Sporidiobolales fungi

The order Sporidiobolales belongs to basidiomycetous yeasts, which include both saprotrophic species and dangerous phytopathogens capable of infecting a wide range of agricultural crops. These organisms often inhabit the surface of leaves (phyllosphere) and the soil, forming characteristic colonies with reddish or orange pigments, caused by the accumulation of carotenoids.

The pathogens are microscopic fungi that act as parasites, entering plant tissues through natural openings like stomata or through micro-lesions in the epidermal layers. In agronomy, they are often categorized as agents of various leaf spots, which cause premature senescence of the foliage and a decrease in the photosynthetic activity of the crop canopy.

These pathogens primarily affect cereal crops, including wheat, barley, and maize, as well as some vegetables and forage grasses. Infection manifests as the formation of chlorotic or necrotic spots, which can eventually merge to cover significant areas of the leaf blade. In conditions of high humidity, a faint powdery film representing the fungus's sporulation may be observed on the affected areas.

Disease development is closely tied to climatic factors: optimal conditions for mass spread are moderately warm weather (from +18 to +25 °C) and high air humidity or frequent precipitation. Spores are easily disseminated by wind, rain splashes, and insects, allowing the infection to quickly encompass large fields during the active growth phase of the crop.

The harmfulness of Sporidiobolales lies in significant yield loss and deterioration of crop quality, as premature leaf drying disrupts the grain-filling process. For crop protection, a comprehensive approach is recommended: utilizing resistant cultivars, adhering to crop rotation, and timely application of fungicides upon the first signs of infection. Controlling weeds, which can serve as reservoirs for the pathogen during the off-season, is also critically important.

• Optimizing seeding density to improve air circulation
• Application of triazole and strobilurin-based fungicides
• Removal of crop residues as a source of inoculum
• Monitoring phytosanitary status before the heading stage