According to the law of supply, and demand, farmers will obtain the highest price for their products when

Farmers will obtain the highest price for their products when there is high demand of their product.

Explanation:

Farmers extract high prices from their produce when the demand for the produce is higher than the supply in proportion to it.

This means that the value of the produce has automatically increase as there is less of it and more people actually want it which is the basic rule of the supply and demand law which governs this scenario.

Thus farmers will get the highest price for their produce when the demand for it will also be the highest it can be.

Answer: when their is a high demand of the product