Õlivahtud

Õlivahtud, also known as celtsodomas or oval blotch, is a disease of apricot trees caused by the fungus Mycosphaerella oivahtuditerricola. The disease is characterized by the appearance of oval-shaped necrotic lesions on the leaves of infected plants.

Symptoms of Õlivahtud include the development of raised, sunken, or simply necrotic patches on the upper surface of leaves, often accompanied by a pinkish-colored powdery spore mass on the underside. Infected leaves may also become stunted, curled, or distorted. The disease can lead to significant reduction in leaf area and photosynthetic capacity, resulting in yield losses and reduced tree vigor.

The fungus that causes Õlivahtud is thought to overwinter on infected plant debris and hatch in the spring to infect new leaves. Disease spread is facilitated by rainwater splash, wind, and insects that move between plants. Õlivahtud is typically more severe in wet and humid climates and can be exacerbated by cultural management practices such as pruning and irrigation.

Management of Õlivahtud involves a combination of sanitation, pruning, and fungicide application. Removing and disposing of infected plant material and pruning infected areas of the tree can help reduce disease spread. Fungicides that are effective against Mycosphaerella species may also be used as a preventative measure.

The disease has been reported in various regions, including the former Soviet Union and Eastern Europe, where it is considered an important constraint on apricot production. Monitoring for symptoms and early detection can help prevent the spread of Õlivahtud and reduce its impact on orchard productivity.