How to protect your banana plants, coconuts, and beans from monsoon diseases

With the arrival of the monsoon, the surge in humidity and waterlogging creates a breeding ground for various plant pathogens. If you are growing bananas, coconuts, or climbing yard-long beans, this wet season demands extra vigilance and prompt action to prevent fungal diseases from wiping out your harvest.

Managing Sigatoka leaf spot in banana plants
If you notice small yellow spots on the lower leaves of your three-month-old Nendran banana plants that gradually turn brown or black and cause the foliage to dry up, your crop is likely battling Sigatoka leaf spot. This is a common and highly destructive fungal disease that flourishes in humid, wet conditions. Left unchecked, it severely stunts plant growth and reduces fruit yield.

To manage this outbreak, prune and safely destroy any infected lower leaves outside your farm or garden. Proper spacing is critical to ensure good air circulation and sunlight penetration. It is also wise to avoid overusing nitrogen-based fertilisers and overhead watering, as wet foliage speeds up the spread of the fungus. For chemical control, spray a 1% Bordeaux mixture or systemic fungicides like Propiconazole or Tebuconazole (diluted at 1 ml per litre of water) at intervals of 15 to 20 days. Additionally, run a soil test to ensure your plants are receiving adequate potassium and magnesium, which naturally boost their immunity against such infections.

Green manuring and bud rot prevention in coconut basins
The monsoon season is an excellent time to enrich your coconut palms by sowing green manure crops like cowpea or daincha (Sesbania) in their basins. Sow about 50g of seeds within a 1.5 to 2-metre radius around the base of each palm. After about two and a half to three months, these crops can be slashed and incorporated back into the soil to significantly boost organic matter and nutrients.

However, the heavy rains and waterlogging of the monsoon also raise the risk of bud rot in coconut palms. As a preventive measure, you can place three perforated sachets containing 5g of Mancozeb fungicide around the crown/bud of each palm. When it rains, the water will gradually dissolve and wash the fungicide into the bud, offering continuous protection against fungal decay.

Warding off monsoon diseases in climbing yard-long beans
Climbing yard-long beans are highly susceptible to anthracnose and other fungal diseases during the rainy season. Symptoms usually manifest as black spots on the stems, followed by the yellowing and premature dropping of leaves. To combat this fungal attack, dissolve 20g of Pseudomonas fluorescens in one litre of water and spray the solution thoroughly over both the leaves and stems. This biocontrol agent acts as a natural shield, keeping fungal pathogens at bay.