Resistance of Napier grass clones to Napier grass Stunt Disease.
Napier grass (Pennisetum purpureum Schumach) is the major livestock fodder under intensive and semi-intensive systems in East Africa. However, the productivity of the grass is constrained by Napier grass Stunt Disease (NSD). The purpose of this study was to identify Napier grass clones with resistance to NSD. Seven introduced Napier grass, from the International Livestock Research Institute (ILRI) gene bank in Ethiopia, and 3 locally available clones in Uganda, were screened for resistance to NSD. Napier grass Stunt Disease severely infected plants tended to have more tillers (r = 0.84, P<0.001), but reduced biomass (r = -0.70, P<0.001) and height (r = -0.88, P<0.001). The reaction of the clones ranged from highly susceptible (clones 16795 and 16792), moderately susceptible (P99, KW4, 16806, 16803, 16785, local and 16814) to resistant (16837). Clone P99 was moderately susceptible to NSD but its harvestable biomass was least affected by disease infection, thus could be, in the interim, utilised in integrated NSD management as the search for more resistant clones is expedited.
Key Words: Disease severity, Pennisetum purpureum