Tar-wattar direct seeded rice technique reduces weed

The Direct Seeded Rice (DSR) technology is not new to the farming community of the state, but it could not gain popularity due to the problem of uncontrolled weed growth and severe iron deficiency in paddy. To overcome the issues faced in DSR, ‘Tar-wattar DSR’ was recommended and has been successfully adopted by many farmers in the state.

There are two big cautions for the farmers—first, they should keep a hawk eye on soil moisture levels to counter soil moisture recession and sow the crop at the proper tar-wattar condition. Second, they should identify the present weed flora at its 2–4 leaf stage and select herbicide spray accordingly.

In ‘Tar-wattar DSR’, a major departure from the earlier practice is the delayed first irrigation, which is applied about 21 days after sowing. This has many added advantages, such as more saving in irrigation water, lesser weed emergence and infestation, reduced incidence of nutrient deficiency (especially iron) due to lesser leaching of nutrients and initial root establishment in deeper layers that retain more moisture because of the soil mulch on the surface. The technique also offers wider adaptability and yields are comparable with puddled transplanted rice (PTR).

As the paddy season approaches, expert Dr Jasvir Singh Gill, Agronomist from Punjab Agricultural University, shared his insights.

“Except sandy, loamy sand, all other healthy soils with access to good quality irrigation water are suitable for Tar-wattar DSR. Fields with freshly excavated or filled-in soil should not be selected for DSR. All basmati and non-basmati varieties recommended by Punjab Agricultural University are suitable for sowing under this technique,” said Dr Gill.

He further advised that after choosing the variety, farmers should use 8–10 kg of seed per acre. Soak the seed in 10 litres of water for 8 hours (maximum soaking up to 12 hours), then dry it in shade for half an hour to ensure early emergence. After drying, treat the rice seed with 3 g of Sprint 75 WS (mancozeb + carbendazim) per kg of seed. Make a paste of the fungicide by dissolving it in 10–12 mL of water and rub it on the seed.

“Farmers should go for need-based laser levelling of the field. After laser levelling, apply pre-sowing (rauni) irrigation and prepare the field when it reaches tar-wattar (good soil moisture) condition with shallow cultivation followed by two plankings and sow immediately. Field bunds to differentiate plots/kiyaras should be made before rauni irrigation, and when the field comes to tar-wattar, plot-wise sowing should be done sequentially,” he said.

Farmers are advised to prefer the ‘Lucky Seed Drill’, which sows rice and sprays pre-emergence herbicide simultaneously. Post-emergence herbicides should be chosen according to the weed flora present.

In a ‘Tar-wattar DSR’ field, the first irrigation should be applied about 21 days after sowing. Delayed irrigation also ensures weed suppression, as the dried-up surface layer discourages weed growth. After the first irrigation, water should be applied at 5 to 7-day intervals depending on soil type and monsoon rains. The last irrigation should be applied 10 days before harvesting.