A new approach for strawberry disease control

Abstract

Ultraviolet-C (UV-C) irradiation has been used on small scale to kill microorganisms in agriculture and for control of foodborne pathogens in food industries. However, the doses of UV-C (254 nm) irradiation required to reduce diseases on strawberry and other plants have caused phytotoxicity. Here we report a new approach demonstrating greater killing power of UV-C irradiation against fungal pathogens without damaging strawberry plants when UV-C treatment was followed by a specific dark period. Field trials also included applications of microbial antagonists twice a week. The dark period most likely prevented activation of the light-induced DNA repair mechanism in microorganisms and greatly increased the lethality of the UV-C. This approach allowed for a substantial reduction of the UV-C effective dose to kill the microorganisms on leaves, flowers and fruit, without damaging the strawberry plant. The application of microbial antagonists resulted in excellent colonization of strawberry plants which filled the microbial void after UV-C “sterilization” and provided a barrier for recolonization by plant and potential foodborne pathogens.