INTERRUPTION OF THE NIGHT PERIOD BY UV-B SUPPRESSES POWDERY MILDEW OF ROSE AND CUCUMBER

A. Suthaparan, S. Torre, L.M. Mortensen, H.R. Gislerød, A. Stensvand, K.A. Solhaug, D.M. Gadoury
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
http://www.actahort.org/books/956/956_73.htm
Cucumis sativus, powdery mildew, Rosa × hybrid, UV-B radiation
English

Acta Horticulturae