Application: This compound is found in the seeds (0.2 to 0.8 percent by weight) of the neem tree, Azadirachta indica (hence the prefix aza does not imply an aza compound, but refers to the scientific species name). Many more compounds, related to azadirachtin, are present in the seeds as well as in the leaves and the bark of the neem tree which also show strong biological activities among various pest insects  Effects of these preparations on beneficial arthropods are generally considered to be minimal. Some laboratory and field studies have found neem extracts to be compatible with biological control. Because pure neem oil contains other insecticidal and fungicidal compounds in addition to azadirachtin, it is generally mixed at a rate of 1 ounce per gallon (7.8 ml/l) of water when used as a pesticide. Azadirachtin is an extract of fruit from the Neem tree, which is largely grown in India. It is used as a commercial insect growth regulator that controls the metamorphosis process as the insect passes from the larva stage to the pupa stage.
It can be used to control many important pests that are difficult to control on vegetables, such as greenhouse whitefly, diamondback moth, aphids, spider mites, etc. In addition to its inhibitory effect on pests and mites, neem extract also has inhibitory effects on plant pathogens and nematodes. Neem preparations are used to prevent leaf spot, downy mildew, powdery mildew and other diseases of fruit trees and crops.