Deepwater rice

Traditional talls are varieties that are grown at water depths between 50 and 100 cm (20 and 39 in) and have developed to be taller and have longer leaves than standard rice.

This means when a field where rice is growing floods, accelerated growth in the internodal of the stem allows the plant to keep some of its foliage on top of the water.

In other regions of Mainland Southeast Asia, the main areas of cultivation are in Myanmar in the Irrawaddy Delta, in Thailand in the Chao Phraya[5] and Mekong in Vietnam and Cambodia.

[8] Deepwater rice is grown in tropical monsoon climates normally around river deltas and their floodplains mainly in backswamps and natural levees.

The nature of the flood is important for success of deepwater rice, with timing and the rate of rise of water affecting survival and crop density.

Sudden flooding, where a large volume of water enters the field in a short time, can lead to a high level of seedling death.

This means when a field where rice is growing floods, accelerated growth in the internodes of the stem allows the plant to keep some of its foliage on top of the water.

[13] A recent cultivar named Swarna Sub1 was developed via marker-assisted selection, with the ability to withstand prolonged periods of around 14 days beneath a flooded plain.

[14][15] Swarna Sub1 effectively enters a dormant, energy-conserving state upon being submerged in a flooded rice paddy, a process that involves the finely controlled metabolism of enzymes such amylases, starch phosphorylase and alcohol dehydrogenase, allowing the plant to survive with limited oxygen and sunlight unlike its standard variety relatives.