Evaluation of Cultural Practices to Reduce the Incidence of Tomato Spotted Wilt Virus (TSWV) in North Carolina Peanut (Arachis hypogaea)

Abstract

Tomato Spotted Wilt virus (TSWV), a thrips-vectored virus, has recently become one of the most devastating pathogens of peanut (Arachis hypogaea) in North Carolina. North Carolina peanut growers saw a dramatic increase in infestations of TSWV in 2000. Certain cultural techniques in Georgia have shown to lessen the amount of virus, and these were evaluated to determine their effect on TSWV incidence. The production systems are discrete between the runner-type peanuts grown in GA and the virginia-type peanuts in NC, thereby requiring that these practices be evaluated in the NC. Treatments included plant populations, varieties, twin and single row plantings, reduced tillage, planting dates, and in-furrow insecticides. During the growing seasons of 2001 and 2002, treatments compared were plant populations of 7, 13, and 17 plants per meter of row; varieties Gregory, NC V-11, and Perry; twin and single rows; conventional tillage and strip tillage; early and late planting dates; and phorate and aldicarb. Research plots were scouted for visual symptoms of TSWV monthly in 2001, and weekly in 2002. In 2001, symptomatic plants were tested for presence of the virus using the ImmunoStrip test system (Agdia, Elkhart, IN). High plant populations had less virus than lower plant populations, Gregory was infected with less virus than either NC V-11 or Perry, twin rows had a lower amount of virus compared to single rows, preliminarily strip tillage has had less virus than conventional tillage, and peanut treated with in-furrow phorate had less incidence of virus than those treated in-furrow with aldicarb.