If farmers and growers can "set the price of their produce" like manufacturers and traders can...

Manufacturers and traders can set the price [ = (cost of goods + costs of sale + profit margin) ].

Farmers must set the price [ = (costs of production + costs of sale + costs of land and soil degradation + Remote Area Living Allowance + profit margin) ]

We can see that farmers and growers have to burden at least 2 extra costs: land and soil conservation, and remote area living. These costs are substantial and have follow-on effects on familes and children.

But as you say the fact is "they can't set the price" they have to accept greedy traders' offer. Sigh.