Mortierella root rot

Mortierella root rot is a plant disease caused by fungi belonging to the order Mortierellales. While many of these fungi are common soil saprotrophs, certain species can become opportunistic pathogens, attacking the root systems of crops, particularly in greenhouse environments or nursery settings where moisture levels are consistently high.

The causal agents are soil-borne zygomycetes that thrive in organic-rich, moist substrates. These fungi act as facultative parasites, exploiting weak or stressed plants to invade the root tissues. By colonizing the roots, they disrupt nutrient and water uptake, leading to systemic decline of the affected plant.

This disease primarily affects vegetable seedlings, ornamental flowers, and various container-grown plants. The infection cycle is often initiated by contaminated soil, peat moss, or water sources. Poor drainage and lack of oxygen in the root zone are critical factors that accelerate the development and spread of the pathogen.

Symptoms of Mortierella infection include stunted growth, chlorosis, and sudden wilting of the foliage. Examination of the root system often reveals necrotic lesions, browning of the roots, and the presence of fine, white, or gray fungal mycelium on the surface of the roots or in the surrounding substrate.

To effectively manage and prevent Mortierella root rot, growers must prioritize soil hygiene and environmental control. Essential strategies include heat-sterilizing growing media, avoiding overwatering, and ensuring optimal soil aeration. Incorporating biological control agents and using targeted fungicides can also mitigate the impact of the disease if infestations are detected early.