Sending a clear “stick must follow the carrot” message to farmers whose refusal to stop stubble-burning has been a major factor behind air pollution in the national capital region, the Supreme Court on Tuesday suggested that the Centre stop buying their crop so that they are denied the benefit of minimum support price (MSP). The bench, also emphasised that the Centre and Punjab government must try to promote alternative crops to replace rice cultivation which has depleted water levels in the state and leads to stubble burning.