Management Other than buying disease-free plants, destroying wild plants near the planting, and removing diseased plants, controls do not exist. As with most virus diseases, the best controls are preventing disease introduction and detecting the disease when it is still localized in a small portion of the field. Other cultivars may possess field resistance to the disease. This disease was originally thought to be caused by a virus, but is now known to be caused by a mycoplasma-like organism. The only known carrier is the sharp-nosed leafhopper, though other vectors probably exist.
Symptoms vary with the stage of growth, time of year, age of infection and the variety.
Affected plants are dwarfed with shortened internodes, excessively branched, low in vigor with small downward cupped leaves which turn yellow along the margins and between the lateral veins giving a green and yellow mottled appearance. These mottled areas will turn brilliant red prematurely in late summer, although the midrib remains a dark bluish-green. Fruits on affected bushes are small, hard, lack flavor, ripen late if at all, and remain attached to the plant much longer than on healthy plants. Management Planting virus-indexed plants is most helpful. Diseased bushes cannot be cured.