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There were 10 million acres of cotton harvested in 1987 with an average yield of 1.5 bales/acre (Table 1). This amounted to 14.7 million bales of cotton being produced by USA growers. These figures reflect an increase of 644 thousand harvested acres compared to 1986, but, more importantly, average yield per acre was increased by 0.4 bale. Consequently, 4.9 million more bales of cotton were produced in 1987 than in 1986. The leading cotton-producing states were Texas, California, and Mississippi. Arthropod pests reduced yield by 5.9% in spite of the best control measures (see tables 2a to 2ee). This amounted to a loss of 856 thousand bales from potential yield costing an estimated $246.5 million in revenue. The beltwide cost per acre for controlling arthropod pests was $31.89, which reflected an increase of $7.19/acre over 1986. The total cost for controlling insects (Table 2a) was $316 million. The estimated total cost of arthropod pests to USA cotton production was $562.5 million. Increased insecticide control costs per treated acre may be attributed to increased severity of the boll weevil, Anthonomus grandis Boheman, and consequent increased number of applications required (42% greater) and cost per application (17% greater). The cost per application for Heliothis (bollworm/tobacco budworm) increased (12%) as well, and this probably reflected the expanded use of mixtures to control this pest. Boll weevils caused more damage in 1987 in spite of control measures than did Heliothis, but the total dollar cost was greater ($215 vs 189 million) for Heliothis because of the greater cost per application. Lygus bugs were less important as pests in 1987, but they were probably controlled incidental to the foliar-applied treatments for weevils during early season as well as by the widespread usage of aldicarb, in-furrow, at planting. Other pests cited as significant included aphids (beltwide) and stinkbugs in the Carolinas. Resistance to pyrethroids in the tobacco budworm (TBW) Heliothis virescens (F.), was recorded in Texas, Arkansas, Louisiana, Mississippi, and Alabama, but not in the Carolinas, Georgia, and western states. TBW populations were relatively high in June but declined precipitously thereafter. A pyrethroid-resistance management program was successfully implemented and near complete compliance was noted in the use of materials other than pyrethroids for controlling first generation Heliothis in cotton. |
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©National Cotton Council, Memphis TN |
Document last modified Sunday, Dec 6 1998
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