Effects of Poultry Manure and NPK Fertilizer on Infestation of Musk Pumpkin (Cucurbita maxima) by Insect Pests

Field experiment was conducted during the 2013 growing season at the Teaching and Research Farm, University of Port Harcourt Nigeria, to evaluate the effect of poultry manure on the infestation of Musk pumpkin (Cucurbita maxima) by insect pests in the humid ecological zone of Nigeria. The study was laid out in a Randomized Complete Block Design (RCBD) with 5 treatments: Poultry manure (1.25 tons/ha, 2.5 tons/ha, 5.0 tons/ha), NPK (15:15:15), (300 kg/ha) and control (no treatment) and each treatment was replicated three times. Data on days to 50% germination, leaf damage, days to 50% flowering, fruit weight, number of fruits, number of insects and types of insect, were collected. The poultry manure and inorganic fertilizer reduced the number and weight of fruit, increased leaf damage (taken three times at the 3rd, 6thand 9th week after germination) and incidence of pests. The number of fruits was between 1.33 and 2.00 with fertilizer treatment and 2.33 in the control. The number of leaves damaged ranged from 1.76 to 1.98 with fertilizer treatment and 1.55 in the control at the 3rd week while at the 6th and 9th weeks there was no significant difference. The fruit weight ranged from 1.03 to 1.90 kg with fertilizer treatment and 2.37 kg in the control. Days to 50% flowering were not significantly affected. The growth and yield of C. maxima in terms of quality, market value and quantity were higher in control plots. The number of insect pests was not significantly affected by the treatments. Insects collected during the study comprised hymenopterans, coleopterans and hemipterans. Application of organic and inorganic fertilizer intensified insect pest infestation and decreased fruit yield. It is recommended that fertilizer application may not be necessary in well managed soils, but where necessary, 2.5 tons/ha poultry manure may be a safer recommendation for the cultivation of C. maxima.