Tomato Spotted Wilt Virus: TSWV of Peanut: Factors
TSWV of Peanut
Plant Population
Infection of an individual peanut plant with tomato spotted wilt virus is of greater probability among sparse plant populations than among dense populations. Establishing higher plant populations does not appear to reduce the number of infections in a particular field, but likely reduces the percentage of plants that are infected. Field surveys in Georgia in 1992 indicated a substantial reduction in the percentage of plants infected with spotted wilt as plant density increased from <2 to 2-4 to >4 plants/ft. of row. Gorbet and Shokes found corresponding increases in incidence of spotted wilt as plant populations decreased in Florida.
While some inconsistencies in plant population effects have been reported, the overall consistency of plant population effects and the magnitude of those effects have increased as spotted wilt epidemics in Georgia became more severe. The establishment of uniform stands of >4 plants/ft. of row has been recommended for minimizing losses to spotted wilt. The actual seeding rate required to achieve this population has been a function of seeding rate in conjunction with seed quality, soil moisture, soil temperature and planting depth.
Establishing an even stand of rapidly emerged and vigorously growing young plants helps reduce the risk of losses to TSWV. Stands of at least four plants per foot of row with no skips should be established.
An index has been developed to quantify the relative risk of spotted wilt and the reduction of risk of losses to spotted wilt with the use of the factors previously discussed.