How to screen for submergence tolerance and avoidance: Two ways

1. Tolerance to complete submergence: Duration of submergence depends on several factors the most important of which are seedling age, water temperature, turbidity and light intensity. At IRRI, screening is commonly performed 30 d (= days) after transplanting of 21 d old seedlings or 30 d old seedlings with direct seeding. Both are conducted in artificial ponds. Water level should be raised fast and maintained to a depth of at least 1 m for 10 to 14 d as the standard period of treatment. To avoid severe conditions e.g. when water temperature is high or water is turbid, it is better to monitor the performance of the sensitive check and drain the water once the base of its stem start to soften.

 2. Submergence avoidance (Elongation ability): Treatment should start 30 d after transplanting of 21d old seedlings. Water level is usually increased at a rate of 5 cm/day up to 100 cm. The evaluation can be conducted at any time while the water level is rising or after reaching the maximum height of 100 cm. Lines that continue to elongate and keep pace with the rising water could be selected and evaluated for other agronomic and quality traits.

http://www.knowledgebank.irri.org/ricebreedingcourse/Breeding_for_submergence_tolerance.htm

thank you sir for constructive suggestion.

Thank you Muhammad. Compliments  for good initiative.