Cucurbit Yellow Vine Disease

Cucurbit yellow vine disease (CYVD) is a relatively new disease of squash, cantaloupe, watermelon, and pumpkins.  Initial symptoms occur shortly before fruit maturity when foliage turns lime green, then bright yellow. Plants exhibit a gradual decline and stunted growth. The phloem of roots and crowns of diseased plants shows a yellow-brown discoloration. In other cases, plants suddenly wilt and collapse at flowering and fruit set. This disease is vectored by an insect causing symptoms to occur in small patches or edges of fields.

CYVD is caused by the bacterium Serratia marcescens, which can also be found in insects, humans, soil, and water. Cucurbit strains form a distinct group varying in physiological and biochemical properties. The disease is vectored by the squash plant bug and few details of its epidemiology are known. There is no evidence that the pathogen is seedborne; it appears to overwinter in its insect vector. Management of CYVD consists of controlling the squash bug vector, removing the insect’s overwintering habitats, and plowing cucurbit debris under after harvest.