Estimation of the effect of Tomato spotted wilt virus (TSWV) infection on some yield components of tomato

The effects of Tomato spotted wilt virus (TSWV) on yield and quality of tomato fruits were studied from May through November of 2004 at the Experimental Field of the Agricultural Faculty of Ondokuz Mayis University, in Samsun province, Turkey. TSWV caused 42.1% and 95.5% reduction in yield and marketable value of tomato, respectively. TSWV infection in tomato crop caused significant (P < 0.05) reductions in weight, total number, width and length of the fruits in infected plants. Reductions in yield-contributing parameters were 26.61% in weight, 20.18% in number, 10.94% in width and 11.93% in length of fruits. It is difficult to estimate the actual yield loss and influence levels of TSWV in the field. Economic data are scarce, but in the present study it was estimated that the yield loss due to TSWV in tomatoes was approximately $0.9 million in Samsun, Turkey.