Performance of Tomato Cultivars Under Natural Tomato Yellow Leaf Curl Disease (TYLCD) Pressure in Georgia, USA.

The severity of tomato yellow leaf curl disease (TYLCD) caused by tomato yellow leaf curl virus (TYLCV) in commercially grown tomato cultivars has been increasingly exacerbated in recent years in the southeastern United States. Four research trials were conducted over two consecutive fall seasons in the years 2022 and 2023 to assess the performance of tomato (Solanum lycopersicum L.) cultivars introgressed with single (Ty-1) or combinations of (Ty-3 and Ty-6) resistance gene(s) in Georgia, USA. In 2022, studies were conducted on a commercial farm in Colquitt County and a research farm in Tift County. In 2023, experiments were performed on a commercial farm in Grady County and a Tift County research farm. Tomato cultivars (cv.) with an intermediate resistance to tomato yellow leaf curl virus (TYLCV-IR), including Camaro, Grand Marshall, Jolene, Red Snapper, STM 2255, and Varsity, were compared to the TYLCV-susceptible (TYLCV-s) cv. Myrtle. This study evaluates the total produced yield of tomato cv. under natural disease incidence, severity, relative maturity and marketable yield. Our findings suggest TYLCV-IR cv. STM 2255, Jolene and Grand Marshall, except Red Snapper, had a lower virus incidence compared to cv. Myrtle. Moreover, cv. Red Snapper, Varsity and Camaro exhibited moderate disease progression in our research plots. The cultivars Grand Marshall and Jolene had significantly lower TYLCD severity than Myrtle. Furthermore, fruit yields per plant were highest for Camaro, Grand Marshall, Jolene, and STM 2255. Overall, Camaro, Grand Marshall, Jolene, and STM 2255 performed the best based on moderate-to-low TYLCD incidence and severity, and superior yield among the evaluated tomato cultivars. Therefore, identifying the most resistant/tolerant and environmentally suitable cultivars is needed to mitigate the viral disease in tomatoes.