LAUSR

Abstract A field experiment was conducted in a randomized complete block design with triplicates to evaluate the effects of herbicide alachlor on weed, growth and yield parameters of maize. The seeds were subjected to preliminary germination study and the selected concentrations were applied (1.0, 2.5, 5.0, 7.5 and 10.0 ppm) followed by seed sowing and the treatments were compared with control. The maximum weed growth was recorded in the experimental site without herbicide treatment. At higher concentrations of the herbicide treatment the maize plants showed different types of morphological changes like improper leaf curling, malformation of leaf, stunted growth. The total weed dry weight showed considerable difference in all the concentrations treatments and least fresh weight was observed in weed free check (1.9 g) plot and the dry weight of weeds was also significantly different in different concentrations of herbicide. The weed control efficiency was increased as the concentrations of the herbicide increased and the maximum and minimum WCE (97.67 % and 28.97 %) was recorded in 10.0 and 1.0 ppm respectively. The weed index also found to be significantly increased from 6.87 to 91.7 % as the herbicide concentrations increased from 1.0 to 10.0 ppm respectively. The yield associated parameters like height of the plants, number of leaves and cobs, length of cobs, weight of cob and grains weight were found to be significantly different under different concentrations of herbicide treatment.