A2B-Lancasler Farming, Saturday, May 4, 1991
NEWARK, Del. This may
be a year for high populations of
com rootworms and white grubs,
according to Joanne Whalen, Uni
versity of Delaware Cooperative
Extension integrated pest manage
ment specialist. High populations
could mean economic diunage to
the com crop.
“The potential for com root
worm problems has been relative
ly low because of soil types, cli
matic conditions and crop rota
tions,” Whalen said. “But we
found relatively high levels of
com rootworm adults in 1990.
This could result in an increased
potential for problems in continu
ous com planted in New Castle
County and northern Kent County
in 1991.”
The specialist warns that over
wintering levels of white grubs are
higher in both single-cropped and
double-cropped soybean rota
tions. Making an extra effort to
scout for these pests can help keep
the population under control.
In addition to white grubs and
com rootworm, Delaware farmers
should keep an eye out for seed
com maggots, wireworms and
cutworms. The population size of
soil insects depends on a number
of factors, including crop rotation,
soil type, tillage, cover crops and
spring weather conditions.
Following is a list of soil insects
and conditions favorable for an
outbreak.
• Seed com maggot cool
and/or wet springs when germina
tion is delayed; warm weather in
late winter will yield early fly
emergence and egg laying before
tillage operations; early-planted
Rootworm Damage Possible In Del. Corn
fields with poor drainage, high
crop residues and/or where high
rates of manure were applied.
• White grubs old sod, pas
ture, hay or set-aside acreage;
small-grain/soybean stubble or
full-season soybean stubble fields
with a heavy grass infestation the
previous year (adult beetles are
attracted to flowering grains and
grasses).
• Wireworm high organic
matter, sod covers and heavy grass
pressure in the previous season’s
crop.
• Cutworms late-planted
com black cutworm; early
planted com, dingy and variegated
cutworms; poorly drained soil,
heavy broadleaf weed growth,
soybean stubble from the previous
season and reduced tillage.
• Com rootworms continu
ous com planted on heavier soil
types (hot, dry soils are abrasive to
rootworm larvae), rotated fields
planted on heavier soils where
corn follows soybeans with a
heavy infestation of volunteer
com or weeds, or after a weedy
small-grain field.
“Being aware of the favorable
conditions for pests can help you
keep on top of a potential prob
lem,” Whalen said. “Scouting
your fields for these pests helps
you prevent economic losses.”
To detect white grubs and
wireworms, take soil samples
about two to three weeks before
planting, when soil temperature at
6 inches is 40 degrees Fahrenheit.
Take the samples before the land
is tilled.
At each site, sample a one
square-foot area of soil dug 6
inches deep. The quickest and
most effective way to sort through
the soil is with your hands. A
minimum of 1 sample should be
randomly taken for every 10 acres
but no less than 5 samples per
field. The treatment threshold for
Association Honors
HAMMONTON, NJ. The
Pesticide Association of New
Jersey recently awarded the Dis
tinguished Service Award to Don
Baldwin for his outstanding ser
vice to the agricultural chemical
industry.
After serving in the medical
department of the United States
Navy and the U.S. National Insti
tutes of Health, Baldwin entered
George Washington University,
where he received a bachelor of
science degree in zoology. He
then went on to the University of
Maryland Graduate School, where
he studied animal physiology and
biochemistry.
Baldwin’s career began at Dow
Chemicals (now DowElanco) in
1956. In 1968 he gave the import
business a try, calling it “fun but
not too profitable." Baldwin went
back to Dow in 1970, where he
worked in marketing until he
became involved in technical ser
vice and development in the
Northeast in 1975. He continued
to work at Dow until his retire
ment in december of 1990.
Some of his distinguished
accomplishments include moving
Dow from a com, cotton, and soy-
bean agenda to a broader market
view, including horticultural
crops,
grubs and/or wireworms is 1 per
square foot of soil.
Soil sampling is not effective
for detecting potential cutworm
problems. A preventive treatment
should be used only in high-risk
fields. These fields should still be
Don Baldwin, left, receives the Pesticide Association of
New Jersey’s Distinguished Service Award from Henry
Rupp, association president. Baldwin was recognized for
his outstanding service to the agricultural chemical
Industry.
In addition to his accomplish- the Entomological Society of
ments, Baldwin has been an active America and the Northeast Weed
member of the northeast branch of Science Society.
scouted since a rescue treatment
may be needed.
Scout fields on a weekly basis
for small, irregular holes in leaves
or cut plants. On 1- to 2- leaf stage
com, consider a treatment when 2
(Turn to Page A3B)
Baldwin