FACTSHEETS FOR FARMERS
www.plantwise.orgCreated in Zambia, July 2015
Garlic formulations to control aphids in cabbage
Recognize the problem
Cabbage suffers from aphid attacks. Aphids are tiny, pale grey or green, soft-
bodied insects. They can have wings or no wings. They often sit in groups on
the underside of leaves. They suck plant sap, spread viruses and excrete a
sticky liquid that coats the plant. Fungi will thrive on the sticky liquid and
produce sooty mould. Sucking of plant sap causes curling, wrinkling or cupping
of the infested leaves. Plants will be deformed and stunted and produce
unmarketable heads and leaves. Yellowish-greenish mosaic symptoms are due
to virus diseases spread by aphids such as cauliflower mosaic virus and turnip
mosaic virus.
Background
Aphids are often crowded (in colonies) on stems or on the underside of leaves.
An adult aphid can produce up to 20 offspring per day. Under favourable
conditions, aphid populations grow very quick. There are a number of different
plants that aphids do not like. These plants contain substances that are like
insecticides or repellents. Garlic is one of such plants. Garlic extracts can be
used to repel aphids from feeding on cabbage. It can even kill aphids and other
soft insects such as small caterpillars. When 5 to 10 plants of a ¼ acre field
have several leaves with small aphid colonies, then consider spray. However, if
cabbage viruses are known to be in the area, then act earlier.
Management
• Finely chop 10 garlic cloves
• Add 5 to 6 plastic-bottle lids, or about 4 to 5 tablespoons, of mineral oil
or liquid paraffin
• Add 1 litre, or about 4 cups, warm water.
• Mix garlic and oil together and let it steep for 2 days.
• Dissolve 15 grams grated soap (chopped bar soap) or flakes in warm
water and then mix the 2 solutions together. Or add 1 to 2 bottle-lids of
pure, or 1 to 2 table spoons of liquid, soap
• Add 1 part of mixture to 5 parts water (for example 5 cup mixture to 25
cups of water). Put into sprayer.
• Spray directly on the cabbage leaves and heads targeting the pest.
• Sprays must cover the aphids, otherwise they will not work
• Spray in the morning or late afternoons to prevent quick breakdown of
spray by sun, and increase efficiency of the spray.
• Results will show about a day after spraying.
• Repeat the spray after 1 or 2 weeks if needed, but do not spray more
than 2 times a season
• Do not spray 2 weeks or less before harvest
Scientific name(s) > Myzus persicae, Aphis gossypii, Brevicoryne brassicae
The recommendations in this factsheet are relevant to: Zambia
Authors: Sichilima Isaac
Seed Control and Certification Institute (SCCI)
tel: +260977692307 email: isichilima@yahoo.com
Edited by Plantwise
Plantwise is a global initiative led by CABI
ZM047En
Lose Less, Feed More
Cabbage leaf infected with aphids.
(Photo by A. M. Verala, icipe)
Adult wingless aphid that is only 2
to 3 mm long but some have
wings. (Photo by Volkov S.M. et al.,
1955, via Agro atlas)