未熟: Immature skills and unripe fruit
Read the target of 未熟 to distinguish skills that are not yet sufficiently developed from fruit that is not ripe, preserving basic practice and fruit left unharvested.
Skills that still need development
未熟 describes an immature or insufficiently developed state. 「技術がまだ未熟なので基本から練習している。」 says the speaker is practicing from the basics because their skills are still immature.
技術 is the target here. まだ preserves the current lack of sufficient development, and なので connects it to practicing from the basics. This does not mean the speaker has no skills at all.
Unripe fruit left on a branch
「未熟な果実は収穫せず枝に残した。」 says the unripe fruit was left on the branch rather than harvested. 未熟な modifies 果実, the fruit, rather than a person’s ability.
収穫せず states that the fruit was not harvested, while 枝に残した states that it was left on the branch. Being unripe does not establish that the fruit was defective or discarded.
Let the target guide the interpretation
With 技術, 未熟 concerns the development of a skill; with 果実, it concerns ripeness. Do not turn both uses into an assessment of a person’s age, ability, or character.
The first sentence gives a reason for ongoing practice. The second gives a state and the completed action of leaving the fruit unharvested. Neither guarantees the later success of the practice or the ripening of the fruit.
In 「未熟な果実は収穫せず枝に残した。」, does 未熟な modify a person’s skill or the fruit?
Show the answer and why
It modifies 果実, the fruit. The sentence says the unripe fruit was not harvested and was left on the branch. It adds neither a judgment of personal skill nor a finding that the fruit is defective.