Late-season damage to soybeans by threecornered alfalfa hopper (Homoptera: Membracidae) adults and nymphs
Fields tests were conducted in 1983 and 1984 to determine effect of lateseason feeding damage by adults and nymphs of the threecornered alfalfa hopper, Spissistilus festinus (Say), on yield of soybeans, Glycine max (L.) Merrill. Damage and subsequent yield reduction caused by S. festinus were partitioned into damage caused by nymphs versus adults by controlling the second generation on soybeans at different stages in its development. In 1983, yield reductions averaged ca. 342 kg/ha, with the nymphs responsible for 46.4 ¦ 16.7 percent (¦SEM) of the reduction. In 1984, yield reduction of 134.5 kg/ha occurred although S. festinus populations reached only 60 percent of the current threshold, indicating a need modify the threshold level. Proper timing of control measures, possible effect of reinfestations, cause of yield reduction, and the need to modify sampling strategy and the threshold to account for damage by nymphs are also discussed
| Main Authors: | , |
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| Format: | biblioteca |
| Published: |
1987
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| Subjects: | GRANOS, SOJA, HOMOPTERA, PERDIDAS, RENDIMIENTO, SPISSISTILUS FESTINUS, |
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