Stockbridge Technology Centre in Yorkshire, England was responsible for conducting trials to determine if UV-C light could be successfully incorporated into an Integrated Pest Management Strategy in basil crop production. Many varieties of basil suffer from infection with Peronospora belbahrii, which causes basil downy mildew and was the primary subject of our UV-C investigations.
With a dose of up to 67.1 mj/cm2, applied three times a week and followed with a night-time darkness period, there was no consistently significant efficacy against disease progression observed. We also looked at the effect of UV-C light on controlling aphid infestations, and we noted a general trend towards a higher population of aphids following UV-C exposure. This has led us to hypothesise that in basil the UV-C treatment may induce a physiological or morphological change to the plants, or to aphid physiology, that may act to support the populations of this particular pest.
Although UV-C does not appear to be a viable option in basil crop production, we remain busy supporting project partners. This year, STC will be looking into running some laboratory-based trials on UV-C for the control of Tomato Russet Mite, which is a major problem for our growers.
Figure: Basil Downy Mildew (Peronospora belbahrii) on basil.