1Department of Soil Sciences and Water Resources, College of Agricultural Engineering Sciences, University of Baghdad, Iraq
During autumn season of 2022, a field experiment was conducted at College of Agricultural Engineering Sciences, University of Baghdad to investigate the effect of silicon and abscisic acid spraying on sunflowers under various water stress conditions on growth, yield and quality of sunflower in Calcareous Soil.
The experiment involved three levels of water stress, with irrigation scheduled every 2, 4 and 6 days. Additionally, three concentrations of silicon 0, 2 and 4 mg L-1 and three concentrations of abscisic acid 0, 0.5, 1 mg L-1 was considered. The experimental design employed a randomized complete block design (RCBD) with a split-split plot arrangement with three replicates.
Results showed a significant effect of irrigation every 2 days exhibited superior performance, leading to peroxidase activity achieved 15.8 mg protein-1, catalase activity of 10.98 mg protein-1, abscisic acid concentration of 0.462 µg ml-1, silicon concentrations of 0.283%. The application of 4 mg L-1 of silicon proved to be superior, resulting in peroxidase activity of 20.35 mg protein-1, catalase activity of 18.58 mg protein-1, abscisic acid concentration of 0.473 µg ml-1, proline concentration of 12.46 µm g-1 , silicon concentrations of 0.246 % and seed yield of 6.064 Mg ha-1. The use of 1 mg L-1 of abscisic acid achieved superiority, yielding peroxidase activity of 20.12 mg protein-1, catalase activity of 19.05 mg protein-1, abscisic acid of 0.508 µg ml-1, proline concentration of 14 µm g-1, silicon at 0.271 % and seed yield of 6.136 mg ha-1.
Abscisic acid, Drought stress, Silicon, Sunflower
