Crop evolution and food mages

Scarterran has Lamarckian evolution to an extant. Traits inherited externally from environmental factors are sometimes passed on to offspring. While this effect can be seen in mortals and beasts it is more pronounced in plants.
Like real world farmers, Scarterran farmers will of course shape their plants naturally by picking the strongest and healthiest plants to harvest seeds for the next planting season from and this will over time select for tastier, heartier crops, but it is possible to speed this process up with a magical assist.

Medieval art of farm workers (public domain) by unknown artist

by Eron12 with Hero Forge

In every age, arcane transmuters and Plant specializing theurgists have magically altered plants to make them better suited to food production. While boosting the size of a melon can triple the mass of said melon, this will only boost the next generation of melons from the giant melon's seeds by a tiny percentage, but recasting the enlargement spell year after year will create gradually larger tastier melons.

In this way, most commonly domesticated food plants have been selectively shaped in the distant past by so called "food mages".