Yellow-brown spots on barley (helminthosporiosis)
Author(s): проф. д.с.н. Светослав Бобев, от Аграрния университет в Пловдив
Date: 26.01.2014
3413
Yellow-brown spots on barley (helminthosporiosis) - Dreshlera tritici-repentis develop in spring on both surfaces of the lowest leaves and, under suitable conditions, reach the flag leaf. Symptoms vary, and two manifestations may occur independently or in combination. The necrotic type is characterized by small, yellow-brown, necrotic spots that enlarge, becoming light brown with a yellow periphery and an eye shape. The chlorotic manifestation consists of rapidly growing yellow areas with a darker central part. The pathogen causing net blotch persists for the next season under the seed coat of harvested seeds and in plant residues. The first infections occur from infected seeds or from wind-dispersed ascospores, released from pseudothecia formed in plant residues. Conidia formed on the spotted leaves cause additional infections, which, in rainy weather, lead to the most severe damage.
