Paclobutrazol Application Favors Yield Improvement of Maize Under Semiarid Regions by Delaying Leaf Senescence and Regulating Photosynthetic Capacity and Antioxidant System During Grain-Filling Stage

untreated control. Among the various paclobutrazol treatments, PS2 (300 mg L−1) treatment showed the most promising effects on enhancing the activities of antioxidative enzymes, delaying leaf senescence and improving the yield of maize. Thus, understanding this effect of paclobutrazol on delaying leaf senescence introduces new possibilities for facilitating yield improvement of maize under semiarid conditions.