Scientists at the Institute, who were working since 1987 to evolve suitablerice varieties compatible for large scale cultivation in the humid tropicsof these islands, have now introduced four varieties which are foundpromising due to their inbuilt tolerance to excess salt.

"These tolerant materials were evaluated in multi-locational trials infarmers fields over a period of eight years under the island conditions andresults were very encouraging. Now farmers in this area have started growingthese varieties," Cari director SPS Ahlawat told visiting newsmen from NewDelhi.

The institute has developed `IR9884-4-31E-PT', `MTU7633', `ITA249' and`BTS24' rice varieties for the region which have the potential to replaceexisting `C-14-8', a traditional low yielding variety being grown in about70 per cent of the rice cultivated area at present.

Recurrent evaluation under artificially stimulated conditions in thelaboratory and salt affected conditions in the field involving 3,600 strainsresulted in selection of these varieties, Ahlawat said.

Besides the rice varieties developed through conventional breedingapproaches, CARI has exploited bio-technological approaches to recovervarieties tolerant to excess salt, Ahlawat said. Among the new ricevarieties developed, BTS-24 was found to be the most promising which wasout-yielding the best High Yielding Variety (HYV) `Taichung Sen Yu' grown inthis area, he added.

The line has been tested in research farm as well as farmers field bothunder normal and saline soils across South, middle and North Andamans andwas found to be highly-adaptive to the available agro-climatic conditions ofthe Island.

BTS-24 has been nominated to All-India Co-ordinated Rice ImprovementProgramme (Aicrip), Hyderabad, for country-wide testing and release.

Concurrently, it is also being tested through the network of InternationalRice Research Institute (Irri), Philippines, Ahlawat said. This uniquevariety serves the dual purpose of cultivation both under normal and salinewater conditions which is an additional advantage to the uneducated farmerswho often empirically judge the salinity status of soil through theirexperiences, he said.

Cultivation of BTS24 rice variety would circumvent crop failure in coastalareas with normal soil which suddenly develops salinity owing to occasionaltidal flush or stagnation of saline water, Ahlawat said. The variety alsopossess moderate level of field tolerance to yellow stem borer, a seriousinsect pest emerging very fast in South and South-East Asia, for which thereis hardly any tolerant HYV available, he said.Besides BTS24, three sisterselections designed as BTS28, BTS18 and BTS13 were also found to have thepotential for cultivation under saline soil. These materials will be fielddemonstrated in various places at Soth, middle and North Andamans fromKharif 2000 season, Ahlawat said.

In Andamans, 12,000 hectares of low-lying area is under rice cultivation.This is found to be inadequate to meet the domestic demand. A major chunk ofthe requirement is brought from the mainland which has led to exorbitantcost, wastage and risk.