Acrophialophora wilt

Early symptoms include the yellowing of lower leaves, which eventually progresses upward throughout the entire foliage of the affected plant.

A hallmark sign of the infection is the loss of turgor pressure; plants appear wilted during the hottest parts of the day, even if the soil is adequately moist.

Cross-sectioning the stem reveals distinct browning or necrosis of the vascular bundles, indicating that the transport system of the plant has been compromised.

Root systems often show signs of decay and necrosis, with reduced development of lateral roots, which severely restricts the plant's ability to uptake resources.

In advanced stages, the plant undergoes total wilting, leading to rapid desiccation and premature death before the pod filling stage is complete.

The disease is caused by the soil-borne fungus Acrophialophora fusispora (often known as Acrophialophora nainiana), which is recognized as a thermotolerant pathogen.

This fungus exhibits strong saprophytic capabilities, allowing it to survive for extended periods in the soil on decaying organic matter and plant residues.

The pathogen functions as a vascular wilt agent, colonizing the plant's xylem and disrupting the normal flow of water and nutrients from the roots to the shoots.

Unlike many other soil fungi, Acrophialophora fusispora is highly adapted to high-temperature environments, making it a persistent threat in arid regions.

Chickpea is the primary host crop where this pathogen causes significant damage, leading to symptoms characteristic of systemic vascular infection.

The development of Acrophialophora fusispora is heavily favored by elevated soil temperatures, typically ranging from 25°C to 35°C, common in summer climates.

Low soil moisture combined with heat stress weakens the host plants, facilitating the colonization of root tissues by the fungal hyphae.

Intensive cropping systems that fail to rotate legumes often see a buildup of the pathogen inoculum in the soil over consecutive seasons.

Seed-borne transmission remains a critical factor, as fungal spores can survive on the surface of seeds, introducing the disease to new agricultural areas.

Poor soil aeration and compaction create an environment that encourages root distress and limits the effectiveness of the plant's natural defense mechanisms.

This wilt disease poses a severe threat to chickpea productivity, frequently causing widespread stand depletion and significant yield losses in affected fields.

The disruption of water transport leads to stunted pod development and poor seed quality, significantly reducing the market value of the harvest.

Fields infested with this pathogen become high-risk zones, requiring careful management to prevent the spread of the fungus to neighboring plots.

In severe epidemic years, growers may face losses exceeding 40% of the total potential yield, which can undermine the economic viability of legume cultivation.

The persistent nature of the fungus in soil makes it difficult to eradicate, necessitating long-term management strategies for soil health.

Effective management begins with strict crop rotation practices, ensuring that susceptible legumes are excluded from the field for at least 4–5 years.

The utilization of resistant or tolerant chickpea cultivars is the most sustainable approach to minimizing the impact of Acrophialophora wilt.

Seed treatments with broad-spectrum systemic fungicides are essential to protect the germinating seeds and seedlings from early-stage soil-borne infections.

Cultural practices such as deep tillage to incorporate crop residues and improve soil structure can help reduce the longevity of the inoculum.

• Balanced NPK fertilization to improve crop vigor.
• Monitoring soil temperatures and humidity levels.
• Use of certified, disease-free seed stock.