INTERRUPTION OF THE NIGHT PERIOD BY UV-B SUPPRESSES POWDERY MILDEW OF ROSE AND CUCUMBER
Experiments were conducted to determine the optimum dose of UV-B (280-315 nm) required for suppression of powdery mildews of rose (Rosa × hybrid) and cucumber (Cucumis sativus). Daily exposure to UV-B during dark at 1.2 W m-2 for 2 to 5 min substantially suppressed powdery mildew in Toril pot roses without measurable damage to the plants. Compared with the non-UV-B treated control, mildew severity nine days after inoculation was reduced by a factor of 2.6 or 51 times after daily exposures of 2 or 5 min, respectively. In Confida cucumber, the optimum exposure time to suppress powdery mildew was 5 to 10 min. Brief night time exposure to UV-B may provide a non-chemical option to suppress powdery mildews in greenhouse crops, where such pathogens have been historically problematic, and fungicide resistance problems are a continuing challenge.
Suthaparan, A., Torre, S., Mortensen, L.M., Gislerød, H.R., Stensvand, A., Solhaug, K.A. and Gadoury, D.M. 2012. INTERRUPTION OF THE NIGHT PERIOD BY UV-B SUPPRESSES POWDERY MILDEW OF ROSE AND CUCUMBER. Acta Hort. (ISHS) 956:617-620
Cucumis sativus, powdery mildew, Rosa × hybrid, UV-B radiation