Anthracnose of blackcurrant

Anthracnose of blackcurrant is a significant fungal disease caused by the pathogen Drepanopeziza ribis. This infection primarily attacks the foliage of currant bushes, leading to premature defoliation and a substantial reduction in the plant's photosynthetic capacity.

The disease affects various species of the Ribes genus, including black, red, and white currants, as well as gooseberries. It is most prevalent in humid climates and densely planted areas where stagnant air and high moisture levels provide a favorable environment for the fungus to thrive.

The initial signs of infection are small, light-brown spots that appear on the leaves. As the disease progresses, these spots darken and coalesce, causing the leaf tissue to wither. Severe infections lead to early leaf drop, which weakens the plant, limits new growth, and adversely affects the yield of subsequent seasons.

The fungal spores overwinter on fallen infected leaves. During the spring, moisture triggers the release of these spores, which are spread by rain splash and wind to healthy foliage. Warm and humid conditions throughout the growing season further accelerate the spread of the pathogen, necessitating constant monitoring.

Effective management requires a combination of sanitation and chemical control. Growers should remove and burn all leaf debris in autumn to reduce the source of inoculum. Improving airflow through proper pruning and applying recommended fungicides at key growth stages are essential steps to keep the bushes healthy.

In addition to fungicide applications, balanced nutrition plays a vital role. Plants that are well-nourished, particularly with potassium and phosphorus, show higher resistance to Drepanopeziza ribis, allowing for better recovery and sustained productivity despite environmental pressures.