Performance of Pumpkin (Cucurbita maxima L.) varieties under defoliation stress and manure rate in Northern Guinea Savanna, Nigeria

Field trials were conducted during the 2012 rainy season at the National Horticultural Research Institute Farm, Bagauda (11⁰ 39^I N, 08⁰ 27^I E and 500m above sea level) and the Experimental Farm of the Institute for Agricultural Research, Ahmadu Bello University, Samaru, Zaria (11⁰ 11¹ N, 07⁰ 38¹ E, 684 meters above sea level) to study the response of two varieties of Pumpkin (Cucurbita maxima L.) to defoliation stress and farm yard manure rates. The treatments consisted of three levels of defoliation stress (0, 25 and 50%), three levels of farm yard manure (0, 5 and 10 t ha⁻¹) and two varieties (Yar-Madina and Ex-Ajiwa) of pumpkin. The treatments were laid out in Randomized Complete Block Design (RCBD) replicated three times. The results showed that at Bagauda defoliation at either 25 or 50 % had no significant effect on all the parameters evaluated except total dry matter (TDM) which significantly decrease at 50% defoliation at both locations. At Samaru, defoliation at 25 % resulted in significant decrease in the number of leaves per plant which was at par to pumpkin defoliated by 50%. Furthermore, at Samaru, defoliation by 50% resulted in significant decrease in leaf area, 100 seeds weight and fruit yield per hectare. Defoliation stress had no significant effect on pumpkin fruit length. At both locations the results further showed that application of FYM at 5 and 10 t ha⁻¹ recorded significantly higher but comparable leaf area and fruit yield ha-l. However, at Samaru the results showed that the application of FYM at 5 t ha⁻¹ was at par to the untreated control with respect to the total dry matter, number of seeds and 100 seeds weight. Based on this experiment it showed that defoliation stress by 50% had negative effect on pumpkin growth and yield but 25% defoliation might enhance fruit yield. The application of FYM at 5 t ha⁻¹ and defoliation at 25% might be recommended for pumpkin production in the Northern Guinea Savanna ecological zone of Nigeria.