UV-Reflective Mulch and Chemical Resistance Induction for the Control of Tomato Yellow Leaf Curl Disease in Greenhouse Tomato Crops

The purpose of the present study was to evaluate new control measures against Tomato yellow leaf curl disease, alternatives to control methods conventionally applied in greenhouse tomato crops. We have examined the separate and combined effects of UV-reflective mulch (UVRM) and repeated applications of acibenzolar-S-methyl (ASM), a chemical elicitor of systemic acquired resistance, and compared the results with an untreated control on white mulch. In the ASM treated plots, different application doses were tested, applied at one-week intervals. The use of UVRM significantly reduced TYLCD incidence compared to the control. A significant reduction in TYLCD incidence was also observed in the plots treated with ASM. No significant difference was detected among the ASM application dosages. Nevertheless, weekly ASM sprays at a dose of 1 mg a.i. per plant seemed to induce a more effective plant defence response under high infection pressure. Compared to the untreated control on white mulch, the most significant reduction in disease incidence was observed using a combination of UV-reflective mulch and ASM (-42% at eight weeks after planting).