Response of processing tomato varieties to TSWV under Fresno County, California conditions

• Published in: Phytopathology Vol. 99; no. 6; p. S131
• Main Authors: Turini, T, LeStrange, M, Gilbertson, R
• Format: Journal Article
• Language: English
• Published: 01.06.2009
• Subjects: Lycopersicon esculentum; Tomato spotted wilt virus
• ISSN: 0031-949X

Tomato spotted wilt virus has caused substantial losses in California processing tomatoes. Use of available TSWV-resistant varieties is limited because few have yield or quality comparable to commercial standards. The objective of this study was to compare susceptibility of processing tomato varieties to this virus. In three 4 replication randomized complete block trials, 13 mid-maturity processing tomato varieties were evaluated at the University of California West Side Research Center in Fresno County in 2008. Entries included AB 2, AB 8058, H 2005, H 2601, H 4007, H 8004, H 9780, HM 6898, NDM 5578, NUN 672, PX 1723, SUN 6368 and UG 4305. Trials were transplanted on 16 Apr and 13 May and one was direct seeded on 13 May. The number of plants expressing TSW-symptoms was recorded one to three days before harvest in each one bed by 21.3 meter long plot. Representative samples were tested with TSWV immunostrips. Highest percentage of TSW-symptomatic plants was 20, 16 and 11 in 16 Apr and 13 May transplant, and 13 May direct seeded trial, respectively. Variety AB 8058 has genetic resistance to the virus (SW5 gene) and incidence was very low. Incidence in Sun 6368, without SW5 gene, was similar to AB 8058. Other entries with consistently low incidence included H 2005, H 4007 and UG 4305. Knowledge of relative susceptibility of processing tomato varieties is important for those making management decisions regarding TSWV in this production area.