Hormetic UVC Treatments for Control of Plant Diseases on Protected Edible Crops
Plant diseases account for annual losses of 8-15% depending on crop species, and over recent years there has been pressure to replace chemical interventions for disease control with alternative strategies. The protective effects of short wavelength ultraviolet light (UV-C) treatments, which are believed to work by inducing plant defence responses, have been known about for >20 years, and have been shown to induce resistance against a range of pathogens pre and post-harvest on tomato. New types of pulsed UV-C delivery systems allow the necessary doses to be applied in seconds, opening up prospects for commercialisation of the treatments. In this project, we aim to undertake glasshouse trials and commercial testing, using two protected edible crops, tomato and lettuce, to determine the optimum UV-C treatments for control of a range of commercially important plant diseases. Treatments will include varying timings, intensities and frequencies of applications, and will also examine the effects of the treatments on agronomic properties of the crops such as enhanced shelf-life (tomatoes) and greenness (lettuce). The effects of the treatments on general microbial populations on leaves (i.e. on potential beneficials) will also be examined. The outcomes will be the establishment of treatment regimes that offer optimal protection against diseases of lettuce and tomato, along with the establishment of practical strategies for commercial applications of these treatments, and these will be provided as advice to growers.