Indian Journal of Science and Technology

Abstract

Objectives: This study was carried out with the objectives of determining the growth potential of primed cowpea (Vigna unguiculata L.) seeds under different concentration of arsenic treated soil, specifically to ascertain the effects of salicylic treatment on growth properties of cowpea seeds treated with varying concentrations of arsenic acid. Methods/Statistical Analysis: Locally purchased seeds of cowpea treated with salicylic acid were grown on soil treated for 24 hrs by soaking with different concentrations (0.0, 50, 100 and 150 ppm) of arsenic acid before planting. 200 ml of the arsenic acid treatments were also applied immediately after planting and every fourth day for the next weeks of the study to the contaminated soil while control received distilled water. Germination percentage was recorded based on protruded radical and plumule and growth parameter such as plant height was measure using meter rule from base to the apical bud of the plant. The parameters were observed for three weeks. Mean and standard deviations were calculated for the values recorded in the study. Findings: Arsenic acid had negative effects on the rate of germination of both the treated and untreated seeds. The highest germination rates (50% and 75%) were recorded in the control of both the treated and untreated seeds. 20% and 25% germination was recorded for 50 ppm treated and untreated soil while 100 ppm and 150 ppm did not show sign of germination. Plant height was affected by the pollutant with control having highest height in both treated seeds as well as in the control. This was followed by 50 ppm concentration treatment with 100 ppm and 150 ppm showing no growth of plant. The research revealed that cowpea seeds were highly susceptible to the phytotoxic effects of arsenic acid and seed treatment with salicylic acid has no effect on germination and growth of cowpea seeds in contaminated soil. Applications/Improvements: This study therefore shows that the plant cannot serve as bioremediator in polluted environment. Therefore, appropriate measures should be taken to avoid arsenic contamination of cowpea farmlands. 

Keywords: Arsenic Contaminant, Plant Growth, Seed Priming, Vigna unguiculata L