Effect of Preplant Application of Post Emergent Herbicide Glyphosate on the Events of Germination, Growth and Biochemical Composition of Blackgram Seedlings

Abstract

Weed causes heavy yield loss when it competes with crops especially for light, water, nutrient and space. In crop production, weed management is a necessary operation to get a higher yield. Manual weeding operation is an easy and environmentally friendly method but it increases the cost of cultivation and makes the crop production practice a non-profitable business venture. Under this situation, the herbicide can be used as the most practical and effective alternative means of weed control. In intensive agriculture heavy use of herbicide affects the growth and biochemical composition of the crop. The objective of this study was to find out the effect of pre-plant soil application of post emergence glyphosate on the germination, growth and biochemical composition of blackgram seedlings. Results showed that glyphosate 1000 ppm did not significantly affect the germination of blackgram seeds. However, the higher concentration of 1000 ppm affects the root (1.08 cm) and shoot length (6.16 cm) compared to control (6.16 and 12.27 cm, respectively) and the lower concentration at the rate of 10 ppm enhance the root (6.26 cm) and shoot length (12.49 cm). Soluble protein content was higher in glyphosate 1000 ppm (70.60 mg g-1) compare to control (59.40 mg g-1). The finding concludes that the pre-plant application of post emergence herbicide glyphosate didn’t affect the germination. However it has reduced the root and shoot length of blackgram when applied at higher concentrations. Contrary to the higher dose the lower dose of glyphosate stimulates the growth and development of blackgram seedlings.