The Integrated Application of Phosphorous and Zinc Affects the Physiological Status, Yield and Quality of Canola Grown in Phosphorus-suffered Deficiency Saline Soil

Abstract

Despite the soil could contain high amount of phosphorus (P), salinity reduce its availability for crop plants. Hence, farmers should practice several tactics to ameliorate P deficiency in soils. The current study aimed to assess the importance of zinc (Zn) supply for mitigating the deficiency of P for canola grown in saline soil. The effects of three Zn rates (0, 150 and 300 mg L⁻¹, Zn<inf>0</inf>, Zn<inf>150</inf> and Zn<inf>300</inf>, respectively) under three P rates (0, 36 and 72 kg P<inf>2</inf>O<inf>5</inf> ha⁻¹, P<inf>0</inf>, P<inf>36</inf>, and P<inf>72</inf>, respectively) on physiological status, yield and quality of canola were measured. Treatments were arranged in the strip plot design based on completely randomized blocks with three replicates. Findings exhibited that P<inf>36</inf> recorded the highest values of membrane stability index in the 2nd season, while statistically leveled P<inf>72</inf> for relative water content and chlorophyll fluorescence in both seasons. Zn<inf>300</inf> exhibited potent effect on all canola physiological traits in both seasons. In both seasons, P<inf>36</inf> × Zn<inf>300</inf>, P<inf>72</inf> × Zn<inf>150</inf> and P<inf>72</inf> × Zn<inf>300</inf> showed the maximum chlorophyll fluorescence and performance index values. Plots treated with P<inf>72</inf> achieved 70.0% increase in canola seed yield, greater than the untreated ones. Seed yield obtained with Zn<inf>300</inf> were higher than Zn<inf>0</inf> and Zn<inf>150</inf> by1.30 and 1.10 times in 2019/20 season and 1.23 and 1.05 times in 2020/21 season. The highest oil % was recorded with P<inf>0</inf> × Zn<inf>150</inf> and P<inf>72</inf> × Zn<inf>0</inf> in the 1st season and with P<inf>72</inf> × Zn<inf>150</inf> in the 2nd season.