Effect of Pre-Soaking on Seedling Establishment and Pretilachlor Tolerance in Four Rice Genotypes

This study aimed to investigate the effects of pre-soaking for 2 h before seeding on rice seedling establishment after 15-day spraying with pretilachlor. The cytochrome P-450 content, glutathione S-transferase (GSTs), and root activity were also determined. Seedlings of four rice cultivars with contrasting tolerance of pretilachlor were compared. Seed pre-treatment by pre-soaking increased the survivability and growth under pretilachlor spray and improved seedling establishment by increasing P-450, GSTs and root activities. Tolerant genotypes, super hybrid rice, responded better to pre-soaking in direct-seeded rice treated with pretilachlor. It is important for establishment in direct-seeded rice with pre-soaking seeds before sowing in improving emergence and seedling. The positive effect of pre-soaking was proved in all four rice genotypes. Seed pre-soaking will be effective in direct-seeded rice culture to protect rice treated with pre-emergence herbicide and control weedy rice.