CONTROL OF GRAY MOLD (BOTRYTIS-CINEREA) WITH FILM-FORMING POLYMERS

Several film‐forming polymers reduced the amount of grey mould on various crops in a dew chamber and in a plastic house under natural conditions. The polymers Wilt Pruf, Biofilm and Colfix reduced germination of conidia and germ tube length of Botrytis cinerea. The most effective inhibition of linear growth of the pathogen on potato dextrose agar was obtained by Safe Pack and Biofilm. All polymers significantly reduced grey mould on detached leaves of Capsicum, Phaseolus, tomato, cucumber, rose and pelargonium. Grey mould on rose flowers was not controlled, apparently due to latent infection. The substances Biofilm and Vapor Gard were applied either alone or with chlorothalonil fungicide on cucumber plants in a commercial greenhouse. The polymers had no harmful effect to the host. Disease on senescing female fruits of cucumber was reduced by 46–67% with no additive effect to the mixture with fungicides. Stem infection also was reduced. Copyright © 1990, Wiley Blackwell. All rights reserved