Which of the following is not a branch of agriculture?

Horticulture, forestry, and agronomy are all branches of agriculture because they involve the cultivation and management of plants and natural resources for human use.

However, zoology is not a branch of agriculture. Zoology is the study of animals, their behavior, and their interactions with their environment. While animals play a significant role in agriculture, such as livestock farming, animal husbandry, and animal breeding, these activities are considered under animal science or animal husbandry, which falls within the larger field of agriculture.

In summary, zoology is not a branch of agriculture because it focuses primarily on the study of animals and their behaviors, while agriculture encompasses the cultivation of plants and management of natural resources for human use.