Phomopsis black rot of cucumber caused by Phomopsis cucurbitae . A leaf hair is shown for size comparison. The pycnidia cannot be distinguished from those of Phoma cucurbitacearum , the gummy stem blight pathogen. Powdery mildew caused by Sphaerotheca fuliginea . A leaf hair is shown for size comparison.
Colonies form on succulent green tissue, leaves, and stems.
Target leaf spot caused by Corynespora cassiicola . A leaf hair is shown for size comparison. Conidiophores are produced on the upper and lower surfaces of leaves.