Field trials were conducted at the Institute for Agricultural Research Irrigation Farm, Samaru Zaria, in the northern Guinea savanna ecological zone of Nigeria in 2009/2010, 2010/2011 dry seasons to study the integrated effect of neem seed cake and inorganic fertilizer on tomato. The treatments consisted of three levels of NSC (0, 2 and 4 t ha-1) and four levels of inorganic fertilizer (0, ¼, ½ and Full Fertilizer recommended Rate (FFR, NPK 15:15:15) for tomato in northern Guinea savanna of Nigeria. The treatments were laid out in a Randomized Complete Block Design (RCBD) with three replications. Mean fruit weight and fruit yield were determined. Matured ripe fruits were analyzed for biochemical properties such as reducing sugars, total soluble solids, ascorbic acid and titratable acidity. Effect of treatments on soil properties were also determined by analyzing the treated soils after harvest. Results obtained showed that tomato responded positively to the treatments. Highest fruit yield of 14.54 and 19.70 t/ha were obtained from 2tons/ha neem seed cake + ½ Fertilizer rate in 2009/2010 and 2010/2011 respectively. Although the effect of complementary application of NSC and inorganic fertilizer on tomato was not significant among the treatments of such combinations, highest fruit yield increase over the control were 103.1% and197% for 2009/2010 and 2010/2011 respectively. Effects of treatments on ascorbic acid, titratable acidity, total soluble solids and reducing sugars were not significant. The concentrations of plant tissue N, P and K were higher than the control at the end of second year of experiment. In the first year of trial pH (H2O) varied from 6.2 to 6.7, whereas in the second year, it varied from 6.1 to 6.3. The values of soil OC and N increased over the years. Combinations of 2NC + ½ FR and 4NC + ½ FR proved superior for tomato fruit yield and mean fruit weight than other treatments in this study.
Keywords: Fertilizer, Inorganic, Neem seed cake, Tomato, Yield