The agriculture industry in developed countries opposes free trade
This industry generally opposes free trade because it is an industry that involves fairly unskilled labor that can be easily outsourced abroad for lower wages. The threat for them is that the same work can be done abroad for lower wages and costs, and with a subsequently cheaper product. With free trade, these cheaper products imported from abroad can compete successfully with domestic producers, often with prices that domestic producers cannot compete with. This is why the textile industry in America is considered a "import-threatened" industry.