IMPACT OF TRANSPLANTING DATE AND THRIPS (HOMOPTERA: THRIPIDAE) CONTROL PRACTICES ON THE INCIDENCE OF TOMATO SPOTTED WILT VIRUS AND ARTHROPOD PESTSIN FLUE-CURED TOBACCO.

Authors: MCPHERSON, R - UNIVERSITY OF GEORGIA; CULBREATH, A - UNIVERSITY OF GEORGIA; Stephenson, Michael; Jones, David

Submitted to: Tobacco Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/23/1995
Publication Date: N/A
Citation: N/A

Interpretive Summary: Field studies using flue-cured tobacco in 1991 and 1992 were used to evaluate early and late transplanting dates and six insecticide treatments for the control of thrips, aphids, and tomato spotted wilt virus. The early transplant date showed larger thrips populations in 1991 with no effect in 1992 and neither the late or early date affected aphid populations or the incidence of tomato spotted wilt virus, but early planting date increased leaf yields. Only in 1992 did the foliar sprays reduce the infection of tomato spotted wilt virus and in both years reduced populations of both aphids and thrips but none of these treatments compared to the checks, increased yield or quality. Transplanting date or weekly insecticide treatments are ineffectual and uneconomic in the treatment of tobacco for control of tomato spotted wilt virus.

Technical Abstract: Field studies were conducted in Georgia flue-cured tobacco, Nicotiana tabacum L., during 1991 and 1992 to evaluate the effects of transplanting date and six insecticide practices on the abundance of thrips, primarily Frankliniella fusca (Hinds), and tobacco aphids, Myzus nicotianae Blackman, the incidence of tomato spotted wilt virus (TSWV), and cured-leaf yield and quality. Thrips populations were higher on tobacco transplanted in late March or mid-April than on tobacco transplanted in late April in 1991, while no transplanting date effects were observed in 1992. A transplant water treatment (TPW) of acephate followed by 6 or 8 weekly foliar sprays of acephate and weekly foliar sprays without TPW were effective in reducing the seasonal population densities of thrips. There were no differences in the percentage of plants infected with TSWV (a disease vectored by thrips) among the control practices in 1991 and only weekly foliar sprays reduced TSWV in 1992. Transplanting date effects were not consistent for TSWV infection, with higher infection rates in the earlier plantings in 1991 and later plantings in 1992. Transplanting date did not affect the seasonal population densities of aphids either year. However, all of the thrips control practices reduced aphid population densities. There was a higher cured-leaf yield in the early-transplanted tobacco but no differences among the treatments. Neither transplanting date nor thrips control treatments affected tobacco quality.