France is set to have the worst wheat harvest in the last 40 years due to excessive rainfall, with production potentially dropping by 27% below the five-year average. The country, the largest wheat producer in the EU, has seen yields and quality affected by continuous rains, lack of sunlight, and low temperatures, leading to disease development. The article also mentions extreme weather conditions damaging crops across Europe, with France's farmers seeking financial assistance from the government. Despite the poor forecast in France and a smaller harvest in Russia, wheat prices remain at their lowest in four years due to a good supply from the US harvest.