Clover yellow mosaic virus

The symptoms on the main natural host species of red clover (Trifolium pratense) plants include stunting with bushy leaves that have a mosaic appearance and yellowed veins, and on white clover (Trifolium repens) plants include yellow or light green leaf striping, stunting and distortion (Pratt, 1961; Jones et al., 1981). Additional symptoms present themselves on other crops and on experimental hosts.

The recommended control for virus diseases of Trifolium spp. in the Pacific Northwest include seeding clover in late summer or early autumn to reduce exposure to insect vectors of insect-vectored viruses, harvesting forage or seed only 1 year, and rotation with other crops, e.g., cereals, avoid planting a new seeding adjacent to an established field, destroy clover plants on ditch banks or waste areas (https://pnwhandbooks.org/plantdisease/host-disease/clover-trifolium-spp-virus-diseases).

On implements and bench surfaces, disinfectants with activity against potexviruses should be used. Infected plants should not be used for propagation and precautions to prevent distribution of seed from potentially infected plants should be taken.