A very good spray can be made easily from the seeds of the neem tree. It is effective for dealing with many chewing and sucking insect pests in the larva or adult stages of their life cycle. Seeds are dried, crushed into powder, and soaked overnight in water. The spray can then be applied to plants being attacked by a wide range of insects.
Information on this subject area was requested by DCFRN participants in 40 developing countries.
Presenter: George Atkins
Interviewee: G. Venkataramani (“Venkat”), Agricultural Correspondent, The Hindu, Madras, India.
Before using this information, please read the notes at the beginning and end of item 4 of this package about this and related DCFRN items.
Collecting, drying, and storing the seeds
You may be able to find the seeds on the ground under the neem trees, where birds leave them after eating the fruit. If you do collect them, wash off any of the fruit that’s still sticking to the seeds. Otherwise, gather ripe neem fruit, and wash or scrub off the soft, fleshy part. (By the way, that leftover pulp is good for fertilizer. You can add it to the soil in your garden or to your compost pile.)
Now you have your neem seeds, dry them well, otherwise they’ll easily get mouldy and spoil. Spread them to dry in the sun, preferably on mats, and stir them from time to time so they dry evenly. After three or four hours in the sun, you could put them in the shade for a while so they don’t get too hot. Keep drying them this way for several days. Then put them into baskets or woven sacks. Do not put them in plastic bags. Keep them in a dry, airy place until you need them.
Now it’s always good to look carefully at your growing crops as often as you can—every day if possible. You will then know when any insect pests begin damaging your crops. When they do attack, start to prepare the spray right away, the day before you plan to apply it.
Preparing the spray
To prepare the spray, first decide how much you think you’ll need. You should use about one big double handful of neem seed for every litre (quart) of spray you prepare. That’s the amount of neem seeds that you can scoop up when holding both hands together. So for 10 litres (two gallons) of spray, you’d use 10 big double handfuls of seed. For 20 litres (four gallons), you’d use 20 double handfuls, and so on.
After you’ve used neem spray a few times, you’ll learn by experience how much to prepare. So why not try it first with one litre (quart) of clean water and one double handful of dried neem seeds. Be sure that the seeds are clean with no mould or dirt in them. Crush or grind the seeds into a coarse powder; then mix this powder with the water in the proper proportions. Stir the mixture well. Then leave it covered up overnight.
The next day, filter the mixture. You could do this with a fine cloth or several layers of coarser cloth. If you’ll be applying with a sprayer, be sure to filter it very well so it won’t block the spray nozzle. And now you’re ready to apply this no-cost neem seed spray to your crop.
Applying the spray
Whenever using neem seed spray, it’s important to apply it all on that first day after you mixed the dry crushed seeds with the water. Even one day later, it won’t be as good for dealing with the pests that are attacking your crops.
To apply your homemade neem spray, you can use a sprayer, or a watering can; or you could use a small broom or even a bundle of leaves. Here’s how Venkat says farmers do it in southern India.
It doesn’t necessarily kill the pests, but it often stops them from eating your crop, or from laying their eggs. In many cases. the pests may eat some of the treated crop but then they get sick and don’t do any more damage. You’ll find that the neem spray affects different pests in different ways; but in each case, they don’t bother your crops any more.
Just one word of caution. There is a chance that this spray could be harmful to certain kinds of fish. So if you want to go after insects attacking your rice and if you’re raising fish in your paddy field, it would be a good idea to try the spray first in a small area to make sure it doesn’t affect your fish.
Otherwise, neem spray is very safe to use. It doesn’t hurt people or animals, but it is effective against many kinds of insect pests.
Serving Agriculture, the Basic Industry, this is George Atkins.
1. This item is the second of four items on neem in this package. It may either be used alone or in the proper sequence together with the other items as part of a series.
2. For other notes that apply to this and the other three items on neem, see page 4 of item 4 in this Package.
See item 4 in this package.