I recommended a book entitled "World Vegetables: Principles, production, and nutritive values (Rubatzky and Yamaguchi, 1997) as a teaching material especially for vegetable crops. This book explains comprehensively regarding crop description, utilization, and production.
There are number of books available for different disciplines of Hort. Materials are also available sufficiently online. However, as per the prescribed course content, credit load and understanding level of undergraduate students Instructor should decide what to teach and what to not.
I meant that at the syllabus of faculty we have a subject titled ”fundamentals of horticulture, ” and of course it is general information on Horticulture, including pomology, horticulture, ornamental plants, general physiology, general BOTANY etc.
I would specifically suggest basic of horticulture by Jitendra sing and Glastus horticulture by P. Muthukumar and R. Selvakumar. These are two books which I used to understand the basis and concept during my bachelor in India. Hope you will find it helpfull.