Onions grow under different conditions. They get sick in warm humid climate. Diseases are spread by soil, seed or infected residues.
The symptoms of diseases in onions are brown oval spots, yellow streaks and folding of leaves. To grow healthy plants use improved seed varieties by seeking advice from consultants. Buy treated seed from trusted dealers to avoid low quality seedlings.
Disease prevention
Add compost to the seedbed to maintain healthy and disease resistant onions. Sow seed in a line with proper spacing for air circulation. Remove diseased and weak seedlings when transplanting to prevent the spread of disease. Increase beds at seeding for easier water drainage. Give enough water, but avoid flooding. Always water the plants in the morning to allow them to dry slightly. Regularly weed the plants for good air circulation.
Constant field observation is important to easily identify diseased plants. Uproot diseased bulbs and bury them to control spread.
Apply foliar fertilizers for healthy and hardy plants. Use a variety of fungicides to prevent disease resistance.
Do crop rotation to break the disease life cycle. Do not grow onions in a diseased field for 3 years. Remove plant debris after harvest to prevent reinfection.
