Which of the following is grown as a summer annual crop in Oklahoma?

Summer annual crops are those that complete their lifecycle within a single growing season, typically planted in the spring and harvested in the late summer or early fall. Corn is a key example of a summer annual crop, as it is planted after the last frost in spring and grows rapidly during the warm months, making it well-suited for the climate in Oklahoma.

In contrast, alfalfa is a perennial forage crop that can be grown over multiple years rather than being singularly annual. Wheat, while an important crop in Oklahoma, is typically grown as a winter annual, meaning it is sown in the fall and harvested the following summer. Canola is also generally classified as a spring or winter annual, depending on the climate, but it does not fall into the summer annual category in the same way corn does. Therefore, corn is the correct answer as it aligns with both the seasonal growing pattern and the agronomic practices prevalent in Oklahoma.