Floydada, Texas
February 6, 2004
Controlling early-season cotton
insects is one of the best tools producers can use to manage
their crop for early maturity and harvest, according to a Texas
Cooperative Extension cotton entomologist.
"We need to protect the crop up through squaring, so we need to
scout for early-season pests on a regular basis," said Jim
Leser, Extension cotton entomologist based at Lubbock. "Before
you spray, ask yourself...will it pay? Timing is everything in
making an insecticide application work, and in making more
profit to cover the application cost."
Leser was one of eight featured speakers at the Jan. 28 Caprock
Cotton Conference here. More than 100 producers attended the
conference for updates on cotton insects, weevil eradication,
national and state legislation, alternative crops, crop water
use efficiency and market prices.
Thrips are one of the most important early-season pests to watch
for in irrigated cotton. Growers seldom increase yields by
controlling thrips in dryland fields where water is a limiting
factor, the entomologist noted.
"Western flower thrips are the chief culprit on the Texas High
Plains. Their feeding damages both leaves and squares on the
plant. Research studies have shown that we can boost yields by
as much as 21 percent if we control early-season thrips," Leser
said. "We can achieve good control by putting Temik down at
planting. Or we can make one or two later applications of
Orthene, Bidrin or dimethoate -- as thrips move into the field.
"Foliar insecticides are a good, cost-effective choice for
thrips control – especially in narrow-row cotton. Foliar
applications should based on the number of mature and immature
thrips in the field, and timing is crucial since thrips
generally disappear once the plants set squares."
Selecting varieties with insect resistance can also help offset
damage from early-season pests. Bollgard and Bollgard II
varieties seem to hold up very well against pests such as
bollworms and caterpillars, Leser said.
Lygus bugs can threaten late-planted, stress-susceptible cotton
if the field borders areas where mustard, thistle and alfalfa
are growing. Lygus bugs live in these plants and in road-side
weeds during the spring. In summer, sunflowers and sweet clover
also harbor this pest. When young cotton plants emerge nearby,
Lygus bugs move from these host plants into cotton, he added.
"Lygus bugs feed on cotton squares and immature bolls, so we
must watch for them and be prepared to apply a control treatment
up through squaring and boll initiation. Their damage potential
declines once the plants accumulate 350 heat units after the
first white flowers appear," Leser said.
Growers who plant stress-tolerant varieties, manage their crop
for early fruit-set, and aggressively control early-season
insects pests will come out ahead at harvest, he added.
"Early squares make our lint crop, so we have to protect against
insect damage right up through squaring and flowering. Managing
for early plant maturity and protecting plants from early-season
insects also makes the crop less vulnerable to later-season
boll-feeding insects," Leser said. "Spraying late is not
profitable.
"Regardless of which pests they face, growers who base control
decisions on a realistic target yield, and then spray to make
money instead of simply spraying to eliminate pests, will come
out ahead."
Brand names appearing in this article are used for product
identification. No endorsement is intended, nor is criticism of
similar products not mentioned.
Writer: Tim W. McAlavy, (806)
746-6101, email:
t-mcalavy@tamu.edu |