Effect of Water Stress and Potassium on Yield and Yield Components of Cumin (Cuminum cyminum L.)

In order to investigate the effects of water stress and potassium on some traits of cumin a split plot field experiment based on complete randomized block design was conducted during 2013 agronomic growing seasons in Zarand region. In this study full irrigation plus three water stress levels including, cut off irrigation from stem elongation stage to seedling growth stage, cut off irrigation from stem elongation stage to the reproductive stage and irrigation in grain filling stage allocated in the main plots and three various potassium amounts (50, 100, 150 kg ha-1 Potassium sulfate) were considered as sub plots. Results indicated that water stress had a significant effect on all traits. The highest effect of water stress was observed on seed yield and the lowest effect of that was observed on essential oil content. Also, potassium had a significant effect on seed yield and essential oil content. Totally, cut off irrigation in early stage of growth and 100 kg/haof potassium sulfate had the highest effect on seed yield.