Effect of mineral fertilizers on fruit yield and nutritional quality of tomato variety (Lycopersicon lycopersicum Mill) in Ogbomoso and Mokwa, Nigeria

Field experiment was conducted at the Teaching and Research Farm, Ladoke Akintola University of Technology, Ogbomoso and Niger State College of Agriculture, Mokwa, in 2013 cropping season to examine the effects of mineral fertilizers on fruit yield and nutritional qualities of tomato variety. The experiment had twenty seven fertilizer treatments namely: nitrogen (0, 30 and 60 in kg N ha-1), phosphorus (0, 25 and 50 kg P2O5 ha 1) potassium (0, 16.5 and 33 kg K2O ha-1) and their combinations, replicated three times. Treatment without fertilizer served as control. The experiment was laid out in Randomized Complete Block Design (RCBD). Data were collected on plant height, number of flowers, number of fruits and total fruit yield. The determination of fruit phytochemical contents at full ripening, 6 fruit samples were randomly selected per plot and analysed for nutritional qualities such as crude Protein, Carotene, Iron, Phosphorus, Potassium, Calcium, Lycopene, Magnesium, Vitamin C contents. Data was analysed using analysis of variance (ANOVA) SAS package and treatment means compared using Duncan multiple range test at 5 % probability level. External input of mineral fertilizer improved tomato yield and nutritional quality of tomato. Application of 60 kg N ha-1 + 50 kg P2O5 ha-1 + 33 kg K2O ha-1 gave the highest fruit yield (27.81 t ha-1) while control plot had the least (9.96 t ha-1). Nutritional qualities (Lycopene, phosphorus, potassium) were best at fertilizer rates of 60 kg N ha-1 + 50 kg P2O5 ha-1 + 33 kg K2O ha-1. In conclusion, external input of mineral fertilizer is necessary to improve tomato yield and nutritional quality. Plants fertilized with 60 kg N ha-1 + 50 kg P2O5 ha-1 + 33 kg K2O ha-1 responded better than other rates and therefore can be recommended for farmers to increase crop production within the study areas.