Effect of Spacing and Chemical Fertilization on Growth, Yield and Nutritive Quality of Ravaya (Solanum melongena cv Baby Aubergine)

A study on the effect of spacing and chemical fertilization on growth, yield and nutritive quality of ravaya (Solanum melongena cv Baby Aubergine) was conducted in a 3 x 4 factorial experiment on the experimental plot at the Department of Horticulture, Faculty of Agriculture, KNUST, Kumasi. In a Randomized Complete Block Design, spacing and fertilizer constituted the factors, spacing being the main plot factor with 3 levels and fertilizer, the subplot factor with 4 levels. Data were collected on nutrient status of soil sample before the start of the experiment, vegetative and reproductive growth, marketable and unmarketable yields, nutrient composition of fruits and cost benefit analysis. Soil analysis indicated that the soil was ideal for the production of aubergine since all the nutrients were within the production range. Spacing did not affect plant height and canopy spread however, fertilization significantly affected plant height but not canopy spread. Applying 12g NPK + 5g S/A (F3) produced taller plants. Their interaction influenced plant height and canopy spread. Number of leaves and branches per plant were not influenced by spacing but were significantly affected by fertilization. Plants which received 12g NPK + 5g S/A (F3) had more branches and leaves than the control (F0). The interaction showed significant differences between some of them with the S3F1, S3F2 and S3F3 having more branches and leaves. Plant girth was neither affected by spacing, fertilization nor their interaction effect. Spacing had no influence on days from sowing to 50% flower bud appearance, neither on flower opening nor fruit set. Plants which were not fertilized (control – F0) and those fertilized with 5g Sulphate of Ammonia (F1) per plant produced flower buds, opened flowers and set fruits earlier than the F2 and F3 plants. On yield, the closest spacing (70cm x 50cm) S1 produced the highest number and weight of fruits per hectare but the least fruit yield per plant. With fertilization, the F3 plants produced more fruits per plant and per hectare. The interaction showed that the closest spaced plants (70cm x50cm), and the highest fertilizer rate 12g NPK+5g Sulphate of Ammonia (S 1F3) had more number and weight of fruits per hectare. The closest spacing S1 (70cm x 50cm) and its interaction with fertilizer F3 (12g NPK + 5g S/A), S1F3 recorded the highest total weight of export marketable and unmarketable fruits. Neither spacing nor fertilization influenced fruit length and diameter but for the interaction, the S3F0 plants had the least fruit length and diameter that significantly differed from the others. Total yield per harvest reached its peak at the fifth harvest and declined thereafter. The closest spacing (70cm x 50cm) produced the highest total number and weight of both marketable and unmarketable fruits per hectare while the widest spacing (70cm x 70cm) produced the least weight of unmarketable fruits per hectare. The highest fertilizer rate 12g NPK + 5g S/A (F3) produced more marketable and the least unmarketable fruits per hectare. The analysis of fruit samples showed that ravaya was found to be similar in nutrients to garden egg. With the cost of production and profit margin, the S1F1 treatment (70cm x 50cm) and 5g of Sulphate of Ammonia recorded the highest net profit.

Source: KNUST