Improving the efficiency of trifluralin herbicide by microcapsule formulation in weed control of tobacco (Nicotiana tobacum)

Reduce pesticides usage and improve efficiency of them can be achieved by the technology of controlled release formulations. This experiment conducted to investigate the efficiency of synthesized microcapsule formulation of trifluralin in Tirtash Research and Education Center (located in Mazandaran province, the north of Iran) during the 2014 growing season. The experiment design was three-way factorial arrangement on a CRD with three replications. The treatments consisted of the microcapsule and emulsifiable concentrate (Treflan® 48%) formulation in different doses, 50, 75 and 100 percent of recommended dose (0.6, 0.9 and 1.2 kg a.i./ha) and application methods, soil-incorporated pre-planting and pre-planting. Weeding and weed infest were prepared as control plots. Density and dry weight of weed at 40 and 60 days after tobacco transplanting and tobacco yield were measured during the growth season. Based on the relative abundance of weeds, Setaria viridis L. and Amaranthus retroflexus L. were dominant species. The experimental results show there were significant difference between formulation type, dose and method of application on density and dry weight of weed and tobacco yield. The effectiveness of MC formulation in each applied dose were higher than EC formulation. The 50% recommended dose of MC formulation had the same weed control effectiveness as 75% recommended dose of the EC formulation. The green foxtail and redroot pigweed control were about 72 and 69% in 50% recommended dose of MC formulation and about 79 and 65% in 75% recommended dose of EC formulation, respectively. Also 50% of MC formulation could increase yield as same as the 100% of EC formulation, 4.26 and 4.30 ton.ha-1, respectively. Soil incorporation of trifluralin was very necessary to achieve best efficiency.