Watermelon Fruit Blotch

Watermelon fruit blotch Common name Watermelon fruit blotch Causal agent Watermelon fruit blotch is caused by a bacterial pathogen belonging to the genus Acidovorax. It affects several cucurbits, leading to blight and fruit rot. Scientific name Acidovorax avenae subsp. citrulli Symptoms & Signs The symptoms are majorly visible on the leaves, fruits, and seedlings. It is identified by water-soaked, necrotic lesions on the lower surface of the leaves and cotyledons. The lesions are surrounded by brownish-yellow chlorotic margins, especially near the midrib of the leaves. Necrotic lesions on the seedlings usually result in the death of the plant. Furthermore, the fruits also show water-soaked, greasy lesions that continue to grow with the advancement of the disease. The lesions may only be limited to the lighter stripes on the watermelon. Severe infection can cause cracking in the center of the lesion, resulting in fruit rot. Transmission It is a seed-borne pathogen and mainly spreads via infected seeds and transplants. High temperature and humidity favor the growth and spread of this pathogen. Time of concern Early spring to fall Common hosts Watermelon Melon Pumpkin Zucchini Cucumber