Botrytis Blight - Closely spaced plants, overcast cloudy, rainy weather, and flower drop from overhead hanging baskets have lead to the development of Botrytis Blight on many different ornamental crops. 

Botrytis blight is best managed by combining proper sanitation practices with environmental controls and preventative fungicides applications.

·   Promptly remove infected plants, keep weeds under control, and place cull piles as far away from your greenhouse as possible. Keep garbage cans covered so spores are not released into the greenhouse via air currents.

· Water early in the day, so foliage can dry rapidly.  As plants are sold, provide more space to your existing crops to reduce humidity levels within your crops.  Reduce humidity by heating and venting several times in the evening and in the morning.

·  Apply preventative fungicides before cleaning up plants so spores are not released as workers handle plants.  On ornamental crops, a number of fungicides are labeled for use against Botrytis. The New England Recommendation Guide lists the following fungicides under Botrytis Management: Compass, Decree, 26GT, Daconil Weather Stik or Daconil Ultrex, Dithane Rainshield WF, Heritage, Medallion, Protect T/O, Terraguard or Sextant.  (Before treatment, read labels carefully to see if there is potential damage to flowers or if unslightly residues will be left).   

When disease pressure is high, growers often rely on Decree (a non-systemic fungicide with both protective and curative activity), Daconil or Sextant.  GT 26 and Sextant have also resulted in resistant Botrytis strains, so rotate among products to delay the buildup of resistant strains. There are also reports of widespread resistance to the benzimidazole fungicides (Cleary's 3336 and Fungo Flo).

Aphids, thrips, mites and broad mites continue to occur. See previous updates for more information.

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