Tuber Yield of Potato (Solanum tuberosum L.) as Affected by Different Dosage Applications of Rimsulfuron at Its Various Growth Stages

To study the efficacy of rimsulfuron, as a postemergent herbicide, on potato tuber yield (c.v. Agria), its components and control of weeds, a factorial field experiment based on randomized complete block design with 3 replications was conducted at Ardabil in 2014. The first factor consisted of seven different levels of rimsulfuron dosages (0, 5, 10, 20, 30, 40 and 50 g. a.i /ha), and second factor was its applications at three different potato growth stages (emergence, stolon initiation and tuber bulking). A weed free treatment was also considered as control. Statistical analysis showed that 50 and 40 g. a.i/ ha rimsulfuron applications reduced weed densities by 55.38 and 49.47 percent respectively, but their difference was not statistically significant. Among rimsulfuron application times, its application at potato emergence, resulted in highest reduction of weed density. The results also, showed that rimsulfuron application of 50 g. a.i/ha to the weed free condition, increased number of medium and large sized tubers and total tuber yield by 53.04, 59.45 and 20.51 percents respectively and decreased small sized tubers by 61.03%, but its effect on the number of tubers per plant was not significant. According to result of this research it can be concluded that rimsulfuron is an efficient herbicide to increase potato yield and control weeds of potato fields in Ardabil, and probably in Iran. Further research is needed to substantiate these results.