Neem Oil as Pesticide/Fungicide

High Humidity causes growth of Fungi,Virus and bacterial diseases. I know that vertical growing (using T- Frames) will help as the produce will not come in contact with the soil. 
 
Q.  What is the best cultural method to use and possibly the best chemicals to use, in order to contain  the fungal, Viral and bacterial infections and diseases that attack Tomato, Chili Pepper and other Vegetables in the tropics during rainy season. 
 
A.  Without personal experience I must depend on research, but below is what I’ve found from a site that promotes it.  We teach prevention through proper cultural practices (strong healthy seedlings, no weeds, fast growth, keeping plants off the ground by growing vertically, etc).  Neem Oil is not a true fungicide or pesticide, but acts to prevent those problems.  To the extent Neem Oil is also a preventative measure, and safe to use, we can feel good about its use.
 

“As a preventative neem is mainly used when problems are just starting to show. What is does is to coat the leaf surface, which in turn prevents the germination of the fungal spores. Neem is effective against rots, mildews, rusts, scab, leafspot and blights.  It works as a barrier not as a fungicide. It makes a great garden spray as a general tonic for your plants and soil. Earthworm populations have been showed to increase with the use of neem as a tonic.

How  do you use neem oil?

“The product is mixed with water at a ratio of 0.05% to 2.0% depending upon the targeted use. You then apply it as a foliar spray keeping it agitated during application to keep it well mixed. It must be used within 8 hours after mixing with the water. It comes with complete instructions.

How safe is it?

“It is non toxic to humans, birds, earthworms or animals. Being an oil it can affect bees if it is actually sprayed on them so it is recommended to use it when bees are not visiting. Once the spray has settled it will not hurt the bees.

“Visit the Neem Association web site to learn about all the amazing properties of neem oil.