sprays during the late afternoon or evening may not be as efficient as
Aphids: Not a recent problem. Regular pesticide treatment is not needed as formerly
and may reduce numbers of parasites and predators. Low numbers of aphids will not
injure plants kept in good growing condition. Tiny wasps (light-colored, swollen
aphids), lady beetles, and certain flies feed on the aphids. Large numbers of these
insects indicate that aphid numbers are declining. If aphid numbers increase and
begin moving to the tops of the plants spray weekly until numbers decline. Use good
coverage. Spreader-stickers will help. If controls fail, doubled rates or nonrecom-
mended pesticides will not help. The outbreak will decline in time.
SCutworms: Damage usually occurs on greened tubers which have been exposed to the soil
K surface by inadequate covering, cracks in the soil, or rains. Cutworm eggs are laid
on plant parts near the soil where the cutworms feed first. Most activity above the
soil surface is at night. Control is very difficult after the cutworms begin feeding
on tubers beneath the soil, however, most greened tubers are graded out.
Molecrickets: Damage is common in some areas. Tunnels are similar to those of cut-
worms but penetrate deeper into the tubers and occur at all soil depths. Control is
not promising as molecrickets fly into potato fields and treatment is difficult.
Beet armyworm: Numbers build up on pigweeds then move to potatoes. Color varies
from light green to black. The black dot over the 2nd pair of legs identifies the
beet armyworm. i
STuberworms: Usually present in area but common only during hot-dry seasons. Tunnels
spread out or penetrate into the tuber and have a lining which can be cut out from
the tuber. Tuberworms can be a problem in eggplant or in potatoes stored during the
summer--pinkish-gray worms which wiggle vigorously when touched and slender gray moths
about in. long. Dispose of all stored potatoes in advance of planting to reduce
populations. Tubers exposed by rains or cracking of soils allow tuberworm access.
Wireworms: Not a problem for many years. When damage occurred in the 60ies, about
7 wireworms, 5/8 in. long and shiny yellow, could be found per square foot in the
top of the rows. Numbers have been low since that time. "Wireworm" damage is most
common in dry fields and may also be caused by tuberworms or nutgrass.
ONION PRODUCTION NOTES
Yields: Tests in cooperation with Dr. J. R. Shumaker showed that a yield potential
of onions at Hastings could range upwards of 500 cwt/A. Cultivars tested this
Cultivar Yield cwt/A % bolted
Granex 429 496 4.4
Henry's Special 484 18.6
Texas Grano 502 481 7.5
Dessex 437 16.4
Ringer 364 21.0
Ring Gold 363 29.0
Golden 266 36.8
Early Yellow Premium 186 9.0 (Bulbs very small)
There were 13 days where 320F or below was recorded (mostly in the upper 20ies) and
1 day of 150F.
Acreage of Vidalia onions in Georgia last season was about 4000 A. with about 1.5
million 50 lb. bags produced. Chief cultivars are Yellow Granex, Granex 33, and
Texas Grano 502.