Angular Leaf Spot of Cucurbits Pseudomonas syringae pv. lachrymans
A bacteria that causes small, water soaked spots on leaves and grow to about 3 mm diameter then become brown and angular on the upper surface and shiny white underneath. Eventually the centres may dry and crack and fall away leaving a hole in the leaf. Lesions may also appear on petioles, stems and fruit. Immature fruit may drop off and mature fruit may develop a brown rot underneath the spot, which may dry to leave a white crusty residue.