Phomopsis leaf spot has become increasingly important in South Carolina in recent years. The disease starts to develop in the fall or spring shortly after planting. It spreads rapidly and can kill much of the foliage. It remains active as long as there is green foliage on the plants. If plants become dormant in the winter, the disease will start again in the spring.
Early symptoms are one-six circular, red to purple spots on leaflets.
Spots enlarge and develop grey centers. Older spots along veins develop into large V-shaped lesions. Fruit and calyx infection also occurs. The fungus survives in dead leaves attached to the plants. Fungicides should be applied when new growth starts and continued in the spring where the disease is a problem.