Question
My plants have a white powder on them and its killing the leafs.. Plant is still producing new leafs and fruit, but the powder is spreading to the new leafs?? Have tried 7 dust....

Answer
Randall, what you are experiencing is a fungus disease called powdery mildew.  The disease is spread through spores in the soil or air which are splashed onto the plant during rain or blown by the wind.  Many times even indoor plants are affected by plants or soil brought in from outdoors. Although the disease seldom proves fatal, it can cause the plant to prematurely lose its foliage which could result in a smaller harvest.

The best treatment for powdery mildew is lime sulfur. This is an all-purpose fungicide which will help control the disease. Sulfur can be purchased at most garden centers and nurseries.

Another option is fungicidal soap. Gardens Alive, an on-line garden company that specializes in organic products, markets an excellent organic fungicide called Soap Shield. This is a copper-based fungicide that is just as effective as sulfur. The soapy composition of this product causes the fungicide to adhere to the foliage better, resulting in longer protection. You can research this product online at:

http://www.gardensalive.com/product.asp?pn=8066&ss=soap%20shield

I am also attaching a website that will give you detailed information on this disease:

http://www.ag.ohio-state.edu/~ohioline/hyg-fact/3000/3047.html

I hope this information helps.  Good luck, and please write again if I can ever be of assistance.

Regards,

Mike