Leaf Deformation (geminivirus): This disease is transmitted by whiteflies. The leaves are crinkled, misshapen and may have diffuse yellow areas. Both compound and simple leaves are affected. Infection has been seen only late in the growing season and there has been no detectable effect on yield.
Leafspot (several species of fungi): Curvularia senegalensis and Nigrospora oryzae produce round, reddish brown lesions with tan centers, while Exserohilum rostratum produces water-soaked or sunken lesions and causes some leaf chlorosis.
Powdery Mildew (fungus – Leveillula taurica): The symptoms are an extensive growth of white, powdery fungal mycelium on the upper leaf surface, followed by leaf defoliation and abortion of floral structures and early-stage seed pods. Tiny, dark spherical cleistothecia (fruiting structures) are produced on senescent leaves. This disease can diminish seed yield and reduce seed quality in susceptible varieties.