Yield of Raphia Hookeri (Mann and Wendl) as Influenced by Combined Application of Poultry Manure and NPKMG 12:12:17:2 Fertilizers in Fresh Water Swamp

The study investigated the impact of combined application of poultry manure and NPKMg 12:12:17:2 fertilizer on Raphia hookeri palm sap production, with a view to determining the optimum fertilizer rates required by R. hookeri for optimum yield. The trial was conducted at the Nigerian Institute for Oil palm Research (NIFOR) Raphia experimental station, Otegbo, Delta State. It was a 2 x 4 factorial arrangement in a randomized complete block design (RCBD) in three replicates. Data were collected on yield traits such as number of green leaves cut, number of spadices, height at tapping, percentage of flowering palms, duration of tapping and palm sap yield. Data generated were subjected to analysis of variance (ANOVA) and significant means were separated using Duncan’s new multiple range test.(DNMRT) The result indicated that combined application of poultry manure and NPKMg fertilizer at varied rates increased soil extractable nutrients which enhanced Raphia hookeri sap yield over that of the control palms that were not fertilized. Combined application of poultry manure and NPKMg rates showed a progressive significant effect on all parameter measured except on duration of tapping. Highest palm sap yield (1140.6 Litres/palm) resulted from the combined application of 1.0kg poultry manures/palm and 1.0 Kg NPKMg/palm on the same palm. The lowest palm sap yield (345.2 Litres/palm) was obtained from the control plot (zero application). Palm sap production of Raphia hookeri increased as combined application of poultry manure and NPKMg rates increased until optimum rates of 1.0 kg poultry manure and 1.0 kg NPKMg/palm/year. At higher rates of combine application of poultry manure (1.0kg) and NPKMg (1.5kg)/palm/year, increase in the yield of other parameters and palm sap were not significant. The increase in sap and other yield parameters of R. hookeri when treated with combine application of poultry manure and NPKMg 12:12:17:2 fertilizer over that of the control is an indication that optimum yield of R. hookeri can be achieved when relevant nutrients are provided.