Besides rice and maize, wheat (Triticum) is one of the most consumed cereal grains worldwide. Bread wheat is categorised based on quality, which is largely determined by the hardness of the grain. A distinction is made between soft or hard wheat and wheat with white or red grains. Wheat is an annual crop and must therefore be sown every year. It is further classified by its growing season. Winter wheat is sown in October and harvested after about ten months. Spring wheat is sown early in the spring and harvested after six months. Russia, the United States, China, India and France are the largest producers of wheat.