Answer:
They symbolize masculanity.
Step-by-step explanation:
The book, "Thing Fall Apart," centers around the Igbo people. In their village they value agriculture greatly. In the text, it is stated,
"His mother and sisters worked hard enough, but they grew women’s crops, like coco-yams, beans, and cassava Yam, the king of the crops, was a man’s crop."
The smaller crops represent the women, as they are not as valuable. The Yams on the other hand are highly valued, and are described as a man's crop.