Investigating the effects of planting date and Aphis gossypii management on reducing the final incidence of cotton leafroll dwarf virus
John W. Mahas, Fredericka B. Hamilton, Phillip M. Roberts, Charles H. Ray, Gary L. Miller, Murray Sharman, Kassie Conner, Sudeep Bag, Eugene K. Blythe, Michael D. Toews, Alana L. Jacobson
Abstract
This is the first study to research management strategies for cotton leafroll dwarf virus (CLRDV) in the southeastern U.S. The efficacy of aphid vector management to reduce final CLRDV incidence was investigated concurrent with efforts to monitor aphid population dynamics and timing of CLRDV spread. Adjusting the planting date and insecticide applications did not reduce the final incidence of CLRDV, which was confirmed in 60–100% of plants per plot using RT-PCR. Aphid population density was reduced, but not eliminated with foliar insecticide applications. Aphis gossypii was the only species observed on cotton and was the dominant species collected in pan traps. Three distinct periods of virus spread were detected with sentinel plants including early, mid-and late-season. Most virus spread occurred during large aphid dispersal events.