R. Montandon et al., LATE-SEASON TERMINATION EFFECTS ON COTTON FRUITING, YIELD, AND BELL WEEVIL (COLEOPTERA, CURCULIONIDAE) DAMAGE IN TEXAS DRYLAND COTTON, Journal of economic entomology, 87(6), 1994, pp. 1647-1652
The plant growth regulator ethephon, Prep ([e-chloroethyl] phosphonic
acid), and the desiccant arsenic acid, Desiccant L-10, were evaluated
for their effects on late-season squares, green bells, and yield of th
e cotton, Gossypium hirsutum, cultivars, 'Lankart 511','Lankart Sel. 6
11', and 'TAMCOT CAB-CS', in a dryland cotton production system in 199
0 and 1991. Damage to squares and boils by the bell weevil, Anthonomus
grandis grandis Boheman, was evaluated in 1991. All cotton;cultivars
treated with Prep (1.26 kg(AI)/ha) and Desiccant L-10 (2.63 1(AI)/ha)
in September had reduced numbers of squares in October and November co
mpared with untreated cotton. Plots were harvested in early December a
fter a killing freeze. Both Prep and Desiccant L-10 reduced the number
of green bells and cotton squares damaged by boil weevils in all cult
ivars in October. Yield was not significantly reduced by either chemic
al in 1990 or in 1991. The late-maturing 'Lankart Sel. 611' had lower
yields across treatments in 1990 and in 1991 than the intermediate-mat
uring 'Lankart 511' and the early-maturing 'TAMCOT CAB-CS'. A single l
ate-season application of a harvest aid chemical for reduction of fall
food may help control bell weevils and reduce the need for fall insec
ticide applications in dryland cotton. Relevance of this research to t
he Texas Bell Weevil Eradication Program is discussed.