To Evaluate the Effectiveness of the Reduced Doses of oxadiargyl (EC 30%) on Potato Yield and Yield Components at Different Growth Stages

In order to study the effectiveness of the reduced doses of oxadiargyl as a post emergence herbicide on yield and yield components in potato, a field experimental design was conducted at Alaroog Research Station in Ardabil. The factorial experiment was arranged in a Randomized Complete Block Design with three replications and two controls (weedy and weed free plots) on Agria the common cultivar in Ardabil. The first factor studied was oxadiargyl doses which were chosen at six levels (0.16, 0.33, 0.66, 1.33, 2 and 2.66 lit/ ha), and the second factor was oxadiargyl application timings at different potato growth stages including potato emergence, stolon initiation and potato tuber bulking. The results show that 2.66 lit/ha herbicide application reduced the weed density and biomass to 48.40 and 66.16 percent respectively. Among oxadiargyl application timing treatments, maximum reduction percentage of weed density and biomass was at potato emergence stage. Statistical analysis showed that application of different doses had significant effects on the potato plant height, main stem diameter per plant, yield per plant and total tuber yield per hectare. Herbicide application at the rate of 2.66 lit/ha increased main stem diameter per plant, yield per plant and total tuber yield per hectare to 36.85, 49.27 and 51.59 percent respectively; but maximum plant height was observed with 1.33 lit/ha oxadiargyl application. It is also indicated that among the herbicide application timings, potato emergence stage showed increase in potato plant height, main stem diameter per plant, yield per plant and total tuber yield per hectare maximally.