The tobacco market changed once the buyout was enacted. The farmers saw which way the wind was blowing for the crop (prices had been dropping, costs kept rising, legislation kept getting more restrictive and they couldn't get people to do the work at either end of the season and mid-season to top the plants) so they took the money and transitioned to other crops. The markets changed from the tobacco auctions in the Spring to contracts for specific buyers (RJ Reynolds, Phillip Morris, etc.). That's not a bad system if you think about it but the factors I mentioned above played a big part in the ending.
There are still farmers who grow it (in Calvert up by Northern High School, down at Barstow near the Industrial Park are two I can think of that are main roads. Below Dunkirk along RTE 4, at least a couple years ago) in SoMD in all five Counties as well as on the Shore, although the guys over there switched to other crops decades ago for the most part. The Amish still grow it in St. Mary's but a lot of them have also switched.
Calvert Factoids: I don't know if Hagner Mister stopped growing it, but he once told me that he couldn't take the buyout since he was Assistant Secretary of Agriculture, and then later the Secretary, and it would have been a conflict of interest.
One of the reasons Judge Perry Bown sold his farm in Calvert and moved to Virginia was because of the laws on tobacco in this state.