Effect of NPK Fertilizer on Fruit Development of Pumpkin (Cucurbita pepo Linn.)

The effect of NPK fertilizer on pumpkin fruit development was studied for two cropping seasons in 2010 at the Teaching and Research Farm, Obafemi Awolowo University, Ile-Ife, Nigeria in 2010. The experiment was a randomized complete block design. The plants were treated with six NPK rates (0, 50, 100, 150, 200 and 250 kg/ha). Data on fruit weight, circumference, length and dry matter were obtained at 7, 14, 21 and 28 days after fruit formation. Increasing NPK fertilizer enhanced the parameters evaluated across the sampling periods. Fresh fruit weight (g/fruit) in control was 39g, 123g, 822g and 1059g and this increased to 80g, 370g, 1350g and 1630g at 7, 14, 21 and 28 days after fruit formation respectively at 100 kg NPK fertilizer rate. Across the NPK levels, pumpkin fruit growth curve was sigmoid. The fruit took approximately 22 days from fruit formation to fruit maturity across all the NPK fertilizer levels. In conclusion, excessive NPK supply did not significantly increase the rate of fruit growth or the fruit size. Fruit growth duration of pumpkin was not influenced by NPK fertilizer application