This collection includes the diary, record book, and photographs of botanist and agronomist Wilson Popenoe, who studied avocados, navel oranges, mangoes, and other plant life throughout Mexico, Central and South America. Popenoe was employed by the United States Department of Agriculture Office of Seed and Plant Introduction in the role of agricultural explorer from 1913-1925, where he collaborated with David Fairchild, Archibald Shamel, and Palemon Howard Dorsett.