Thought I might login some fruits as well :)
Having clear and descriptive labels is always recommended. So to answer your question directly: Yes you should ask as an input field with a more generic label invites ambiguity. Placing a clear label (in this case questions) above each control helps establish clear relationship between what you are asking for and the means by which it could be provided.
The second aspect you need to take into concideration is how the questions are formulated: If input fields can only accept apples and oranges (which I assume is the case) then the questions will need to reflect that, gain clarity and be focused on the task.
From your comment that suggests that your target audience had initially difficulties identifying what an input field is! Then, it honestly seems to me that this is an educational challenge and should be treated as one. So I would suggest the following to achieve best results:
- Language used: aligned with your users expectations and understanding.
- Emphasis:Bold text where relevant.
- Repetition: structure of question should be the same for apples and oranges.
- Illustration: via easily recognisable icons or images to reinforce labelling.
Form Narrative : Make the form tell a story!
Test and refine