1. Fertilization damages the roots: Sometimes when fertilizing the melon, the roots of the melon will be injured, which is one of the reasons why the melon becomes bitter.

2. Mixed planting with bitter melon: If bitter melon and bitter melon are mixedly planted, it will cause the bitter melon to have a bitter feeling. This is because insects pollinate the bitter melon during the growth period, resulting in bitter melon pollination. The bitter melon pollen will cause the bitter melon to become bitter.

3. Insufficient photosynthesis: If the melon does not receive sufficient light during its growth period, the degree of photosynthesis will not be enough. For example, some melons grow in places with dense vines and leaves and do not receive sufficient photosynthesis, which results in the bitterness of mature melons.