The evaluation of Ethalfluralin, Trifluralin and Pendimethalin efficacy of different doses on controlling of potato )Solanum tuberosum L.( weed

Chemical weed control is one of the most common weed control methods in potato field in the world and Iran. Herbicides which are using for potato fields include: Metribuzin, Paraquat, Pendimethalin, Rimsulfuron, EPTC, Solfosulfuron, Ethalfluralin, Trifloralin, Pendimethalin, Prosulfocarp, Metolachlor, and Oxadiargyl. In Iran, Metribuzin and Paraquat are recommended herbicides in potato field. Due to the limited number of herbicides registered, application time, number and variety of site, the objective of our research was to evaluate the efficacy of Ethalfluralin, Pendimethalin and Trifluralin for weed control and yield and component yield of potato. Trials were conducted in Ardabil Agriculture and Natural Resources Research Station in 2013. The experiment performed as does-response based on Randomized Complete Block Design with three replications and potato,s cultivar was Agria (common cultivar in Ardabil). Herbicides studied were Trifluralin (Treflan EC 48%) at 0.125, 0.25, 0.5, 1, 2 and 4 L/ ha, Etalfluralin (Sonalan EC 33%) at 0.125, 0.25, 0.5, 1, 2 and 4 L/ ha and Pendimethalin (Stomp EC 33%) at 0.25, 0.5, 1, 2, 4 and 6 L/ ha; also two treatment (with and without weeding) was considered as control. The weed sampling carried out at 20 and 60 days after treatment. Results showed that maximum reduction percent of total weed biomass at 20 days after treatment achieved by 4, 6 and 4 L/ha Ethalfluralin, Pendimethalin and Trifluralin, respectivelly and application 6, 4 and 4 Pendimethalin, Ethalfluralin and Trifluralin reduced more than 82 % at 60 days after treatment, respectivelly. The best treatment of reduction percentage of common lambsqurters biomass was 6 L/ ha Pendimethalin at 20 and 60 days after treatment that had not significant difference by 4, 4, 4 L/ha Ethalfluralin, Trifluralin and Pendimethalin, respectivelly. The maximum reduction percentage of redroot pigweed biomass was 4 L/ha Ethalfluralin. This treatment could reduce redroot pigweed biomass 97 and 91%, respectivelly. After weed free treatment the best treatment of yield per plant and total tuber yield was 4 L/ha Pendimethalin that cause to increase more than two fold. This study showed application 6 and 4 L/ ha Pendimethalin and Ethalfluralin created maximum reduction percentage of weed biomass at 20 and 60 days after treatment. Application 4 L/ ha Pendimethalin increased yield per plant and total tuber yield of potato more than two fold. Therefore, the use of Pendimethalin and Ethalfluralin herbicides is recommended for potato weed control and increasing potato yield.