Superphylum Heterokonta Rank Species | Genus Peronospora Higher classification Peronospora | |
 | ||
Similar Peronospora, Septoria glycines, Diaporthe phaseolorum var sojae, Phakopsora pachyrhizi, Diaporthe | ||
Peronospora manshurica is a plant pathogen. It is a widespread disease on the leaves of soybeans and other crop plants. The fungi is commonly referred to as downy mildew, "leafspot", or "leaf-spot".
Contents
Symptoms
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.
Risk factors
The fungus spreads by oospores on diseased leaves and/or on infected seed. The disease spreads in environments with high humidity and favors temperatures between 20-22 °C.
Control
The disease is often controlled using fungicides such as mancozeb, maneb, or zineb.
