Which agricultural discipline focuses on the propagation and cultivation of crops?

The correct choice is agronomy because it is the agricultural discipline that specifically deals with the science and practice of crop production and soil management. Agronomists study various factors that influence crop growth, including soil fertility, water management, pest management, and crop rotation. They work towards maximizing the efficiency and sustainability of crop production, focusing on broad-scale agricultural practices that impact food supply.

Other options represent more specialized areas within agriculture. Silviculture is primarily concerned with the growth and management of forest trees, while plant breeding focuses specifically on the genetic improvement of plant species for better yield, disease resistance, or other desired traits. Horticulture, on the other hand, concentrates on the cultivation of garden crops, fruits, vegetables, and ornamental plants, which may involve smaller-scale production techniques compared to the broad applications seen in agronomy.