Effect of Plant Density and Land Race on the Growth and Yield of Sweetpotato in Northern Guinea Savanna of Nigeria

Field study was conducted at National Root Crops Research Institute out station Nyanya Research farm located at Zhewun Jidna Nasarawa State during 2007 and 2008 cropping seasons. The aim was to determine the effect of optimum plant population Density of sweet potato land races under improved management condition. Three Land races or Local varieties known locally as Katsina, Kunkudu, Dunku and TIS 87/0087 an elite variety that served as a check were used for the trial. The populations evaluated were 50, 000, 40,000, 33, 333, and 28,570, Plants ha-1. In both years result showed that Katsina gave the highest root yield of 42.0 and 26.8 t/ha, followed by the check variety TIS 87/0087 34.98 and 24.03 t/ha. This was not different statistically ( p< 0.05) in both years. Also 50,000 plants ha-1 gave the highest root yield across board. But in 2007,TIS 87/0087 gave the highest top yield at 50,000 plants ha-1 followed by 40,000 plants ha-1. In almost all other parameters evaluated the land race or Local variety Katsina out yielded the check variety and the other land races. It can be concluded that land races or Local varieties under improved management have capacity of out yielding some elite verities. The population of 50,000 plants ha-1 is recommended for higher root yield, while either 40,000 or 28750 plants ha-1 is recommended for any other farmers need other than root yield especially when there is scarcity of planting materials.