Concept:
Different crops differ in their tolerance to boron concentration in soil or irrigation water. Some crops are sensitive, while some crops are more tolerant.
Step 1: Sensitive crops.
Lemon and blackberry are relatively sensitive to boron.
\[
A \text{ and } B \text{ are not tolerant}
\]
Step 2: Tolerant crops.
Cotton is relatively tolerant to boron. Asparagus is also considered boron tolerant.
\[
C \text{ and } D \text{ are tolerant}
\]
Thus, boron tolerant crops among the given options are:
\[
C \text{ and } D
\]
\[
\therefore \text{Correct Answer is (C)}
\]