Tomato Spotted Wilt Virus

TSWV Risk Assessment and Current Levels

Assessing the risk of Tomato spotted wilt virus (TSWV) has been an important component of management for the last ten years. It has typically been divided into two parts:

Prediction: This refers to predicting the severity of TSWV based on field history, cultural practices and thrips vector populations coming out of weed hosts.

Mitigation: This refers to assigning values of risk reduction to specific pest management tactics that have been shown to reduce the impact of thrips and TSWV to the crop.

Peanut Risk Index : For peanut growers, a guide has been in place for several years that combines these two assessments into a single guide. This guide enables peanut growers to assess how various production and TSWV management practices affect their level of exposure to significant losses from TSWV. It advises growers as to their need to implement specific TSWV management tactics or combinations of tactics.

Vegetable Risk Index : The vegetable guide is currently under construction and will expand the concept used in the peanut system by providing an estimate of potential exposure of their crop to TSWV. This additional component will involve estimating the level of dispersing tobacco thrips from weed hosts (see concept figure below) using thrips counts in weeds, TSWV levels in weeds, and weather data in a prediction model. It will then allow the grower to examine how various management options, when used alone and in combination, affect their potential level of exposure. Finally, it will provide information on the costs associated with each management option.