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Oklahoma State University Stillwater, OK |
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Oklahoma Alfalfa |
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Oklahoma State University Stillwater, OK |
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Oklahoma Alfalfa |
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FALL INFESTATIONS OF SPOTTED ALFALFA APHID |
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| Infestation levels of spotted aphids may continue to increase if dry weather conditions persist during fall. In established stands, plants may be killed and stands thinned even after the last forage harvest is taken. Temperatures are often high enough in fall that aphids can continue to complete generations in as little as 7-10 days. When conditions are favorable for spotted aphid development, and particularly if infestations have been present in late summer, stands should be scouted at 1-2 week intervals during fall to insure that stand loss does not occur. In new fall seedings, spraying is recommended if aphid numbers exceed 1-2/plant up to formation of the first trifoliolate leaf. In larger plants with several trifoliolates, sampling should be conducted by carefully brushing plants so that aphids fall onto the soil surface for counting. When numbers exceed 10/plant, insecticide should be applied. In established stands, insecticide should be applied if numbers exceed 30/crown. |
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| Richard Berberet,
Alfalfa Entomologist Department of Entomology and Plant Pathology Oklahoma State University |
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