Effect of inorganic fertilizer and cattle manure on growth and yield of two

Low soil fertility is a major constraint to irish potato (Solanum tuberosum L.) production in most parts of Kenya. An experiment was conducted at Kenya Agricultural Livestock Research Organization (KALRO) Tigoni to determine the effect of inorganic fertilizer and cattle manure on growth and yield of Desiree and Kenya Mavuno potato varieties. The experiment was a split plot design with two main plots each with four subplots and three replicates. Varieties formed the main plots while treatments (NPK (23:23:0) 100kg acre-1, NPK (23:23:0) 50kg acre-1 plus cattle manure 1.6t acre-1, cattle manure 3.2t acre-1 and control formed the subplots. Data collected included, stem height, canopy %, tuber size and yield. Data was analyzed by Analysis of variance (ANOVA).First season, stem height was significantly different among all treatments, NPK gave the highest. Second season, NPK and NPK plus cattle manure was not significantly different. NPK gave the highest height. Canopy %, during the first season, NPK had the highest although it was not significantly different from NPK plus cattle manure. Second season, NPK had the highest canopy % and was significantly different. The best tuber size distribution resulted from NPK treatment. On tuber yield, first season NPK and NPK plus cattle manure had no significant difference. Second season, NPK was significantly different. In all tested parameters NPK treatment had better performance from the rest of the treatments and can be recommended in irish potato production.