Explore effective methods and important practices for controlling onion diseases in horticultural settings. Learn how to manage common threats like fungal pathogens and minimize losses in your onion crops.
Which common fungal disease often creates white, fluffy growth at the base of onion plants, especially in damp conditions?
Explanation: White rot is characterized by white, cottony fungal growth at the onion base and thrives in wet conditions. Bacterial blight mainly affects leaves and lacks the white fluff. Downy mildew causes purple-gray patches on leaves, not at the base. Pink root causes pinkish roots without fluffy structures.
Why is rotating onion crops with unrelated plants recommended for disease control?
Explanation: Rotating crops helps break disease cycles by depriving pathogens of their preferred host. It does not inherently change soil acidity, directly affect sunlight exposure, or eliminate weeds by itself.
What is the optimal time to apply fungicides for controlling downy mildew in onions?
Explanation: Preventative fungicide applications reduce the risk of infection before it starts. Applying after harvest or at bulb maturity is ineffective for control. Application during midday may reduce effectiveness due to evaporation or plant stress.
How does removing infected plant debris help control onion diseases?
Explanation: Clearing debris removes disease reservoirs that could infect future crops. This practice does not directly influence flavor, bulb size, or soil fertility, but aims to reduce disease pressure.
Why might a grower choose disease-resistant onion varieties?
Explanation: Resistant varieties can help limit disease impacts, providing an important management tool. They do not substitute for weed control, ensure larger bulbs, or remove the need for proper watering.