Ag Chat from 6/24/26: Tomato Spotted Wilt in Tomatoes
From our Field Crops/ Horticulture Agent , Matt Solomon

This year has been the most prevalent for Tomato Spotted Wilt Virus (TSWV) in the county. We normally do not see as much pressure as our neighbors in the East or in South Carolina & Georgia.

TSWV is a pathogen that can infect over 1,000 different crops, but especially those in the Solanaceae family such as tomatoes, peppers and tobacco. This disease is not soil borne but is transmitted through an insect called a thrip. Thrips are small slender insects (1-2 mm) and there are over 30 species of thrips alone in North Carolina with the Western Flower and Tobacco thrips being the vectors for the virus. As the larvae of thrips hatch and feed on the plant the pathogen is transmitted and then replicated as the thrip matures.

Plant symptoms when TSWV is present shows in the upper portion of the plant. Leaves will have black stippling margins or bronzing & peppers will have yellow ring pots throughout the foliage. If infected early in the growing season it usually results in total plant loss with fruit becoming withered and covered in brown splotches. If TSWV is present it is best to discard of those infected plants by burning to insure that the thrips cannot over winter in the crop debris. It is also best to have your plants checked by an extension agent or crop professional to diagnose TSWV as symptoms can be similar to other diseases.

Prevention & Management
-Use resistant varieties with the Sw-5 & Tsw genes. These will be listed on the seed tag of the seed you are looking at purchasing.
-In large field settings use imidacloprid at planting to suppress thrips
-Control weeds such as dandelions, sow thistle, chickweed, buttercup, and plantain. They harbor overwintering thrip populations
-If growing in a greenhouse, use thrip-proof screens on air intakes and curtains to prevent entry
-Use yellow sticky traps to monitor thrip populations to know when to make an insecticide application

Please contact the Caswell County Extension office with any questions.