Occurrence of Bacterial Fruit Blotch on Watermelon (Citrullus vulgaris) Caused by Acidovorax citrulli in the Republic of North Macedonia

In late summer 2019, Acidovorax citrulli the causative agent of bacterial seedling blight and fruit blotch (BFB) of cucurbit plants was first detected in a commercial watermelon production area in the village of Sopot, Kavadarci, North Macedonia. Later, in the summer of 2019 and also in 2020, A. citrulli was observed on watermelon fruits (Citrullus lanatus L., varieties “Bibo” and “Olakala”) in the Strumica region in the Eastern part of North Macedonia. Initial symptoms included water-soaked, irregular spots on the fruits that appeared greasy and dark olive green, eventually developing into brown lesions. Round, cream-coloured, Gram-negative bacterial isolates were obtained from symptomatic fruit tissue, which were slow-growing, nonfluorescent, aerobic, and oxidase-positive.