I was recently asked by a grower/sheller how to minimize tomato spotted wilt virus (TSWV)  in Valencia varieties. Use of Thimet/Phorate came up. The grower has been using imidacloprid (Admire Pro or generic.) One way to reduce TSWV is to use Thimet and it certainly helps to get away from imidacloprid. We typically do not have intense TSWV in NC like they have in the southeast, and we have good enough genetics in our Virginia market types to allow use of imidacloprid for thrips without increasing TSWV. However, the Valencia varieties do not have the genetics to withstand TSWV without some additional management. The risk index for TSWV is found in Dominic’s chapter in 2025 Peanut Information. The discussion there goes into more detail than I will here. Valencia varieties may not be listed.

Here are ways to stack things in your favor:

1. Use Thimet or Phorate, but make sure your calibration is spot on. On our coarse, sandy soils with low organic matter we can get phytotoxicity.

2. Get the seeding rate up to the maximum recommended rate. This might require twin row plantings, but get at least 7 plants per foot of row regardless of your planting pattern. 7 is for Valencia varieties. 5 is for Virginia market types.

3. Plant in mid to late May. Thrips numbers tend to be lower then and there is a direct relationship between thrips population and TSWV. We have been planting a little earlier in recent years. That increases our risk for both thrips damage and TSWV. Planting a Valencia variety in late April carries substantial risk for TSWV.