Evaluation of reduced dosages of Rimsulfuron compared to standard dosages with nonionic surfactant on field bind weed (Convolvulus arvensis L.) in potato (Solanum tuberosum L.( field

In order to evalaute reduced dosages of Rimsulfuron (Titus 25% DF) efficacy with nonionic surfactant in comparison to standard dosages on field bind weed (Convolvulus arvensis L.) biomass, field expriment was carried out at the Sheikh Kalkhoran of Ardabil during 2015. For this purpose, a factorial experiment was performed in the base of Randomized Complete Block Design, in three replications on Agria cultivar. Expriment included standard dosages of Rimsulfuron (0, 10, 20, 30, 40, 50, 60 g a.i/ha), reduced dosages (0, 5, 10, 15, 20, 25, 30 g a.i/ha) which were used at one stage (potato emergence), two stages (potato emergence + stoloning) and three stages (potato emergence + stoloning + tuber bulking), with and without nonionic surfactant (0.2 L/ha). Fitting standard dosages without nonionic surfactant data by the sigmoidal or logistical three parameters equations showed, application of 18.70, 11.44, 7.18 g a.i/ha Rimsulfuron in one stage, two stages, three stages reduced 50% field bind weed biomass. ED50 of standard dosages and with nonionic surfactant were from 17.60, 7.52, 8.59 g a.i/ha Rimsulfuron in one stage, two stages, three stages, respectivally. Fitting reduced dosages of Rimsulfuron without nonionic surfactant data by the sigmoiidal or logistical three parameters equations showed ED50 dosages were 18.11, 12.06, 7.81 g a.i/ha in one stage, two stages, three stages, respectivally. Also, reduced dosages of Rimsulfuron ED50 with nonionic surfacant were 15.64, 10.55 and 7.45 g a.i/ha in one stage, two stages, three stages, respectivally.

Keywords:

Dose- response , chemical weed control , Adjuvant , weed biomass