Plantwise Factsheets for Farmers
Protect African eggplant from anthracnose
Colletotrichum spp., Glomerella spp.
Recognize the problem
Anthracnose is a fungal disease. It causes grey, dark, sunken lesions on leaves, stems, flowers, and
fruits. On leaves, anthracnose appears first as small, irregular yellow or
brown flat longish spots along veins. Spots darken with age and expand. On fruits,
it produces large grey-dark, sunken spots. In moist weather, pinkish spore masses form in the centre of these spots.
The fruits will rot.
The fungus survives from
year to year in the soil, on crop residues, seeds and weeds. It disperses by water splashes, insects or other
contacts. It can spread quickly during the rainy
seasons. Contact chemicals such as
Mancozeb can prevent such spread and new infections. Mancozeb is a preventative/protectant
fungicide but cannot cure infected plants. It has a
multi site mode of action, meaning that disease resistance to the chemical is unlikely. Mancozeb
is less poisonous (WHO toxicity class U) than many other chemicals. Consider taking action when 3 to 5 plants
per ½ acre have at least one young fruit showing early symptoms. When many
plants have symptoms, then they are nearly all infected, and chemical sprays
will not help any more.
products from a registered agro-dealer
- Mancozeb has many
different trade names such as Dithane, Uthane M45, Rolim 700WP, Manzeb,
Manzane and others.
- Do not buy Mancozeb-Metalaxyl
mixed products. Metalaxyl does not work well against this fungus.
- Usually mix 40g
product with 20 litres, which translates to 200g product per 100 litres or
2-3 kg per hectare. But read product label for dosage
instructions because products differ.
2 tablespoons of sticker (teepol/any liquid soap) per 20 litres of water to
allow the mixture to stick on the leaves. Mix properly.
mid-morning when there is no dew or late afternoons when no wind. Spray whole
plants to achieve good coverage. Do not spray drought-stressed plants.
not enter the field the same day you sprayed.
interval two weeks.
- Do not store left over spray solution, as it
loses power. Dilute any remaining solution in knapsacks sprayer by factor 10,
and spray again onto field to get rid of it.
The recommendations in this factsheet are relevant to:
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