Fusarium foot rot

The fungus Fusarium pseudograminearum is the primary causal agent of Fusarium crown and foot rot in various cereal crops. This soil-borne pathogen survives as mycelium or spores within crop residues and the soil, making it a persistent threat in many cereal-growing regions worldwide.

The disease affects a wide range of monocots, with wheat, barley, and triticale being the most susceptible. The fungus infects the roots and sub-crown internodes, gradually spreading into the crown and the base of the stems, disrupting the vascular system and water transport of the plant.

Infected plants typically display brown to dark brown lesions at the base of the stems. Under moist conditions, the characteristic pink-to-orange fungal mycelium can be seen at the stem base. Advanced stages of the disease manifest as premature ripening and the development of "whiteheads," which remain empty or contain only shriveled grains.

The development of the disease is highly favored by warm, dry conditions followed by moist periods, as well as by high soil temperatures. The pathogen spreads primarily through the movement of contaminated soil, infected crop debris, and to a lesser extent, through infected seeds, ensuring its survival from one harvest to the next.

The economic impact of Fusarium pseudograminearum is significant, often resulting in severe yield losses and reduced grain quality. Beyond the loss of biomass, the presence of mycotoxins produced by the fungus, such as deoxynivalenol (DON), poses serious food safety concerns, rendering the grain unsuitable for human and animal consumption.

Effective management strategies include:

• Rotating susceptible crops with non-host crops to reduce soil inoculum levels.
• Planting certified, fungicide-treated seeds to protect against early-season infection.
• Managing crop residues to facilitate decomposition and reduce the pathogen's survival site.
• Optimizing fertilizer and water management to minimize plant stress.
• Monitoring for symptoms and applying effective foliar fungicides if conditions warrant.