Central Rice Research Institute, Cuttack has developed a high yielding rice variety for medium/semi-deep water logged areas. Christened as ‘CR Dhan 501’ the variety is released by the Central Varieties Release Committee this year for Assam and Uttar Pradesh. With duration of only 155 days, its average yield is estimated at 4.0 ton per hectare. CRRI has another 11 varieties released for this particular ecology for cultivation in Orissa with yield potential ranging from 3.0 to 4.5 ton per hectare. Among these, Varshadhan, released in 2005 is a popular variety with yield potential of 4.0 ton/hectare. CRRI has identified suitable rice varieties for medium/semi-deep water logged areas in different parts of the country as well.
In our country, about 3.0 million hectare rice area is affected by water logging, mostly in the coastal region. The risk of frequent submergence due to flashfloods and water logging makes the ecosystem less responsive to better management. In these areas, water accumulates at depths of 25-30 cm for substantial period of the crop growing season. Water logging at the early stages of crop growth suppresses tillering and increases plant mortality. Poor drainage in water logged areas leads to accumulation of toxic substance (iron toxicity, sulphide injury etc.) and increase in incidence of pests and diseases.
‘As the crop management is a major problem under water logged situations, varietal improvement is the only alternate to increase the rice production and productivity’, said Dr. T.K. Adhya, Director, CRRI, Cuttack. To contain the water stagnation problem under this ecology, varieties should have some suitable features, such as height of 115-130cm, stiff culm, erect leaves, drought tolerance at seedling stage, submergence tolerance with less elongation and without culm elongation and strong seed dormancy. ‘Achieving higher productivity from this under fertilized otherwise high potential areas is thus an immediate need of the country, particularly in the eastern region’, he added.