Effect of timing and dosage in herbicide application on weed biomass in spring wheat
Lithuanian Institute of Agriculture, Instituto aleja 1, Akademija,58344- Kedainiai distr.Lithuania; e-mail: albinas@lzi.lt
Abstract:
The biological efficacy of herbicide Mustang (a.i. florasulam +2.4 D ester 6.25+452.5 g l-1) applied at doses 0.6, 0.45, 0.3 and 0.15 l ha-1 as compared to untreated areas was evaluated on the number and biomass of weeds in spring wheat in field trials at the Lithuanian Institute of Agriculture in 2003–2005. Herbicide was applied at the 3- leaf stage, at tilling, and at the beginning of stem elongation of cereals.The best efficacy on weed mass in all years of the experiments was achieved when theherbicide was applied at the 3-leaf stage and during the tilling stage of spring wheat. The weed biomass decreased by 82 to 92% in 2003 and 2004 and by 74–96% in 2005, from 0.3, 0.45 and 0.6 l ha-1 doses. When herbicides were applied using higher doses, 0.45-0.6 l ha-1.,during the spring wheat stem elongation stage (BBCH 31-32), the biomass of weeds decreased by 75–95%. When the lowest dose, 0.15 l ha-1 of the herbicide Mustang was applied at the beginning of the stem elongation stage of spring wheat, the efficacy on the total fresh mass of weeds was insufficient.
Key words:
2.4D, florasulam, spring wheat, weeds fresh mass