EFFECT OF ORGANIC AND INORGANIC FERTILIZER ON GROWTH, YIELD AND FRUIT QUALITY OF EGGPLANT (Solanum melongena L)

Abstract

Egg plant (Solanum melongena L) is one of the important Asian Vegetables grown in Kenya for local and export market; hence effort to improve its productivity and quality should be emphasized. Declining soil fertility due to continuous cultivation of small holder farms and escalating cost of imported fertilizers and the need to conserve and build natural resource capital and biodiversity, has renewed interest in the use of local nutrient resources for soil fertility management in Kenya. The study was conducted at Bukura Agricultural college farm during the short (SR) and long rain seasons (LR) of the year 2009 and 2010 respectively. Eggplant seedlings were raised and transplanting 42 days after sowing. During transplanting, DAP and compost was applied while CAN applied three weeks later. The experiment aimed at evaluating the effect of combination between two levels of the recommended inorganic fertilizers (50% and 100% of research recommended rates (RRR) of 220 kgha-1 DAP and 600 kgha-1CAN)) with three types of organic manures on growth, fruit yield and quality of egg plant (Solanum melongena L) var. Black beauty. Split plot design with three replications was used, where two levels of inorganic fertilizers treatments (50%RRR and 100%RRR) were randomized in main plots while three types of organic manures; FYM, Compost (10-15tonha-1) and Tithonia (6 tonha-1) and control treatments were randomized within the subplots. Topsoil (0-20cm depth) and organic manures were sampled before transplanting seedlings and analyzed for chemical properties, pH, N, P, K, OC and CEC. 75 days after transplanting, determination of and plant height (cm) and fresh weight (g) of the plants was done and in the third picking the fruit length and diameter determined. Results showed that there was a significant interaction between of the two inorganic fertilizer levels and the organic manures. Increasing inorganic fertilizer from 50% to 100% of the research recommended rates (RRR) encouraged the vegetative growth of eggplants shown by plant height and fresh weight. Besides increasing the total fruit yield, fertilizer enhanced the fruit quality. The farm yard manure was considered the superior source of manure for obtaining the highest value of the parameters under study compared to compost and Tithonia diversifolia (tithonia). Soil fertilized with 100% recommended NPK combined with organic manures produced the superior growth of plants and the highest amount of total fruit yields. Farmers would benefit by incorporating 10-15 tonha-1 (1-1.5 kg/M2) of FYM combined with 110 kgha-1 DAP and 300 kgha-1CAN (83kg N ha-1 and 61.5kg P ha-1) to improve on the growth, yield and quality of eggplants. Hence training farmers on how to increase availability and preservation of FYM is critical.