The star of the summer months is undoubtedly the juicy and sweet watermelon. Producers worldwide are seeking methods to improve the taste and quality of the fruit. In China, a peculiar technique has become widespread. Farmers place small to large stones on top of growing watermelons. What is the reason for this, and does it really make the watermelon sweeter? According to the experience of Chinese farmers, placing a stone on the surface of a growing watermelon causes the fruit to ripen faster and more evenly. The stone heats up during the day and gradually releases the heat at night, thus creating a more balanced microclimate around the watermelon rind. This heat effect is said to promote the accumulation of sugars, making the watermelon sweeter. The development of the watermelon is significantly influenced by the fluctuations in day and night temperatures. If the fruit experiences too much heat stress, it can hinder sugar formation. However, the stone acts as a natural heat ...