Response of seeds of four tropical weed species to some herbicides and gibberellic acid during germination

Abstract

The responses and viability of acid scarified seeds of four tropical weeds to gibberellic acid and seven herbicides including Galex, Gramoxone, 2,4-D, Atrazine, Simazine, Round Up amd Primextra in the laboratory were investigated.  The weeds used are Cassia occidentalis, Cassia obtusifolia, Cassia hirtusa and Calapogonium mucunoides.  100 ppm solutions of the herbicides inhibited germination of seeds in the four weed species. 50 ppm of 2,4-D, Atraxime and Primextra inhibited seed germination in C. occidentalis. 100 ppm of Galex and Atrazine reduced the viability of seeds of C. hirtusa to 0%. The germination rate was increased by 100 ppm gibberellic acid. Total percentage seed germination in herbicide-free seeds ranged between 75 and 90 percent.