Hossein Zahedi - Department of Agronomy, Islamic Azad University, Islamshahr Branch, Iran
Ali Badragheh - Department of Agronomy, Islamic Azad University, Islamshahr Branch, Iran
Amir Hossein Shirani Rad - Department of Agronomy, Oil Seed Crops Institute, Karaj, Iran
Davood Habibi - Department of Agronomy, Islamic Azad University, Karaj Branch, Iran

In order to study the effects of zeolite soil applications and selenium foliar applications on growth, yield and yield components of three canola cultivars under drought stress, an experiment was conducted in two growing seasons in 2006 and 2007. The study site was a field of the Seed and Plant Improvement Institute, Karaj, Iran. The experimental design was a randomized complete block arrangement in a factorially split plot with three replications. Irrigation factors were chosen at two levels, including normal irrigation and no irrigation, at the stem elongation stage. Zeolite was used at two levels, no application and 10 tons per hectare. Selenium was sprayed at three concentrations, 0, 15 and 30 grams per liter, from sodium selenate at the initial pod stage. These treatments were randomized in the main plots, while three canola cultivars (Zarfam, Sarigol and Okapi) were randomized in sub-plots. The results showed that different irrigation levels have significant effects on all traits, and drought stress significantly decreased all traits. The foliar application of selenium had significant and additive effects on plant height, number of pods per plant, number of seeds per pod, seed yield, biological yield, harvest index and oil yield. There was a significant difference between zeolite application and no application on all traits except percent oil and harvest index. Canola cultivars were different in all of the studied traits. Finally, zeolite and selenium applications in dry lands that are exposed to drought stress could be helpful for yield improvement and prevention of decreased yield.

Canola, Drought stress, Selenium, Yield and yield components, Zeolite