Melon root rot is a common and severely damaging disease affecting melons, primarily targeting the roots and basal stem, leading to plant wilting and death, and significantly reducing yield and quality. The disease is primarily spread through soil-borne thick-walled spores, hyphae, or sclerotia, entering through root wounds. Effective prevention requires timely crop rotation, proper fertilization,
1. Common Damages of Melon Root Rot
Melon root rot can cause severe damage after infection. If not managed properly, it can lead to large areas of dead plants. Infected melons show water-soaked lesions at the root and stem base, which later develop into brown spots that gradually expand. The main root near the soil becomes sunken and rotten, leading to wilting of the above-ground parts and no new root growth underground.
When the melon plants wilt and die, examining the roots will reveal that the root system of the diseased plants is yellow-brown and necrotic. Melon root rot primarily affects the roots and root crown. In high humidity conditions, white mold can form on the surface of the root crown, and the vascular bundles at the rotten part turn brown. As the disease progresses, the affected part slightly shrinks and thins, leaving only filamentous vascular tissues.
2. Causes of Melon Root Rot
Melon root rot and quality of melons. But how does melon root rot infect the plants? The pathogens of root rot typically overwinter in the soil and plant debris as thick-walled spores, hyphae, or sclerotia. Thick-walled spores are the primary source of infection. The pathogens often enter the plant through wounds on the roots.
After the melon plants become infected, conidia (asexual spores) are produced at the infected sites, spreading through irrigation water and causing repeated infections. The disease is more likely to occur in environments with high temperature and humidity, low soil temperature, continuous cropping, low-lying areas, and heavy clay soils. The use of incompletely decomposed fertilizers can also cause root burn, leading to disease.
3. Prevention and Control of Melon Root Rot
To control melon root rot, farmers need to respond promptly, especially in greenhouses with severe root rot issues. For greenhouses that have been growing melons for over five years, farmers can practice crop rotation with non-cucurbit vegetables from the Cruciferae or Liliaceae families for more than three years.
When applying fertilizer to melons, it is important to use well-decomposed basal fertilizers and prepare the soil meticulously. High bed cultivation should be adopted, avoiding flooding irrigation. Instead, farmers can use drip irrigation to prevent waterlogging in the fields. Additionally, they should control soil pests, loosen the soil in a timely manner, and enhance soil aeration.