NEW DELHI: The Supreme Court on Wednesday said that putting some people in jail for burning stubble could act as a warning to others.“Why don’t you think of some penalty provisions. If some people are behind bars it will send the correct message. Why don’t you think of some penalty provisions for the agriculturists,” the court said while hearing a suo motu case on vacancies in state pollution control boards and committees.The court also asked the Commission for Air Quality Management (CAQM), the Central Pollution Control Board (CPCB), and state pollution control boards to prepare measures to control air pollution within three weeks, ahead of winter when pollution usually rises.A bench of Chief Justice of India B R Gavai and Justice K Vinod Chandran questioned states about unfilled posts in their pollution control boards and directed Uttar Pradesh, Haryana, Rajasthan, and Punjab to complete appointments within three months.The same direction was given to CAQM and CPCB. The court, however, allowed six months for filling promotional posts in state boards, CAQM, and CPCB.The CAQM, set up by the Centre, is responsible for managing and improving air quality in the National Capital Region (NCR) and nearby areas, including parts of Punjab, Haryana, Uttar Pradesh, and Rajasthan.