The south-western Malwa, Bathinda, Mansa, Muktsar, Fazilka and Faridkot, is the cotton belt. It is drier than the rest of Punjab and cotton suits it far better than paddy.
Bt cotton, introduced in India in 2002, raised yields sharply and then ran into trouble. Pink bollworm developed resistance. In 2015 a whitefly outbreak destroyed a large part of the Punjab crop and was followed by a number of farmer suicides that were reported nationally.
Spurious pesticide sold to farmers ahead of the 2015 outbreak became a criminal case in Punjab.
Cotton acreage in Punjab has fallen substantially since, with land moving to paddy, which is exactly the wrong direction for the water table but is protected by procurement.
The Malwa cotton belt is also where the pesticide and health reporting that produced the phrase cancer train is centred. The connection between the crop, the chemicals and the health claims is asserted more confidently in the press than the evidence supports, and the belt's distress is not in doubt.
Cotton was the south west Malwa's crop and it collapsed repeatedly: to the American bollworm through the 1990s, and to whitefly across the belt in 2015.
Bt cotton was introduced to control bollworm and did, and it has no effect on whitefly, which is a sucking pest. The 2015 failure came on a crop that was supposed to be protected.
The debt from those failures did not go anywhere. The acreage has fallen and paddy has taken the land, in the driest districts of the state.