I removed seven more plants that have gradually gotten worse from that original bed of 45 grafted tomatoes. I know that others are infected just by the lack of vigor shown but they are hanging on for now and since I don't have any more replacements I will watch them for further deterioration before removing them. In the past I have had a few plants live for months with TSWV and still continue to produce without the nearby plants getting TSWV. I usually pull young plants showing definite signs of TSWV immediately but in my experience it doesn't help in the overall results.
From what I have been able to determine over many years of dealing with TSWV it seems that the bulk of the plants infected don't show any visible signs of the infection for anywhere from a week to a month after being stung by the infected thrips. The largest problem with this disease is during the early summer usually May and June with fairly light problems later in the growing season although I have had plants get it late into August but that is rare. I think they are blown in with the wind during those windy months but don't usually remain in the garden for long thank goodness.
This is turning out to be a really bad season for TSWV. Already one of if not the worst I have ever experienced. I have talked to a few other gardeners who grow heirlooms and they are also experiencing more cases of it than usual. Hopefully I set out enough plants that I will have enough remaining when this blight is over to have a decent year. I'll just continue to keep my fingers crossed and see what happens.
Bill
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