By Umar Nsubuga
Early blight Early blight (EB) is a disease of Irish potatoes caused by the fungus Alternariasolani. It is found wherever potatoes are grown.
The disease primarily affects leaves and stems during the early stages of growth, and if left uncontrolled, can result in considerable defoliation and enhance the chance for tuber infection.
Gideon Zakke, an agronomist says it may lead to a considerable reduction in yield. It is characterised by the formation of lesions, withering, and death of parts that occur before plants mature.
Symptoms
Brown circular “burn-like” spots on leaves, and stems lose colour. Young plants may be destroyed before flowering. Dry spots on tubers.
Prevention
- Use clean disease-free seeds. Isaac Malinga, a commercial farmer says mulch gardens to minimise soil splash which spreads fungus.
- Use crop rotation
- Use adequate fertilisers to keep the plants growing strongly (weaker plants are easily affected).
- Remove plant residues immediately after harvesting. Plant resistant varieties.
Treatment
Eradicate weeds, remove and burn the diseased plants. Allow tubers to mature fully before harvesting. Remove and destroy the affected plants by burning or deep burying them.
Zakke says infected tubers are unfit for human consumption, because of the poor tests and also the nutrients are destroyed by the disease.
Leaf blight
Moses Kiptala, an Irish potato farmer says leaf blight is a plant disease that affects stems, leaves, branches and tubers causing pale green to brown patches to form on the leaves.
Symptoms
Rotting of the leaves with brown or black spots, leaves drop, stems become weak and wilting of leaves.
Treatment
- Plant tobacco trees at the corners of the garden and the middle.
- Sprinkle the plants with dry ash. This should be done early in the morning when the dew is still on the plant and/or in the evening.
- Spray the garden with filtered ash mixed with 20 liters of water, 1 kg of red pepper to 5 litres of human urine (stored for one day).
