Grapevine leafroll disease is caused by a complex of vector-borne virus species in the family closteroviridae. It is present in all grapegrowing regions of the world, primarily affecting vitis vinifera cultivars, hybrids, and rootstocks.
Leafroll-diseased vines typically experience decreases in net photosynthesis, which affect fruit quality and pigmentation. The disease often results in delayed maturity and yield reductions that cause significant economic damage. Since there is no cure for the disease, planting virus-free vines and removing sources of the virus from vineyards are critical management strategies. Mealybugs and soft scale move the virus from vine to vine; it is also transmissible by grafting.