Abstract

Rajarajan (CO. 40) i. e. culture TNAU. 13493 a derivative of a cross between CO.25 and IR.8 was synthesised at the Paddy Breeding Station. Coimbatore during 1969 This variety has a duration of 165-175 days, and can replace the tall indica strain CO.25 which is grown in a large area in Samba (August-January) Thaladi or Pishanam (October-February) and late samba (November-March) seasons. Reduction of height to eliminate lodging, high harvest index for increasing the yield of grain, a duration similar to strain Co.25 and resistance to blast disease were the four main features of this variety. The results of the trials in cultivators holdings during 1974-75 samba seasons are reported in this paper. Data on the performance of CO.40 at the Research Stations, at Aduthurai. Pondicherry. Madurai and in several holdings of farmers in Thanjavur district revealed that this new variety was superior to C0.25 in yield. As against the average grain yield of 35 quintals/ha recorded for CO.25 in these trials. CO.40 gave 60 quintals which represents an increase of 72 per cent over Co.25.

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