downy mildew of basil

Downy mildew-The upper leaves may exhibit a chlorosis where infection has occurred. On the underside of the leaf, a gray sporulation may be observed under moist conditions. 

Figure 1. Downy mildew of basil. Upper side of leaf. Figure 1. Downy mildew of basil. Upper side of leaf.
Figure 2. Downy mildew of basil underside of leaf showing sporulation. Figure 2. Downy mildew of basil underside of leaf showing sporulation.