White rust

White rust, caused by the oomycete Albugo candida (and related Albugo spp.), is a significant fungal-like disease affecting members of the Brassicaceae family. Crops such as winter rapeseed, turnip, mustard, and cabbage are particularly susceptible, making this pathogen a global concern for oilseed and vegetable production.

The characteristic symptoms of the infection include the formation of white, powdery pustules on the undersides of leaves and on stems. A severe manifestation of the disease is the distortion and hypertrophy of inflorescences, known as "staghead," where flower buds become thickened, twisted, and sterile, preventing pod development.

Environmental conditions play a critical role in the disease cycle, with cool to moderate temperatures (10–20°C) and high humidity or leaf wetness being essential for spore germination and infection. The pathogen can survive for several years in the soil as oospores or within crop residues, enabling carry-over from one season to the next.

The economic impact of white rust is manifested in reduced photosynthetic capacity and disrupted nutrient transport in the plant. This leads to diminished plant vigor, stunted growth, and substantial losses in seed yield and oil content, often necessitating timely intervention to maintain commercial profitability.

Control strategies focus on preventing the buildup of inoculum and protecting the crop. Management practices include long-term crop rotation, the use of certified disease-free seeds, deep plowing to bury infested residues, and the strict control of wild cruciferous weeds. When conditions favor disease development, foliar fungicide applications are essential.

• Selection of resistant cultivars or hybrids.
• Timely removal of infected plant debris from the field.
• Application of protective fungicides during early stages of infection.
• Optimizing planting density to ensure better air circulation and leaf drying.