Neem Seed Extract As a Pesticide

If you’re looking for an organic and earth-friendly way to control insects in your farm or garden, neem seed extract is a very good choice to consider. It contains azadirachtin, the main active ingredient responsible for its pesticidal effects. Neem seeds come from the neem tree, a popular medicinal tree that originate from India. The tree can grow in Africa and in many other continents.

Some people get discouraged when they spray neem seed extract and nothing happen. They expect to see the insects die in masses within a few hours. But neem seed extract doesn’t work like that. It takes about a week to start seeing the effect.

Neem Tree

Neem Tree
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How Does Neem seed extract Pesticide Works?

Neem extract will kill only insects that consume it. It is a hormone disruptor. Neem extract contains a lot of active ingredients that can disrupt the normal functioning of the hormones of insects that eat it. Such insect may stop eating, mating, laying eggs, or flying. It can also prevent eggs from hatching or larvae from molting. Over a period of days, the insects will disappear.

How to Prepare Neem Seed Extract

Neem fruit has an outer pulp covering it. This pulp should be remove since it doesn’t have any insecticidal property. One way to easily get rid of the pulp is by leaving it in a moist area to rot away. Once rotted, you can easily remove it with your hands to reveal the seeds. Drying the seeds and cracking them open will reveal the kernel(s). But note: Use only fruits that have fallen down from the tree as immature green fruits will not give a good result.

ripe and unripe neem seeds

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There are several ways to prepare this extract. One way is to crush 50g neem seeds or 25g neem kernels and soak in 1L of water. Soak overnight in water, stirring as frequently as possible. Filter and mix in 1-2ml liquid soap per liter of the extract. The liquid soap acts as an emulsifier, helping the oil in the seed to mix with water. You may also add molasses at 4ml/L to act as a sticking agent, helping the spray stick to leaf surfaces.

In severe pest situations, you can use as high as 100g neem seed or 50g kernel per liter of water.

How to Use Neem Seed Extract

Seed Treatment: soaking seeds like okra, rice, cucumber, pepper, tomato etc. in neem seed extract can help protect the plant from diseases and pests. For example, mix 63g of crushed neem seeds with 1kg of rice seed and add sufficient quantity of water. Allow them to soak overnight before planting. This treatment will protect the rice against rice gall midge, thrips, brown rice plant hopper, soil-borne insects and crabs.

You can dilute neem seed extract and use it as a soil drench for plants to absorb through the roots. The neem extract will accumulate in tissues deep inside the plant but almost none will be available in the outermost layer of the plant. As a result of this, only insects (like grasshopper and leaf hoppers) that can bite deep enough to access the neem will be affected. Insects like aphids that can’t bite deeply won’t be affected though, so use neem foliar spray against them. Some vegetables like onions, cabbages, and tomoatoes do not like soil drenches with raw neem oil. Spray them instead.

Pests Affected by Neem Seed Extract: It can be used to control the following pests: aphids, leafminers, beet armyworms, mealy bugs, beetles (including flea beetles), nematodes, fungus gnats, grasshoppers, mites, cabbage worms, moth larvae, thrips, caterpillars, japanese beetles, whiteflies and more.


Residue of neem extract on plants is not poisonous to man or animals, unlike most chemical insecticides.

How to Get the Most Out of Neem Seed Extract Pesticide

It is especially susceptible to UV light from the sun, so spray it in the morning or late evening. Spraying during these periods will also help you to avoid suffocating beneficial insects which are usually active in the middle of the day. Also, start spraying this extract on your plant when they’re still young. Doing so will ensure that your plants grow up healthily and build up immunity against pest and diseases. You can spray the extract every 7-10 days. Spray more often during the rainy season.

Precaution: Before you apply any spray on your plants, first test it on few plants and wait for 7 days to see if there is any bad effect. If there is none, you can proceed and spray the rest. But if your plants’ leaves start dying, review your formulation because it may be too concentrated. For example, 10g soap per liter water can kill plants.

Neem Seed Extract and Beneficial Organisms

There are a lot of insects that does not attack crops. Few examples include honey bees, parasitic wasp, lady beetle etc. Neem extract affects only insects that eat plants or suck plant sap and beneficial insects don’t do these – except bees that eat pollen. However, scientists have found out that neem oil will kill bees only at very high concentrations, higher than what you’ll ever use in your garden.

While neem hurts aphids, whiteflies and the like, it does not harm ladybugs and other predators that eat the aphids, or the tiny wasps that are parasites on many pests.

But spraying neem seed extract directly on beneficial insects may suffocate them. Don’t spray the extract directly on flowers bees are visiting. For neem oil, weekly spray at a normal concentration (0.5% – 2%) will not hurt honey bees at all.

What about earthworms? Will neem seed extract harm them? No it wouldn’t.  Earthworms has been known to grow better in the presence of neem seeds or neem leaves.

Neem Seed Extract Against Plant Diseases

Neem seed extract is a powerful antifungal and antiviral agent. It is effective against blackspot (roses), powdery mildew, anthracnose, and rust.

Precaution: As with every other organic spray, test this extract on a small portion of the plants and allow about 2 days to pass. If there is no damage on any leaf, then you can spray the whole plants. Also avoid application to plants that are stressed due to drought or over watering.

If you intend to use this extract to control fungal diseases, make sure the leaves are completely coated – top and under.

Natural pesticides and fungicides like neem are harmless to our health. But they might not be the best when disease pressure is very high. You will get better result if you start using them from seedling stage and when you apply them more frequently. If disease or pests build up despite doing these, switch to chemical fungicides and insecticides to arrest them.

Scientists’ View

Do scientists agree with all these? You may want to check this link out: Azadirachtin from the neem tree Azadirachta indica: its action against insects.

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