Incidences of fungal leaf spot disease in buffel grass (Cenchrus ciliaris) in some selected pasture farms in Tanzania

Abstract

• Buffel grass (Cenchrus ciliaris L.) is one of the important perennial forage grasses in the pasture farms of Tanzania. It is highly nutritious, drought-resistant, grazing-tolerant, and with rapid growth characteristics. Field observation of leaf spot disease in buffel grass was conducted during the months of April, May, and July 2012 at three pasture farms in Tanzania. Laboratory and greenhouse fungal pathogenicity studies for buffel grass seedlings were conducted at Sokoine University of Agriculture, Morogoro, Tanzania. This study was set to investigate the health status of buffel grass from selected pasture seed farms for screening seed-borne fungal species of economic importance. It was also set to establish the pathogenic fungi effects on leaves of buffel grass seedlings.The incidence of leaf spot disease in buffel grass was 54%. Fungal pathogens of economic importance that were detected in this study include Phoma spp (28.5%), Curvularia lunata (17.34%), Alternaria alternata (14.1%), and Bipolaris spp. (12.2%). Pathogenicity of Bipolaris spp. Phoma spp., Pyricularia grisea, Fusarium pallidoroseum, Exserohilum rostratum, and Nigrospora oryzae were confirmed on C. ciliaris seedlings. The highest disease incidence was observed on buffel grass seedlings sprayed with Bipolaris spp (40%), while the lowest disease incidence was observed on plants sprayed with E. rostratum (27.5%). In particular, the order of virulence of the pathogenic fungal species was Bipolaris spp > P. grisea > Phoma spp. > F. pallidoroseum > E. rostratum (40%, 37.5%, 35.0%, 32.5%, and 27.5%, respectively). All identified pathogenic fungi species are seed-borne and with reported ability to cause leaf spot diseases in several other tropical forage grass species. Further research on innovative technologies and practices for controlling fungal infectious diseases in buffel grass seeds and leaves is suggested.