Miyajima

Systematically, this object occupies a place in the fungal kingdom, representing a highly specialized microorganism capable of penetrating the vascular system or tissues of the host plant.

This phytopathogen is characterized by a high degree of adaptability to temperature fluctuations, which allows it to maintain viability in soil or plant debris for several seasons.

Identification of the pathogen in laboratory conditions requires microscopic analysis to detect characteristic sporulating structures and mycelium.

Morphologically, the pathogen may manifest as a specific coating, the color and consistency of which depend on the stage of the organism's life cycle and the overall health of the plant.

Miyajima primarily affects vegetable and ornamental crops, disrupting the normal process of photosynthesis and metabolism within the affected plant tissues.

The main victims of the pathogen are the root system and the root zone, which leads to the blockage of nutrient and water supply to the aerial part.

Affected plants show a sharp decrease in the market quality of fruits, their deformation, and premature shedding, which causes significant economic losses to farmers.

In conditions of high concentration of infectious material in the soil, the development of mass chlorosis, which turns into necrosis of leaf tissues, is possible.

The greatest harm is noted when cultivating susceptible varieties in greenhouse conditions, where the microclimate promotes the rapid spread of infection.

Active development of the pathogen is timed to periods with high humidity and moderately high temperatures, which are optimal for spore germination.

In field conditions, the peak of infection spread usually occurs in the second half of the growing season, when plants are maximally weakened by fruit production.

Initial infection occurs in early spring as soil temperature rises, when dormant forms of the pathogen activate and begin to search for susceptible tissues.

Prolonged rainfall and the lack of adequate soil aeration create an ideal background for the progression of the disease in outbreak areas.

The completion of the development cycle often coincides with the harvest period, when the pathogen enters the form of microsclerotia for successful overwintering in plant detritus.

Visual signs of infection include specific spots that increase in size over time and acquire a distinct dark border.

In the early stages, a barely visible fluffy coating may appear on the underside of leaves or at the base of the stem, indicating the beginning of sporulation.

Wilting of the plant during the day while maintaining turgor at night serves as a sure signal that the pathogen has entered the vascular bundles and is hindering normal sap flow.

• Yellowing of lower leaf tiers.
• Stunted growth and development of shoots.
• Darkening of root tissues.
• Fruit deformation.
• Stem cracking.

As the disease progresses, plant tissues become flaccid and emit a specific unpleasant odor due to secondary bacterial infection.

The main method of control is strict crop rotation, which excludes returning susceptible crops to the infected area for 3–4 years.

Agrotechnical measures should include deep plowing of the soil after harvest to destroy plant residues that act as an infection reservoir.

The use of certified, pathogen-resistant planting material significantly reduces the risks of mass infection over large areas.

The chemical protection method involves the use of systemic fungicides during periods of greatest crop vulnerability, strictly adhering to dosage regulations.

Biological control agents based on the use of antagonistic bacteria show high efficiency for preventive purposes when applied regularly in greenhouses.