Growth and yield of onion as influenced by organic and inorganic fertilizer in Edo rainforest of Nigeria
The current study was to determine the effect of NPK 15:15:15 and poultry manure on the growth and yield of onion plant (Allium cepa L.). Two field experiments were carried out at the Faculty of Agriculture Teaching and Research Farm, University of Benin during the 2010/2011 and 2011/2012 dry croppping seasons of October – March . The experiment was a factorial combination of four levels of NPK 15:15:15 inorganic fertilizer at 0, 40, 80 and 120 kg /ha NPK and four levels of poultry manure at 0, 5, 10 and 15t/ha laid out in a randomized complete block design (RCBD) with three replications. Each replicate had 16 plots making it a total of 48 plots. Data were collected on growth and yield characters and analysed. Results of this study indicated that there was a significant interaction between the poultry manure and NPK 15:15:15 fertilizer on some growth and yield attributes. Application rates of 80 kg/ha NPK 15:15:15 in combination with 15t/ha poultry manure enhanced the growth and yield of onion in terms of crop growth rate, chlorophyll content, harvest index and individual bulb weight of onion and significantly produced the highest yield of (29.55 t/ ha) in 2011/2012 and (28.17 t /ha) in 2012/2013. However, application rates of 120 kg/ha and 15 t /ha produced the highest (7.06 and 6.89 t / ha) shoot yield for 2011/2012 and 2012/2013 respectively .
Keywords: onion, manure, harvest index, crop growth rate,