Peanut Cultivar Response to Tomato Spotted Wilt over Five Planting Dates

Abstract

ABSTRACT Tomato spotted wilt virus (TSWV) is vectored by thrips and causes an economically damaging peanut disease in the southeastern U.S. Peanut planting was traditionally initiated when soil temperatures became favorable in April. Planting in the latter two thirds of May is recommended to avoid thrips feeding and reduce tomato spotted wilt (TSW) incidence. This regime concentrates work load for growers and buying points, increases risk of tropical storm damage during harvest, and may contribute to reduced crop maturity. Improved TSW tolerance in cultivars may allow growers to plant earlier spreading risk and work load. Cultivars Georgia Green, Georgia-03L, AT 3085RO, and Flavor Runner 458 were compared with the advanced breeding line EXP 271516 based on peanut foliar condition, pod yield, and grade in 2008 and 2009 in Dawson, Georgia and Headland, Alabama. Peanuts were planted at five planting dates starting in late April through early June each year. Disease incidence was variable according to year, location, and planting date. Planting dates in April and early May resulted in higher TSW incidence. Foliar TSW ratings for the susceptible cultivar Flavor Runner 458 ranged between 48–96% at harvest. Georgia Green had 10–65% TSW incidence while maintaining yields between 3,315–5,440 kg/ha. Other cultivars had better TSW tolerance resulting in higher yield under more intense TSW pressure. Planting in the middle of May or later resulted in the highest yields. Cultivars with improved tolerance to TSW maintained yield above 4,490 kg/ha in early plantings. These results indicate the least risky management is possible by planting the most TSW tolerant genotypes during the current recommended planting dates.