Maize smut infection causes the corn kernels to swell up into tumor-like galls (Pic: Courtesy)
Smut is a maize disease that is caused by the pathogenic fungus Ustillago maydis. The fungus forms galls on maize cobs and is most vigorous in warm weather. The early signs of an attack are whitish galls that later rupture to release dark spores capable of infecting other corn plants.
To prevent this disease, farmers should plough their farms deep to bury surviving spores that were overwintered in the previous year. Crop rotation with non-cereal plants such as cassava and sweet potatoes should be practiced. Clean and disease-free maize seeds should be used in planting because the disease is also seed borne.
Chemical control is not very effective. Seed dressing is the most effective management option with the following: Carboxin 15%+Thiram 13% (e.g Vitaflo 280) 1.5g per kg seed should be applied.
Farmers are advised to Plant resistant/ tolerant varieties e.g., WH699 at the onset of the rains for good crop establishment. Do not use higher rates of manure and nitrogen because disease incidence is higher in soils that contain a lot of nitrogen. Avoid injuring roots, stems and leaves during weeding as this creates entry point for the disease. It is also good to eliminate volunteer host plants such as sorghum and finger millet.
READ ALSO: Farmer turns to short season maize to escape lethal necrosis disease
READ ALSO: Farmer boosts maize nutrition with soy beans
READ ALSO: Farmer intercrops maize with vetch to boost milk production
When plant reaches knee height, check weekly for the presence of whitish grey tumor- like galls/ swelling on tassels, husks, ears/kernels, stalks, leaves, prop roots and take action as soon as one infected plant is observed by cutting out and destroying the gall before the smut ruptures . Destroy the infected plants by burning or burying away from the maize farm.
In case the affected plants are destroyed, avoid feeding livestock with infected materials because the spores can be transmitted through manure.