In the defined geographical area, there are no cold winds during the day and the water is warm, which promotes the formation of pearly grains and allows long-cycle rice varieties to be sown without the risk of failure, making it possible to grow the varieties covered by the PDO, which derive their distinctive characteristic, namely their amylose content, from the geographical area. This gives the rice its highly esteemed cooking qualities, as it is the amylose content that determines whether it has the right balance between flavour absorption and firmness.