Albert Culbreath is a research plant pathologist for the University of Georgia at the Tifton campus. He has worked for the university for thirty years and works largely on leaf spot diseases caused by a couple of fungal pathogens and tomato spotted wilt virus. He feels that a lot of progress has been made in terms of managing tomato spotted wilt virus. A lot of the success has come from breeding programs. The resistance in the varieties available has improved dramatically over the last thirty years.
He feels as if it is a bit of a mystery but for whatever reason tomato spotted wilt virus has been on the increase in recent years. In fact, the pressure that farmers are seeing in 2022 is the heaviest the industry has seen in roughly 20 years despite the better resistance and integrated management that farmers are practicing. The issue does present an opportunity for Culbreath’s research standpoint to evaluate more varieties and more breeding lines and see how they stack up and how farmers can best use them. In addition to that, what we can combine with those varieties to improve disease control. There is not any immunity in any of the cultivar lines. However, the variety Georgia-12Y has remarkably better resistance than Georgia-06, which is still our predominant variety. Even with the best resistance we have in a year like 2022, especially with early planted and such, that’s just not enough.
One of the factors researchers have worked with for years is Phorate and Thimet insecticide. The tomato spotted wilt virus is spread by thrips and they have not seen many insecticides at all that provides a consistent suppression of tomato spotted wilt virus. Despite the thrips control, Phorate or Thimet is the exception to that for whatever reason in the 2022 year. Researchers have seen a larger response to Thimet than what has been seen in quite some time. There is still extremely heavier pressure, but for whatever reason, a large response to the Thimet insecticide is being seen.