FACTSHEETS FOR FARMERS
www.plantwise.orgCreated in Zambia, July 2015
Neem extracts against whiteflies in beans
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
Scientific name(s) > Bemisia tabaci
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
Edited by Plantwise
Plantwise is a global initiative led by CABI
ZM049En
Lose Less, Feed More
Young tiny whiteflies can be easily
killed with neem; about 2 mm.
(Photo by C. Hetzel, UPENN)
Ripened neem fruit that fall off the
tree to prepare neem seed
extracts. (Photo by Dinesh Valke,
CC BY NC ND)
