Ceratorhiza root rot

The fungus Ceratorhiza hydrophila is a significant soil-borne pathogen known for causing root rot and damping-off in various agricultural crops. It thrives in the rhizosphere, utilizing its saprophytic capabilities to survive on dead organic matter before colonizing the root systems of living hosts when favorable conditions occur.

The host range of Ceratorhiza hydrophila includes a diverse array of cereals, vegetables, and ornamental plants. It is particularly damaging during the seedling stage, where the infection can lead to complete stand failure. Older plants may also suffer, showing reduced vigor and limited yield capacity due to damaged root systems.

Symptoms typically begin with a decrease in plant vigor followed by leaf chlorosis and wilting. Upon inspection, the root system often shows signs of necrosis and browning. In cases of high humidity, thin white or greyish mycelium may be visible at the base of the stem. These necrotic lesions eventually disrupt water and nutrient transport, leading to the collapse of the plant.

The development and spread of the disease are strongly linked to high soil moisture levels and moderate temperatures. Factors that exacerbate the infection include poor soil drainage, compaction, and intensive monoculture systems that allow pathogen populations to build up in the soil. High humidity levels at the surface level facilitate the rapid spread of the fungus between adjacent plants.

Effective management and prevention strategies are essential to mitigate the impact of the disease:

• Implementing rigorous crop rotation cycles to break the pathogen's life cycle.
• Ensuring proper soil drainage and aeration to prevent excessive humidity.
• Using high-quality, fungicide-treated seeds to protect against early infection.
• Sanitation practices, including the removal and destruction of infected plant debris.
• Application of systemic fungicides when environmental conditions favor disease outbreaks.