Effect of glyphosate and paraquat on seed germination, amino acids, photosynthetic pigments and plant morphology of Vicia faba, Phaseolus vulgaris and Sorghum bicolor

In agriculture, the use of herbicides is necessary to prevent or restrict the growth of weeds that affect the yields of crops such as cereals and legumes. Intensive agriculture relies heavily on the use of herbicides to increase crop yields and provide abundant, inexpensive, and visually appealing food. However, the distribution and persistence of these chemicals in the field can negatively affect the growth and physiological parameters of the crop. The objective of this study was to evaluate the effect of different doses of two widely used pesticides (glyphosate and paraquat) in the Meknes region of Morocco on seed germination, amino acid content, and photosynthetic pigments of Vicia faba, Phaseolus vulgaris, and Sorghum bicolor. Results showed that pesticide application decreased seed germination and seedling efficiency. Both compounds acted as inhibitors and reduced the growth of V. faba, P. vulgaris, and S. bicolor when applied in higher concentrations, 5.4 g/L for glyphosate and 4 g/L for paraquat, which are the recommended doses in agriculture. Besides, similar herbicide effects on photosynthetic pigments and amino acid content were observed, with decreases in these parameters at higher doses. Our research concludes that the application of glyphosate and paraquat to V. faba, P. vulgaris, and S. bicolor seeds negatively affected germination, photosynthetic pigments and amino acids.