Effect of seedling source on incidence of tomato spotted wilt in flue-cured tobacco
Tobacco seedlings from 16 different outdoor seedbeds in 11 counties in Georgia were assayed by ELISA for tomato spotted wilt virus (TSWV). Only one asymptomatic seedling out of more than 1,200 was positive for TSWV. Additional seedlings from the 16 sources were transplanted into fields in each of six different counties, and incidence of spotted wilt was monitored in all fields throughout the season. Significant (P<= 0.05) field location effects were found for final, cumulative incidence of spotted wilt, but no significant effects were found for seedling source of field location X seedling source interaction. There were no consistent differences in final, cumulative incidence of spotted wilt among transplant sources. However, across sources of seedlings, incidence of spotted wilt varied greatly among field sites, with average incidence for the six fields ranging from 2,3% to 12,7%. Final, cumulative spotted wilt incidence was affected more by field location than by t ransplant source.