Symptoms and Signs
Asparagus viruses I and II produce no distinct symptoms unless both viruses infect the plant. Either virus by itself may only slightly reduce vigor. When both are present in the same plant, survival and vigor are severely reduced, especially in young plants. The combination of both viruses may be partly responsible for the reduction in the profitable life of asparagus plantings. Also, when plants are infected with both viruses, they become more susceptible to Fusarium wilt.
Comments on the Disease
Both viruses are transmitted by aphids. Asparagus virus II is also transmitted through seed and may be transmitted in pollen from male plants to seed produced by female plants. Asparagus virus II is more prevalent in older cultivars, such as Mary Washington. Asparagus virus II may be transmitted mechanically on harvest knife blades, mowers, cultivation equipment, or any other activity that moves plant sap from one plant to another.
Management
Plant virus-free seed grown from healthy plants or plant transplants grown from tissue culture to eliminate the viruses.
Organically Acceptable Methods
Purchase of virus-free seed or transplants is acceptable for use in an organically certified crop.