Influence of NPK I5:15:15 fertilizer rates and vine training on profitability of Lima bean (Phaseolus lunatus L.) in Savanna zones, Nigeria

Abstract

The study objective was to see how profitable it was to grow climbing bean cultivars with NPK 15:15:15 application rates in Nigeria's northern Guinea and Sudan Savanna zones. Field trials were done at the Institute for Agricultural Research Samaru, Ahmadu Bello University Zaria and National Horticultural Research Institute (NIHORT), Bagauda sub-station research farm throughout the 2018 wet season (from the final week of May as rain began to the last week of November).The treatments consisted of two cultivars of lima bean (Ex-Manchok Brown and Ex-Manchok Cream), training (trained and non-trained) and four levels of NPK 15:15:15 fertilizer rates (0, 150, 300 and 450 kg ha^-1). The treatments were laid out in a randomized complete block design replicated three times. All lima bean production options were profitable at Samaru with trained Ex-Manchok Cream without fertilizer being most profitable (N476,858.4 ha^-1) with net return of N 2.84 per naira invested. At Bagauda all production options were unprofitable due to low crop yields (105-237 kg ha^-1): fertilizer and its application costs which accounted for 13.4 to 28.9% of total production cost in trained crop and 19.8 to 38.7% in non-trained. From this study it can be concluded that profitable and sustainable lima bean production, requires training of an adapted cultivar and application of 450 kg ha^-1 of NPK 15:15:15 compound fertilizer.