CHARACTERISTICS OF SOME FORAGE-GRASS DISEASES 11 





Net Blotch 



Net blotch, a fungus disease caused by 

 Helminthosporium dictyoides Drechsl., at- 

 tacks only meadow fescue. Early sjmrptoms 

 appear as irregular brownish areas on the 

 leaves (fig. 11). Lesions are marked with a 

 delicate netted pattern, and it is from this 

 characteristic marking that the disease gets 

 its common name. In the later stages of 

 infection leaves wither and die from the tip 

 toward the base. Conidia of the fungus are 

 borne on the lesions or on the withered leaf 

 tips. Conidia are subhyaline to yellow and 

 are typically straight, with three to five 

 septations. Net blotch occurs from late in 

 spring until fall, attaining its greatest severity 

 during midsummer. The disease is favored 

 by periods of humid, hot weather. 



i 



Figure 11. — Xet blotch 

 on meadow fescue. 





