Two onion leaves on which sporulation of the downy mildew pathogen, Peronospora destructor, appears as if soil is adhering to the leaves compared to healthy leaves (lower two leaves).
Photo Source: Lindsey du Toit, Washington State University
Two onion leaves on which sporulation of the downy mildew pathogen, Peronospora destructor, appears as if soil is adhering to the leaves compared to healthy leaves (lower two leaves).
Photo Source: Lindsey du Toit, Washington State University