If the export ban is there, then the farmers will suffer. They will be forced to sell their produce at low rates, since there will be an oversupply at the local markets. This will keep the prices low for the consumers, but in the long run will do more harm than good. If the farmers incur losses, then in the future they will scale down the production, or form cabals to ensure higher prices. IMO, the government should not intervene in free market. Import/export bans make no sense in the 21st century, and they are ineffective.