Growth and Yield Responses of Three Cassava Varieties (Manihot esculenta Crantz) Using Two Compound Fertilizers in Humid Tropics, Rivers State, Nigeria

An experiment on the growth and yield responses of cassava (Manihot esculenta Crantz) using two compound fertilizer types was conducted at the Teaching and Research Farm, Rivers State University Port Harcourt between March 2021 and February 2022. The treatments consisting of three cassava varieties (TME 419, TMS 95/0289, TMS 96/0523) and two compound fertilizer types (NPK 20-10-10, NPK 15-15-15) and a control without fertilizer application were combined in a split plot arrangement with cassava varieties to the main plot while fertilizer types took the subplots, in a Randomized Complete Block Design (RCBD) replicated three times. Parameters evaluated were plant height and leaf number at four weekly interval starting at ten weeks after planting, also tuber number and tuber weight. Results show that cassava variety TME 419 interacting with NPK 15-15-15 produced the highest plant height (288.3cm) while TMS96/0523 without fertilizer application produced the lowest plant height(199cm) at harvest. Cassava variety TMS 95/0289 interacting with NPK 15-15-15 produced the highest tuber number per plot (241.3) and per stand (10.1) respectively. Cassava variety TMS 96/0523 interacting with NPK 15-15-15 produced the highest leaf number per stand (103.3). Application of NPK fertilizer especially NPK 15-15-15 enhances tuber number, leaf number and plant height. Cassava variety TMS 95/0289 produced the highest tuber number and tuber weight. Thus it is recommended that TMS 95/0289 be recommended to farmers as it produced highest tuber number and tuber weight. Also, fertilizer NPK 15-15-15 is a preferred NPK fertilizer as it produced high yield in tuber number per stand and tuber weight.