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Rice research institute experts urge delta farmers to choose paddy varieties suited for local conditions
With kuruvai cultivation under way in a few pockets of the delta and most areas still awaiting favourable conditions, scientists at the Tamil Nadu Rice Research Institute (TRRI), Aduthurai, have urged farmers to plan ahead for samba and thaladi seasons using region-specific, low-input paddy varieties.
TRRI Director K. Subrahmaniyan told The Hindu that variety selection must align with the delta's soil and climate. Citing TPS 5, a commonly used variety here, he said while it matures in 100 days elsewhere, it takes 125 days in the delta — causing delayed harvests, higher pest incidence, and increased costs. He warned against sowing short-duration varieties during samba season, calling it a common but expensive error.
He expressed concern over continuous cropping, especially thaladi immediately after kuruvai, which denies the soil a recovery phase. 'Without rest or organic enrichment, fertilizer response keeps falling,' he said. 'Twenty years ago, 10 kg of fertilizer gave results. Now, even 100 kg often falls short due to depleted soil health.'
To rebuild soil fertility, he recommended green manure crops such as Sunn Hemp and Daincha, to be incorporated before flowering. A well-managed green manure crop can contribute up to 130 kg of nitrogen per hectare and 20–30 tonnes of biomass. 'Only 10–15 kg of seed per acre is enough, and incorporation should be done 45–60 days ahead of kuruvai,' he said. Pulse cultivation after samba, he added, can improve soil health and help break pest cycles.
R. Manimaran, professor with expertise in pulses breeding, hybrid rice at TRRI, recommended kuruvai varieties such as ADT 53, 55, 56, and 57 — of which ADT 57 is suitable for direct sowing and ADT 55 offers Bacterial Leaf Blight (BLB) tolerance. ADT 53 is a good alternative to ADT 43 for parboiled rice, and ADT 59 is preferred for idly rice.
For saline and coastal tail-end areas, TRY (Tiruchi Rice) varieties 1 to 5 are ideal. For Samba, ADT 51 (155 days) and ADT 52 (145 days) are recommended, with ADT 52 noted for its strong non-lodging ability during adverse weather.
For flood-prone delta areas, he recommended CR1009 Sub 1, which can withstand up to 15 days of submergence during early growth.
For thaladi (October sowing), ADT 54 (an alternative to improved White Ponni), ADT 58, and ADT 60 — all in the 125–135 day medium-duration group — were recommended for their consistency when sown within the right window.
