Herbicide Residues in Potato–Pearlmillet Cropping System in Western India

Herbicides have emerged as an important tool in management of weeds. Despite effective control of weeds in most agricultural systems, annually 10% of the world’s agricultural production is lost due to weed competition. A long-term herbicidal trial was conducted on potato–pearlmillet cropping system at the Anand Agricultural University, Anand to assess the efficacy of fluchloralin and metribuzin with or without application of farm yard manure (FYM). The effect of herbicidal treatments on crop productivity, microbial properties of soil and herbicide residues was studied. Results showed that potato tuber yield was not significantly influenced by the application of fluchloralin alone or with 10 t FYM/ha. Grain yield of succeeding pearlmillet was also not significantly influenced by continuous application of fluchloralin at 1.0 kg/ha with or without 10 t FYM/ha or rotated with metribuzin at 0.35 kg/ha with or without 10 t FYM/ha in potato crop. Herbicide residue analysis showed that fluchloralin applied in potato did not persist in soil and showed no change on soil physico-chemical properties. Although microbial flora particularly bacteria were significantly affected due to both herbicides, application of FYM helped to rebuild the microbial population by the harvest time of crop.