Board Thread:Wikia Discussion/@comment-27279544-20170528163214/@comment-26275332-20170608012425

Treasure bonuses work differently than weapons/summons, the bonus treasure you get is determined solely with RNG, there's nothing you can do about it. You can't reset bonuses on those because treasures themselves are different to weapons and summons.

Also +1 doesn't mean +1 stat or anything, +1 means you have 1 extra of the item, for example, you got a wheat stalk plus another wheat stalk, so you get 2 wheat stalks instead of 1.