Je. Slosser et al., INFLUENCE OF PLANT MATURITY AND APPLICATION TIMING ON EFFICACY OF DICROTOPHOS FOR CONTROL OF COTTON APHID, The Southwestern entomologist, 22(2), 1997, pp. 207-215
Efficacy of dicrotophos for controlling the cotton aphid, Aphis gossyp
ii Glover, was investigated at the Texas Agricultural Experiment Stati
on at Chillicothe in 1992-1994. Cotton was planted in late April, late
May, and late June each pear, and dicrotophos, at 0.5 Ib Al/acre, was
applied as aphid numbers began increasing during August. A single app
lication was made at different aphid densities within each planting da
te. A treatment threshold of 35-50 aphids per leaf can be used for all
three planting dates. A single application prevented development of h
igh numbers for extended periods in the late April and late May planti
ng dates; in some years populations of 50 aphids per leaf did not deve
lop in these two plantings. Multiple applications will probably be nec
essary to control aphids in late June cotton.