Effect of organic manures on the early seedling morphology of Irvingia wombolu Vermoesen in the tropical rainforest of Nigeria

The study was aimed at evaluating the effects of four selected organic manures on the early seedling morphology of Irvingia wombolu. The experiment was undertaken in Asaba located in the tropical rainforest zone of Nigeria (60⁰ 12´ N and longitude 60⁰ 45´ E). The study consisted of four organic manure treatments, namely: Tithonia alone, Tithonia + pig manure, Tithonia + cow manure, Tithonia + poultry manure and control with no manure application. The five treatments were arranged in a randomized complete block design (RCBD) with three replicates. At 15 days after sowing (DAS) percentage of germinated seeds ranged from 95.45% (control) to 95.73 % (Tithonia + poultry manure). A mix of Tithonia + pig manure, Tithonia + cow manure and Tithonia + poultry manure increased seedling height by 3.9, 9.7 and 11.5 % respectively compared to Tithonia alone. The highest leaf number (9.03) and LAI (2.90) were observed in Tithonia + poultry manure. Stem volume of seedlings increased significantly (P<0.05) over the control with application of organic manures. Stem volume was found to be significantly (P<0.01) correlated with plant height (r = 0.988), stem diameter (r = 0.980) and leaf area (r = 0.976). The study recommends the use of Tithonia + poultry manure mixture for better performance of Irvingia seedlings.