Mulberry fusariosis

The fungus invades the host plant through roots or bark wounds, systematically colonizing the xylem tissue and obstructing the flow of water and essential nutrients.

As the fungus proliferates, it secretes mycotoxins that damage plant cells, leading to a breakdown of physiological processes and eventual tissue necrosis.

The pathogen is highly persistent, capable of surviving in soil or dormant plant debris for several years even without a susceptible host plant present.

Dissemination occurs via airborne spores and movement through contaminated water, soil particles, or tools used during pruning and harvesting operations.

Initial symptoms typically manifest as sudden wilting of leaves and young shoots, often starting in isolated branches before spreading throughout the canopy.

Cross-sections of affected branches reveal characteristic brown or black vascular discoloration, which serves as a definitive diagnostic feature of the disease.

As the infection advances, the bark may exhibit deep cracks or sunken necrotic ulcers, sometimes accompanied by white or pinkish mycelial growth in humid conditions.

Foliage on infected branches yellows rapidly, curls, and falls off prematurely, leaving behind bare twigs that gradually lose their viability.

In chronic cases, the entire tree displays severely stunted growth, reduced fruit production, and eventually dies if the root system becomes fully compromised.

The development of the fungus is strictly dependent on high soil moisture levels and warm temperatures, which facilitate the rapid germination of resting spores.

Inadequate drainage and heavy soil compaction significantly increase the risk of root infection by enabling the fungal mycelium to travel through the rhizosphere.

Trees stressed by drought, extreme temperature fluctuations, or pest infestations are more susceptible to the initial invasion by Fusarium mori.

Poor sanitation practices in the orchard, such as leaving debris under trees, create reservoirs for the pathogen to thrive and re-infect the orchard annually.

Pruning during wet weather or using unsterilized tools provides the fungus with direct entry points into the vascular system of otherwise healthy trees.

Fusariosis represents a major threat to commercial mulberry production, as it can kill mature trees and lead to total loss of orchard productivity over time.

Reduced foliage production significantly impacts sericulture operations, as the health and yield of silkworms depend on the quality of mulberry leaves.

The disease compromises the structural integrity of the tree, making it prone to wind breakage and secondary decay by opportunistic saprophytic organisms.

Once established in the soil, the pathogen is extremely difficult to eradicate, often necessitating the abandonment of infected land for several years.

Economic losses arise not only from reduced output but also from the high costs associated with rigorous monitoring, tree removal, and soil remediation.

Prevention relies on selecting disease-resistant cultivars and ensuring that trees are planted in well-drained soil with adequate space to improve air circulation.

Strict orchard sanitation is mandatory; all infected branches and debris must be pruned, removed from the site, and destroyed by burning to minimize inoculum levels.

Sterilizing pruning tools with alcohol or appropriate disinfectant solutions between every single tree is critical to preventing the spread of the fungal spores.

Applying systemic fungicides can help suppress the disease if detected in the early stages, though this should be combined with robust cultural management practices.

• Regular application of potassium-based fertilizers to improve tree vigor
• Proper soil management to prevent waterlogging around the root zone
• Monitoring for insect damage to reduce entry points for the pathogen
• Removing and destroying severely infected trees including roots