ABSTRACT
This study investigated the effect of simulated acid rain (SAR) on the growth response, yield and mineral nutrient relations of Solanum macrocarpon. It was carried out in the screen house of the Department of Plant Biology and Biotechnology, Faculty of Life Sciences, University of Benin. Solanum macrocarpon plant was exposed to different levels of simulated acid rain acidified at pH 5.6 (control), 5.0, 4.0, 3.0, and 2.0 for a period of eight weeks under ambient conditions. The different pH levels were prepared using sulphuric acid and nitric acid in the ratio 3:1. The experimental design used was completely randomized design with five replicates per treatment.
Growth parameters such as plant height, number of leaves, leaf area, stem girth, number of flowers and fruits, macro and micro nutrient content and chlorophyll content were measured. The results obtained showed that growth parameters in plant subjected to simulated acid rain significantly reduced (p<0.05) when compared to the control (pH 5.6) treatment. The highest plant height (35.54 cm) occurred in plant treated with SAR of pH 5.0 while the least plant height (28.38 cm) was recorded in plant treated with SAR of pH 2.0. Fruits produced were adversely affected with the highest (3.00 g) at pH 5.6 and the least (1.00 g) at pH 3.0. No fruit was produced at pH 2.0. There was a gradual decline in the mean chlorophyll content as the acidity increased with the highest (72.50) at pH 5.6 and least (46.36) at pH 2.0. Morphological changes such as necrosis and chlorosis were induced in Solanum macrocarpon plant subjected to SAR. Macro and micro nutrient content of the plant such as Ca, Mg, Fe, K, P and N were lost. From this study, it was concluded that simulated acid rain (SAR) adversely affected the growth, yield and development of the Solanum macrocarpon plant.
