Plantwise Factsheets for Farmers
Garlic formulations to control aphids in cabbage
Aphis gossypii, Brevicoryne brassicae, Myzus persicae
Recognize the problem
suffers from aphid attacks. Aphids are tiny, pale grey or green,
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.
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.
Finely chop 10 garlic
- Add 5 to
6 plastic-bottle lids, or about 4 to 5 tablespoons, of mineral oil or liquid
- Add 1
litre, or about 4 cups, warm water.
garlic and oil together and let it steep for 2 days.
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.
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.
will show about a day after spraying.
the spray after 1 or 2 weeks if needed, but do not spray more than 2 times a
- Do not spray 2 weeks or less before harvest
The recommendations in this factsheet are relevant to:
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