Gray Mold of Vinca

Disease Information

Gray Mold

 Botrytis cinerea

Symptoms and damage

 Brown water-soaked spots on chrysanthemum petals and leaves. First symptoms usually are on outer, older florets. Later, a powdery grayish brown mass of fungal spores covers affected parts. Lower senescent leaves may rot, and if the fungus gets into the stem, it may girdle the stem.

COMMENTS on disease

The fungus survives in plant debris as sclerotia. Spores spread by overhead irrigation and by air, favored by high humidity and temperatures of 50°F to 70°F. Warm days followed by cool nights encourages condensation on flowers which favors disease development. Wounded or senescent tissue is most likely to be infected.


Cultural control

  • Provide good air circulation-space plants apart.
  • Remove and destroy affected leaves as soon as noticed. Dispose of all plant debris promptly.
  • Avoid overhead watering.

Chemical control Use as a foliar spray in conjunction with cultural control methods. Tank-mix and/or alternate products from different groups with different modes of action to prevent the buildup of resistant fungi.

  • AllBan Flo
  • BonideCaptan 50 WP
  • Bonide Fung-onil Multi-purpose Fungicide
  • Botran 75W
  • Captan 50 WP Chipco 26019
  • Copper-Count-N
  • Daconil Weather Stik
  • Decree 50 WDG
  • ExothermTermil
  • Hi Yield Captan 50 W
  • Mancozeb-

o    Fore 80 WP.

o    Pentathlon DF

o    Medallion WDG

  • Zyban WSB 

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