Gummy Stem Blight: Mycosphaerella melonis

Symptoms

• Infected stems first appear water-soaked and then become dry, coarse and tan.
• Older stem lesions (dead tissue) reveal small black fruiting bodies (pycnidia) within the affected tissues.
• Large lesions girdle stems and plants wilt in the heat of the day.
• Stem lesions on melons exude a gummy, red-brown substance which may be mistaken for a symptom of Fusarium wilt.

Management

• Use of disease-free seed and transplants is essential to prevent serious crop losses.
• Periodic applications of fungicide like mancozeb @ 0.2% can help limit secondary infections, especially on fruits.
• Fall plowing and extended rotations with other crops can significantly reduce the amount of inoculum in infested fields.