ASSOCIATION ANALYSIS AND CONTRIBUTION OF GROWTH AND YIELD CHARACTERS TO YIELD OF CASTOR IN BAUCHI STATE, NIGERIA

A field experiment was carried out at Abubakar Tafawa Balewa University teaching and research farm, Bauchi located in the Northern Guinea Savannah and Bulkachuwa village of Katagum LGA located in Sudan Savannah both in Bauchi State, during the rainy seasons of 2016, 2017 and 2018 to study the association of growth and yield characters and their contribution to the yield of castor. The treatments consisted of five nutrient sources (poultry manure, cow dung, chicken feather, municipal waste, mineral fertilizer) and a control and two varieties of castor (Ex-India 1 and 2), factorially combined to give 12 treatments and laid out in a randomized complete block design (RCBD) with three replications. The result of the experiment revealed a significant and positive relationship as well as direct and indirect contribution of characters to the yield of castor. Except leaf area index (r = 0.174*), number of capsules (r = 0.169*) and seed oil content (r = 0.139*) that were only significant at (P≤0.05), all the parameters measured were positively related to grain yield. Except net assimilation rate (r = -0.643**), days to 50% flowering (r = -0.485**) and height to first raceme (r = -0.345**) that had negative relationship with grain yield, all other parameters exhibited a strong and positive relationship with castor grain yield. The result further indicated that, the direct contribution of plant height to seed yield was positive and highest. It was further observed that, the highest direct and negative contribution was observed with height to first raceme. It also showed that, direct and positive contribution to seed yield among the growth characters was only observed through plant height and crop growth rate. Yield characters on the other hand, a direct and positive contribution was observed with highest from 100 seed weight. Based on the results of this findings, improving characters that exhibit direct and positive contribution can improve the yield of castor in the study area.