Potato Y

Potato virus Y (PVY)

[synonym: Brinjal mosaic virus (BMV)]

Symptoms are variable in appearance and severity depending on the variety infected, the isolate of the virus present, age of the plant at the time of infection and environmental conditions. Leaf symptoms include mottling, vein-banding and clearing, and distortion. Plants may be stunted with necrosis of the stems and apical buds. Infected eggplants may show concentric rings on the foliage. Affected fruits may be distorted, discolored and small. Field plants are usually infected by more than one virus. Multiple infections result in symptoms more severe in appearance and more complex than those caused by PVY alone.

Many weed species serve as alternate hosts for this virus. Like Tobacco etch virus, Cucumber mosaic virus and Pepper mottle virus, PVY can be transmitted by many species of aphids. All four viruses are transmitted in a non-persistent manner on the mouth parts of aphids moving into fields from nearby host plants (including peppers, tomatoes, eggplant, tobacco, potatoes and solancaceous weeds). Aphids can cause secondary spread of infection within a crop, or the virus may be transmitted mechanically through staking, pruning or handling infected plants.

Remove crop residues and weeds that can help harbor the virus, and rogue symptomatic plants to help reduce disease spread. Use reflective mulches to deter aphids and stylet oils or insecticides to reduce losses in young plants. Chemical control of the aphid populations is very difficult and provides limited control. In mature plants, it is difficult to achieve complete insecticide coverage of leaves to effectively eradicate all aphids. Resistant varieties are commercially available in both hot and sweet pepper. However, new strains may emerge that overcome existing resistance genes.