Can be obtained from plant breeding at your fences using Tomato, Paprika, Wheat and Corn

There is a daily quest giving you optional item:
- Fruit of the Sun
- Fruit of Enchantment
- Fruit of Perfection
- Fruit of Destruction
[Alchemy] Learning Never Stops #2

But you first need to finish a small questline, asking you to bring... 1 Fruit of the Sun! Then, to do 3 Alcemy quests.
So, the first Fruit of the Sun needs to be bred with a fence or bought at Auction House (hard to get).

Wayne, The Kid fishing in the river, behind Ashrogue (two girls are by a barn, you walk past them to get to the kid) gives out some nice Alchemy/Farming quests that require harvesting several of the "fruits". you start with fruit of crimson flame, and work down the line. See https://bddatabase.net/us/npc/582/ - BTW- I got my fruit of the sun breeding spec paprika to make more spec paprika...just sayin'