Dry matter accumulation and growth analysis of Jatropha curcas L. as influenced by application of poultry manure and cow dung in Nigeria
Growth and yield of Jatropha curcas are low due to poor soil fertility and agronomic practices. An experiment was conducted at the Crop Garden of the Department of Crop Protection and Environmental Biology (CPEB) University of Ibadan on dry matter accumulation and growth analysis of Jatropha curcas as influenced by application of manure. Poultry Manure at 10, 20 and 40 t/ha and Cow Dung at 10, 20 and 40 t/ha (P5, P10, P20, P40 and C5, C10, C20, C40) with control (0 t/ha, M0) were evaluated (5 kg soil; 1 plant/pot)in a Completely Randomised Design. Dry weight and leaf area were obtained at monthly intervals to calculate: Relative Growth Rate, Net Assimilation Rate, Leaf Area Ratio and Leaf Area Duration using the formulae of Roderick (1978).The result showed that treatments P40, C40, P20 and C20 had the highest leaf dry weight (47.67g, 48.71g, 48.91g and 48.11g), while control had the least(23.30g), P40 had the highest stem dry weight (89.13g) which was not significantly higher than stem dry weight of C40 (86.56g), P20 (85.95g) and C20 (80.85 g) and control had the least stem dry weight of 51.78g.Treatment C40had the highest root weight (40.50g) and control had the least value of 25.41g.The net assimilation rate (NAR), relative growth rate (RGR), leaf area ration (LAR) and leaf area duration (LAD) showed that the RGR were higher between 6 and 8 weeks across all the levels. The NAR increased as the level of manure increased. Leaf area duration increased as the plant grew older across all levels while P5, C5 and control had the least. Leaf area ratio was 20.14(cm2/g) on control and 33.49(cm2/g) and 39.54 (cm2/g) on P40 and C40 respectively at last observation. Application of manure up to 20t/ha increased the dry matter accumulation and growth of Jatropha curcas.
Keywords: Jatropha curcas, Organic manure, Biodiesel, Environmental sustainability