NO MIGRANT LABOURNone of the world's major rice exporting nations - India, Vietnam and Thailand - makes significant use of seeding machines.They have come into play in a big way in India this year because hundreds of thousands of migrant labourers from Bihar and Jharkhand states in the east did not arrive in the northern grain belt for the 2020 planting season due to the coronavirus lockdown.That pushed up the price of local workers and made it more economical for farmers to lease rice planting machines rather than pay for hired help, said Jaskaran Singh Mahal, a director at the Punjab Agricultural University.Farm wages have gone up by 1,500 rupees an acre to about 4,500 rupees this year, and growers need around half a dozen workers to.