Fertilizer Rate for Optimum Growth and Yield of Egusi Melon (ColocynthiscitrullusL.)/ Hot Pepper (Capsicum chinense, Jackquin cv. rodo) Intercrop

The use of chemical fertilizers as a supplemental source of nutrients has been on the increase but they are not applied in balanced proportion by most farmers [1]. Also, fertilizer requirements of the mixed intercropping systems have been a matter of conjecture; some studies had suggested that fertilizer requirements of the dominant component be applied [2], others recommend that the sum of the sole crop requirements, be applied [3]. Teriah [4], however, stated that both practices have proved either inadequate or wasteful. In this experiment the effects of different rates of NPK 15-15-15 fertilizer application on growth and yield of hot pepper and Egusi melon in an intercropping system was examined to determine optimum rate for production. The experiment was carried out at the Teaching and Research Farm of the Federal University of Agriculture Abeokuta, in the south western part of Nigeria. It took place from March to October 2017 during the growing season. The experiment was laid out in a Randomized Complete Block Design (RCBD) with 5 treatments (fertilizer rates) and 3 replicates. Treatments were; 0, 100, 200, 300 and 400 kg/ha of NPK 15-15-15 applications. Plot size was 3m by 3m with a 1.5m gang way round each plot to reduce inter-plot effect. Data were collected on growth parameters at 6 weeks after treatment (WAT) and continued at two-week intervals until 10 WAT. Four plants each of pepper and Egusi melon from the inner rows were randomly selected and tagged for the purpose of data collection. Data on yield were also collected at ripening. Analysis of variance (ANOVA) was carried out on each observation and the Least Significant Difference (LSD) was used for means separation (P≤0.05). The effects of fertilizer rates showed significant difference on pepper plant height, number of leaves, number of branches and leaf area. However, there was no significant difference in the effect of fertilizer rate on days to 50% flowering of pepper. Number of vines and vine length of Egusi melon were significantly different in their responses to fertilizer rates but the leaf area and days to 50% flowering of melon were similar at the various treatment levels. Meanwhile, total fruit yield of pepper, number of Egusi melon pods per hectare and the dry matter yield of Egusi melon showed significant difference. It was concluded from the study that the growth and yield of pepper and Egusi melon in intercrop increased with increase in fertilizer rate up to 400Kg/ha of NPK (15:15:15). However, higher fertilizer application rates should be explored in future studies for a better yield increase. These studies should be carried out with various compositions of inorganic and organic fertilizer application rates to ensure sustainable fertilizer application and to also preserve the natural fertility of the soil.