Marasmius sarmentosus

The disease is classified as a necrosis or root rot. The fungus effectively penetrates the host tissue, utilizing an enzymatic system to break down structural components such as cellulose.

The life cycle involves the proliferation of mycelium, which invades the soil and plant tissue, and the production of small basidiocarps (mushrooms) that release spores.

This fungus acts as a facultative parasite, meaning it can survive for long periods in the soil on decaying organic matter, making it a persistent threat to crops.

Scientific studies indicate that Marasmius sarmentosus thrives in tropical ecosystems, where it contributes to the decay of plant roots in stagnant water environments.

The initial signs include stunting and yellowing (chlorosis) of the foliage, resulting from the inability of the damaged root system to transport nutrients.

A diagnostic sign is the appearance of white, fan-shaped mycelial threads surrounding the root collar and lower stem of the affected plant.

Tissues in the affected area often become soft, discolored, and necrotic, eventually emitting a distinct smell due to the secondary decomposition of plant material.

Plants often exhibit wilting during periods of intense sunlight, even if soil moisture levels appear sufficient, signaling a failure in water uptake.

In high humidity, small mushrooms may appear at the base of the plant, serving as the primary sign of the fungus's reproductive phase.

Development is heavily dependent on high relative humidity, often exceeding 80%, which is necessary for mycelial spread and spore germination.

Optimal temperatures for the growth of Marasmius sarmentosus typically range between +22°C and +28°C, mirroring the climate of its natural tropical habitat.

Poor soil drainage and waterlogging create the ideal anaerobic or semi-anaerobic conditions that favor the fungus over the healthy root tissue.

Overcrowded plantings reduce air circulation, maintaining a microclimate around the base of the plants that promotes infection and rapid spreading.

High levels of plant debris in the soil provide an abundant energy source for the fungus, allowing it to maintain a high inoculum density in the growing medium.

The disease causes significant economic loss by reducing plant vigor, stunting growth, and ultimately leading to the death of the crop.

Root system destruction makes the plant highly susceptible to environmental stress and prevents the efficient use of fertilizers, causing yield decline.

Secondary infections by soil-borne bacteria often follow the initial fungal colonization, complicating the damage and accelerating the death of the plant.

The rapid spread of spores via rain splash or wind can affect vast areas of a plantation, leading to large-scale crop failure within a single season.

Persistence of the fungus in the soil renders the site difficult for the cultivation of susceptible species for several seasons without intensive intervention.

Effective management begins with soil solarization or chemical soil treatment to reduce the initial spore count in fields with a history of the infection.

Improving soil aeration through drainage and balanced fertilization helps maintain plant vigor, allowing the crop to better withstand potential attacks.

Sanitation practices, such as the complete removal and destruction of infected plant debris, are critical to limiting the source of inoculum.

Systemic fungicides may be employed in high-risk environments to protect the root zone during the most vulnerable growth stages of the plant.

• Regular inspection of the plant base for mycelial growth.
• Implementing wide spacing to improve canopy aeration.
• Rotating with non-host species to break the disease cycle.