Integrated management of viral tomato diseases in Southern Italy

Tomato spotted wilt virus (TSWV) vectored by thrips, Cucumber mosaic virus (CMV) and Potato virus Y (PVY) vectored by aphids are among the most serious threats for tomato cultivation in Southern Italy. Insecticides applied on a calendar schedule for insect control are not effective in preventing the diseases progress. A field experiment was conducted to determine the separate and integrated effects of UV-reflective mulch (UVRM), Acibenzolar-Smethyl (Actigard) and insecticides for the management of vectors and tomato viral diseases on tomato. UVRM. standard black mulch, and uncovered plots as control were the three main plots treated with Actigard and insecticides, both alone or in combination. Disease incidence was measured as percentage of TSWV infected plants and with the percentage of ELISA positive plants for the three viruses. The UVRM alone was effective in reducing disease incidence both for aphid transmitted viruses and for TSWV and a synergic effect of Actigard with UVRM was observed against the three viruses too. By contrast, the use of the insecticide alone did not result in a reduction of disease incidence of the three viruses on UVRM, while in the black mulch covered and uncovered plots a reduction in CMV and PVY disease incidence due to insecticide applications was significant.