January 23, 2004


Cucurbit Yellow Vine Disease- An Emerging Cucurbit Disease

Cucurbit yellow vine disease is a newly described disease, which can cause heavy crop losses in cantaloupe, pumpkin, squash, and watermelon fields. The disease has been reported from Oklahoma and it is believed to occur from the Midwest to the Northeastern states.

Symptoms. Symptoms of yellow vine generally appear during fruit set and become severe about two weeks before harvest. Leaves near the crown of the plant or entire plants turn pale green and then bright yellow. Yellowing and leaf death generally progress outward from the crown. Eventually, entire plants are killed. The key diagnostic features for yellow vine include a lack of external root or crown symptoms, and a light brown discoloration of phloem visible in cross section of the lower stem and roots. The distribution of the disease in is patchy, and edges of the field are often severely affected.

Causal agent. The bacterium Serration marcencens has been identified as the causal agent of yellow vine disease of cucurbits. S. marcescens is a gram negative bacterium producing creamy white, smooth, convex colonies on nutrient agar. It has been reported that the squash bug can transmit S. marcescens.

Disease management. At present, there are no satisfactory measures available for control of yellow vine of cucurbits. Controlling squash bug has provided some degree of disease control.

Click here to see some related pictures.