Timing Apply by air or ground before permanent flood.
Flood treated field as soon as possible after application. A delay greater than 5-7 days will result in reduced efficacy. Wait at least 24 hours after reaching flood level before seeding rice. Water level in the checks should be maintained at 3 to 4 inches with no exposed soil. Do not drain treated field for a minimum of 14 days after application, except where state regulation allows shorter water holding periods.