Downy mildew of Beans

The most visible symptoms of P. manshurica are pale green to light yellow spots that enlarge into pale to bright yellow lesions of variable size and shape. Lesions later turn grayish-brown to dark-brown with a yellowish-green margin that may eventually become entirely brown. Tufts of grayish to pale-colored sporangiophores on the underside of leaves easily distinguish the infection from other foliar diseases.