Cookies on Plantwise Knowledge Bank

Like most websites we use cookies. This is to ensure that we give you the best experience possible.

 

Continuing to use www.plantwise.org/KnowledgeBank means you agree to our use of cookies. If you would like to, you can learn more about the cookies we use.

Plantwise Knowledge Bank

Your search results

Plantwise Factsheets for Farmers

Neem extracts against whiteflies in beans

Bemisia tabaci
Zambia

Recognize the problem

Whiteflies are tiny white winged insects of about 2mm. They usually sit on the underside of leaves. They fly off when you shake the beans.  Young whiteflies are also white and sit underneath leaves, but do not move much. Young and adult flies feed plant sap which causes yellow spots on bean leaves, and weakens the plants. They release a sugary liquid which covers the leaves when there are many flies. A grey-dark mould then grows on top.

Background

Whiteflies are mainly found in warm weather. Bean plants usually tolerate a few whiteflies per leaf but if there are many, then often chemicals are sprayed which are toxic to you and the environment. Insects do not like some wild plants, like the neem tree. Neem trees can be used to prepare homemade or even commercial insecticides. Leaves can be used but the anti-insect ingredient is most concentrated in the seeds. Neem is an insecticide, insect repellent and anti-feedant. It is used against a wide range of pests such as mites, cutworms, jassids, grasshoppers and also whiteflies.
Neem is a fast growing tree which is wide spread in Zambia. It grows well on poor soils and shallow or stony ground, and requires little rainfall. Neem seeds or neem products can also be bought in agro-input dealer shops. The tree bears fruit when about 4-5years old.

Management

  • Collect ripe golden neem fruits from the tree.
  • The level of anti-insect substances is higher in ripe fruits compared to young fruit
  • Remove the flesh around the seeds and dry the seeds in the sun to avoid rotting
  • Use about ½ a handful of dry neem seed (25 to 50g).  Shell and finely grate or grind.
  • Wrap powder into a piece of cloth and place it in 1 litre (about 4 cups) of water to soak overnight.
  • For a 16 litre knapsack sprayer you would need 6 to 8 handfuls of ground neem seed (800g) to soak in 16 litres of water.
  • Add 1 tablespoon (10mls) of liquid soap or chopped bar soap into 1 litre of spray solution, or about ½ a cup (120 to 150 mls) into 16 litres of spray solution.
  • The soap spreads the sprayed solutions over plants and insects.
  • Spray early morning or late evening when the flies are inactive.
  • Avoid using neem too often as they can destroy useful predators and can be phytotoxic to the crop

The recommendations in this factsheet are relevant to: Zambia

Authors: Expand Fridah K. Chipambala
Plant doctor, Ministry of Agriculture and Livestock
tel: +260978135251 email: chipambala@gmail.com
©CAB International. Published under a CC-BY-SA 4.0 licence.

Plantwise Factsheets Library app

Get all of the factsheets and pest management decision guides from this website in an offline format via the Plantwise Factsheets Library app.