No abstract

Two pot experiments were carried out at lath house in the Nursery of Ornamental Plants, Hort. Dept., Zagazig Univ., Egypt during the two spring consecutive seasons of 2018/2019 and 2019/2020 to study the effect of water stress (irrigation at 100, 75 and 50 % from field capacity), antioxidants type [(distilled water as control, 4 g/l of calcium carbonate (CC) and 30 g/l of kaolin (Ka)] as foliar applications and their interaction treatments on growth parameters, physiological traits, drought resistance percentage and some chemical constituents of paulownia seedlings. Plant height, stem diameter, leaf number per plant, dry weight of leaves per plant, drought resistance index, wood density and total chlorophyll content decreased significantly with increasing drought treatments from 100% to 50 % field capacity. However, water stress significantly increased soluble sugar content and proline content in leaves compared to full irrigation treatment. Furthermore, using each calcium carbonate or kaolin significantly increased all abovementioned parameters compared to control (sprayed with distilled water) in both seasons. Generally, it could conclude that 30g/l Ka showed a uniform influence in alleviating of Paulownia tomentosa growth inhibition and its wood density under moderate water stress condition with increasing in drought resistance percentage to reach 105.68 and 102.09 % in the first and second seasons, respectively.