The effects of salicylic acid on the germination and early seedling growth of pigeon pea (Cajanus cajan)

Abstract

This study investigated the effects of salicylic acid (SA) on the germination and early seedling growth of Pigeon pea (Cajanus cajan L., Fabaceae). Pigeon pea were sown in soils containing 5 mg/l, 10 mg/l, 20 mg/l, 30 mg/l and 50 mg/l SA and a control (0 mg/l). The treatment was applied to the plant for 6 weeks from the day of planting. It was observed that the leaflet area increased more in plants that received SA treatment in low concentration (0 mg/l, 5 mg/l, 10 mg/l and 20 mg/l) than in those with higher concentration (30 mg/l and 50 mg/l). The same result was obtained in the total chlorophyll content of the leaves and in average height of the plant (p<0.05). It was also observed that the number of leaves formed were more in plant that had little SA concentration. However, it was also discovered that at concentration below 10 mg/l, the growth promoting effect of SA declined. The study presents supporting evidence that optimum SA concentration required for maximum seed germination and early seedling growth in C. cajan is 20 mg/l. This finding will act as guide in the application of SA treatment in growing C. cajan.