Sudanese Experience with Neem to Control Pests

The following are abstracted from an article in the magazine Baobab, #5, 1990. They in turn learned it from "The Farming World" of BBC World Service.

First a review. You have read in previous issues of EDN and probably elsewhere about this tree's use in insect control. There are many active ingredients, but azadirachtin is perhaps most important. It is found in both leaves and seeds.

For the past 20 years, Professor Ahmed Sadiq has been working with the use of neem in pest control. Recently CARE started trials in collaboration with him. The seeds have about twice the potency of leaves, but seeds are only available for 3-4 months each year. So they are working with leaves.

Leaves are dried in the shade, because the ultra-violet from the sun will break down the active ingredient. When the leaves are dry, they are crushed to a powder in a mortar and pestle. They can then be used directly for dusting crops or as a powder in stored foods. The powder can also be mixed with water and sprayed on crops.

Most farmers like to see pests drop dead right away. Neem does not have this sort of effect, with a few exceptions. Its main effect is as a repellent. If insects do eat the treated plant, the neem has a hormonal and growth-regulator effect. Local farmers have used it only one year. Those who treated okra with it said grasshoppers avoided treated plants.

Farmers who treated watermelon seeds with neem powder said that rats that normally eat the seeds did not eat the treated seeds. Neem is not usually thought of for rodent control, but it has a flavor which perhaps the rats did not like.