Impact of planting date on the incidence of thrips and TSWV in high tunnel tomato production

A study was conducted to evaluate the impact of planting date on thrips populations and the incidence of Tomato Spotted Wilt Virus (TSWV), in a high tunnel tomato production system. Tomato seedlings were transplanted in the HT on February 22nd and April 15th, with another planned for August. Over the course of the project, ambient temperature, water use, and weekly growth, including plant height, stem diameter, time to first bud, first flower, fruit set, and ripe fruit, were recorded. Thrips were monitored weekly through visual checks of the plants, and sticky traps placed inside and outside the HT. Thrips were tested for TSWV by qPCR. Thrips populations were only controlled before the second planting date to observe population growth of thrips within the second planting date. Thrips were first detected March 29^th and grew slowly until the beginning of June, at which time the population quadrupled and steadily increased over the rest of June. Preliminary results indicate that the first planting date was exposed to significantly lower thrips populations, with no significant number of thrips until the week of April 5^th. Furthermore, viruliferous thrips were not detected until one week before the second planting date. In the first eight weeks after being transplanted, the first planting date used roughly 65 gallons or 29 percent less water than the second planting date. Preliminary results show that transplanting in February leads to lower insect populations, decreased water use, and less exposure to TSWV, compared to transplanting in April.