Dematophora pepo root rot

The disease is caused by the fungus Dematophora pepo, a soil-borne pathogen that primarily infects the root system and the crown of plants in the Cucurbitaceae family. This pathogen is known for its persistence in the soil, making it a challenging issue for growers who maintain intensive crop rotations.

Key crops susceptible to this fungus include pumpkins, squashes, marrows, and cucumbers. The fungus typically invades the roots through wounds or lesions, systematically colonizing the vascular tissues and effectively cutting off the supply of water and nutrients to the aerial parts of the plant.

Early symptoms appear as stunted growth, leaf chlorosis, and sudden wilting during periods of peak transpiration. A diagnostic check of the root zone often reveals a dense, white mycelial growth, which eventually darkens and produces sclerotia, enabling the fungus to survive adverse environmental conditions.

Environmental triggers for the development of Dematophora pepo include high soil moisture levels and temperatures exceeding 20°C. Poor drainage in field conditions or waterlogged greenhouse substrates create an ideal microclimate for the fungus to spread rapidly and infect healthy plant tissues.

Effective disease management relies on an integrated approach, starting with long-term crop rotation to minimize the accumulation of soil-borne inoculum. Farmers should focus on improving soil drainage, utilizing healthy seeds or transplants, and applying microbial antagonists such as Trichoderma species to suppress the pathogen's activity in the rhizosphere.