Why is watermelon not sweet when there is a lot of rain?

Watermelon grows fast with more water, but it is not sweet with less sugar accumulation.

The sweetness of watermelon is mainly determined by the amount of sugar such as sucrose, fructose and glucose. The formation of these sugars is inseparable from photosynthesis. Without strong photosynthesis, watermelon is not sweet. Many watermelon producing areas have the saying that "dried melons are sweet". Watermelon is not sweet if it encounters heavy rain or accumulated water before harvest.

In Xinjiang, Lanzhou, Gansu, Dezhou, Shandong, Dongtai, Jiangsu and other places, these places have a feature, the temperature difference between day and night is large. The temperature difference between day and night is not strong, which is not conducive to sugar accumulation. Watermelon is not sweet if its sugar content is low.

Method for improve sweetness of watermelon

Strong photosynthesis during the day can increase the transformation of sugar, accumulate more sugar and improve the sweetness of watermelon. It can be solved by increasing the light intensity and prolonging the light time, aiming at planting watermelon in greenhouse. In order to improve the light intensity, we can use low-temperature resistant and anti-aging drip-free greenhouse film, and often remove the dust on the film to enhance the light transmittance; Artificial lighting can be used to extend the lighting time.

Increase the carbon dioxide content. Watermelon needs carbon dioxide to help convert sugar during its peak growth period. Fresh horse manure can be accumulated in the shed, and propane and coke can also be burned in the shed to release dry ice and increase carbon dioxide content. Rational application of nitrogen fertilizer. Too much nitrogen fertilizer will affect the quality of watermelon, and too much nitrogen fertilizer will affect the transformation of sugar in watermelon.