Noticed a dry white substance on the leaves of bush beans that survived freeze in Central FL. On cucumber plant. Used super thrive after freeze to help plants thru trama. Is this a fungus or residue from super thrive. Only a few plants are affected. |
If the white substance is only on the tops of the leaves and it is dry, it probably is a residue. If it is soft or if you can scrape it off the leaves with your fingernail, it may be powdery mildew. If so, you can pick off all the affected leaves to stop the spread of the disease. |