Eremothecium gossypii

In its natural environment, the fungus is characterized by rapid mycelial growth, which can penetrate deep into host tissues by utilizing enzymatic systems to break down cellular walls.

Morphologically, the pathogen consists of septate mycelium forming conidia. In laboratory settings, it is often cultivated for the industrial production of riboflavin, but in field conditions, it manifests as an aggressive parasite.

The fungal life cycle involves both sexual and asexual reproduction. Plant debris serves as the primary source of infection, where the pathogen can persist in the form of chlamydospores or dormant mycelium.

The spread of Eremothecium spores is primarily facilitated by insect vectors, which carry the infection from diseased plants to healthy ones, making the fungus extremely difficult to control during epiphytotic years.

The primary host for this pathogen is cotton, where it causes a disease known as "internal boll rot." Additionally, the fungus is capable of infecting tomatoes, soybeans, and several other solanaceous and leguminous crops.

The destructiveness of Eremothecium lies in its disruption of the cotton boll maturation process. The fungus enters through punctures made by insects and develops within the fruit.

The consequence of infection is the total destruction of the fiber, which loses its physical and mechanical properties, becomes brittle, turns a yellowish or brown color, and loses its commercial value.

In addition to direct fiber crop loss, the pathogen reduces seed germination rates, as the mycelium penetrates the seed coat and depletes the nutrient reserves in the embryo.

The economic damage from the spread of this fungus in cotton-growing regions can reach significant scales, leading to losses of up to 30–50% of the harvest in years of high vector population.

The primary sign of cotton infection is a change in the appearance of the bolls: they may wither prematurely or remain underdeveloped while appearing healthy on the exterior.

When the boll is opened, a grayish or yellowish cotton-like mycelial mat is discovered inside, consisting of conidiophores and spores of the parasite that densely wrap around the fiber.

Leaves of infected plants often yellow, which is linked to systemic intoxication by fungal metabolic products that release toxins into the plant's vascular system.

In the case of seed infection, discoloration and a specific odor are noted, indicating the onset of enzymatic decomposition processes within the fruit tissues.

In tomatoes, symptoms manifest as fruit spotting and general plant suppression, accompanied by leaf curling and the subsequent death of generative organs.

The main method of control is the management of insect pests, such as mirid bugs, which are the primary spore vectors and create entry points for the infection.

A critical agronomic element is deep autumn plowing, which facilitates the rapid mineralization of plant residues that serve as infection reservoirs during the winter period.

Crop rotation is recommended, specifically avoiding crops susceptible to Eremothecium gossypii on fields with a high infection history.

The use of systemic chemical fungicides is effective only during the early phases of infection development, though the success of such treatments depends directly on the thoroughness of pest population monitoring.

The breeding of resistant cotton varieties is the most promising long-term direction, aiming to create plants with physical barriers in the boll structure that prevent pathogen penetration.