Host Range of Sorghum Downy Mildew in Africa

摘要

Sorghum downy mildew [Peronosclerospora sorghi (Weston and Uppal) C.G. Shaw] is a major disease of both sorghum [Sorghum bicoloi (L.). Moench.] and maize [Zea mays L.] crops grown in tropical and sub-tropical regions of the world. The grain yield lossresulting from systemic infection, which causes sterility, can be devastating (Williams 1984). Collateral hosts have been implicated in the between-season survival of P. sorghi in the Americas (Malaguti 1977). Only species in the tribes Maydae, Andropogonae and Panicae have been confirmed as susceptible (Bonde and Freytag 1979, Karunakar et al. 1994). In Zambia, Pande and Singh (1992) found Sorghum hale-pense (Johnson Grass) infected with f wrghi adjacent to farmers' fields. This indicates wild grasses may play a role in the epidemiology of P. sorghi in Africa. The following experiment was undertaken to investigate the host range of an isolate of P. sorghi from Africa.