Leaf spot of squash (Cucurbita sp.) caused by Xanthomonas campestris pv. cucurbitae

Abstract

Squash plants of the species Cucurbita maxima and C. pepo and of the Tetsucabuto variety (C. maxima x C. pepo) with necrotic spots on the leaves and cankers followed by soft rot on fruit were observed for the first time In the summer of 1994. Farmers considered the disease to be causing severe damage, reducing production, commercial quality and post-harvest life of the fruits. This situation was repeated in 1995 and 1996. Leaves and fruit with symptoms were brought to the laboratory of the Faculty of Agronomy, where a bacterium was isolated. The identification and pathogenicity test proved the disease to be caused by Xanthonomas campestris pv. cucurbitae. This is the first report of the presence of this bacterium in Uruguay.