Damping off is a common fungal disease that affects the seedlings of chili plants. It is caused by various species of soil-borne fungi that thrive in warm and moist conditions. The disease attacks the stem and roots of the seedlings, causing them to wilt, collapse, and die. Damping off can occur at any stage of plant development, but it is most common in young seedlings.
Chili damping off needs adequate hygiene and culture media. Disease-free seeds, clean growing soil, and proper watering and ventilation will prevent damping. Damping off can be reduced by not overwatering, spacing plants, and fertilizing with nitrogen. Chili damping off can be managed with fungicides and biological control agents. Fungicides can control the disease if used properly. Trichoderma spp. can prevent damping off and promote plant growth.
Damping Off Management in Chilli/Peppers
Cause/Pathogen of Damping Off
Damping off is a fungal disease caused by various soil-borne fungi, including Pythium aphanidermatum, Pythium spp., and Rhizoctonia solani. These fungi thrive in warm, moist soil conditions and attack the stems and roots of seedlings, causing them to wilt, collapse, and die. Stressful conditions such as water-logging or high nitrogen application weaken the plants and favor the disease’s development. The disease can be spread through contaminated tools or equipment and mud on clothes or shoes.
The Disease Cycle of Damping Off in Chilli
Damping off is a fungal disease affecting chili plants during the initial growth stages, especially young seedlings. The disease can survive in the soil as oospores in the case of Pythium or sclerotia in the case of Rhizoctonia. Under favorable conditions, such as irrigation water, the disease can spread through zoospores or mycelial growth in the soil. While the disease may not carry over from one season to another, it can appear suddenly and spread quickly, causing significant losses in crop yield.
Conditions Favorable for Damping Off Spread in the Field
- The disease thrives under specific conditions such as warm and rainy weather, excessively moist soils, and densely sown plants.
- Additionally, stressful conditions like water logging and high nitrogen application can weaken the plants and further promote the spread of the disease.
- Heavy rainfall, excessive irrigation, poorly drained soil, and close plant spacing are favorable conditions for damping off.
- For Rhizoctonia, the fungus responsible for damping off, high soil moisture with temperatures around 30-35°C is ideal for its growth and spread.
- Farmers should be aware of these conditions and take preventive measures to minimize the risk of damping off.
Damage Symptoms of Damping Off
- Reduced seed germination and poor stand of seedlings
- High seedling mortality, ranging from 25-75%
- Pre-emergence damping off, where seedlings disintegrate before they emerge from the soil surface.
- Post-emergence damping off, where the disease develops after seedlings have emerged but before the stems are lignified
- Water-soaked lesion formation at the collar region of the stem
- Infected areas turn brown and rot, leading to the collapse of the plant.
- In Rhizoctonia solani attack, infected stems become hard and thin, resulting in wire stem symptoms, and infected seedlings topple over.
- The disease appears in patches both in nursery and field beds.