Incidence of Pearl Millet Diseases in Relation to Time of Sowing in Niger and Nigeria

摘要

Pearl millet [Pennisetum glaucum (L.) R. Br.] is widely grown in the Sahelian and sub-Sahelian Zones of Niger and Nigeria. Downy mildew [Sclerospora graminicola (Sacc.) J. Schrot.], smut (Tolyposporium penicillariae Bref.), and ergot (Claviceps fusiformis Loveless) are the three widespread diseases of pearl millet in Niger and Nigeria (Werder and Manzo 1992). Downy mildew is the most important disease, and yield losses of up to 50% have been reported from western Africa (Singh et al. 1993). Other diseases, especially smut and ergot, though of minor importance, can cause substantial yield losses in certain areas, environments, and genotypes (Thakur and King 1988ab). Despite the yield-reducing potential of downy mildew, smut, and ergot, their incidence has rarely exceeded economic threshold levels in most of the farm-ers' fields in Nigeria and Niger. Several reasons including genetic resistance to these diseases in the local landraces/cultivars and traditional cultural practices, probably result in low incidence of these diseases in these countries. The results of a study aimed at assessing the incidence of downy mildew, smut, and ergot in relation to date of sowing in the farmers' fields in Nigeria and Niger is reported.