The most common and most likely answer to this crossword clue is the 4 plus 6 letter word PLUM TOMATO
I've seen this crossword clue in The Sunday Telegraph
P
L
U
M
T
O
M
A
T
O
More clues leading to the result PLUM TOMATO
Buddy explains!

The straight part
We know that "Large fruit" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case large fruit = plum tomato.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.