Fruit growth cracks
Every producer must have been or will one day be confronted with the appearance of growth cracks on melon fruits. This results in "bursts" located in the stylar zone of the fruits (figure 1). Note that these slits allow various molds to easily colonize the flesh and induce rot, such as Fusarium sp. (figure 2).
The exact cause of this certainly physiological condition is not known. It seems that plant food, and in particular their water supply, plays a role in promoting its expression. Indeed, it is observed in cultural contexts in which the plants have received too irregular irrigation, in "jolts": periods of humidity following periods of drought. It also rages following significant and unexpected inflows of water: heavy rains...
Note that all varieties do not behave in the same way when faced with these situations: differences in sensitivity may occur.
To more or less solve this problem, we cannot advise you enough to abandon the cultivation of varieties that are too sensitive and to try to better control the irrigation.