The Response of Canola (Brassica napus L.) Cultivars to Different Soil K/Mg Ratios in Greenhouse Conditions

To investigate the effects of different levels of available potassium (K) and magnesium (Mg), and their interactions, on the growth characteristics of canola cultivars, a factorial experiment was conducted using a completely randomized design (CRD) with three replications in a pot culture. The first factor consisted of five combinations of the K to Mg ratio (existing conditions, ۸۰%, ۹۰%, ۱۱۰%, and ۱۲۰% of the existing condition) by adding potassium or magnesium sulfate. The concentration of available K+ and Mg۲+ in the existing conditions of soil was ۲۳۷ and ۲۰۶ mg kg-۱, respectively (K+/Mg۲+ ratio ۱.۱۵). The second factor included three canola cultivars (Zafar, Dalgan, and Hyola۵۰). After eight weeks (prior to flowering), the plants were harvested and shoot dry weight (SDW), the concentration of K, Mg, sodium (Na), and calcium (Ca) in the soil, shoots, and roots were measured. Based on the results, the Hyola۵۰ cultivar preferred further amounts of K+ to Mg۲+ (۱۱۰%). Still, the Dalgan cultivar preferred higher amounts of Mg۲+ (۹۰%) (۱۰.۸ and ۹.۶ gr pot-۱ SDW, respectively, for Hyola۵۰ and Dalgan). The highest K concentrations in the shoots of the Dalgan (۵.۱۰%) and Zafar (۴.۴%) cultivars were observed at the ۱۲۰% ratio. The K concentration in the roots of all cultivars (۰.۹۲۸%) was lower than that in the shoots (۴.۱۳%). The Hyola۵۰ cultivar demonstrated a greater need for K+ than Mg۲+ in the soil and was found to be less K-efficient compared to the Dalgan and Zafar cultivars. It is not suggested to maintain a consistent K+/Mg۲+ ratio in the soil for all canola cultivars.

کلیدواژه ها:

Canola ، Magnesium ، Potassium ، Root ، Shoot ، Soil