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Yellow vine decline (Serratia marcescens) affects muskmelon, pumpkin, squash, and watermelon. Symptoms begin to appear approximately two weeks before fruit matures, although infection occurs several weeks before symptoms develop. Initial symptoms include stunting of plants and/or intense yellowing of foliage, which is followed by a slow decline in plant health. In some cases, a sudden collapse of vines may occur with no other symptoms. Vascular tissue from crowns of affected plants is often discolored (light brown). The pathogen is transmitted through feeding by the squash bug, particularly between seed emergence and flowering. Refer also to the section on squash bug. 

Yellow vine decline.

(Photo: Ric Bessin, University of Kentucky)

Management:

• Manage insects beginning at seed emergence or transplanting.
• Protect plants with netting or row covers until flowering. 
• Promptly remove and destroy diseased plant material.
• Rotate with nonhost crops for at least 3 years.

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