The pomological researches are mainly focused on the development of and the cultural techniques and physiological studies in fruit trees. The goals of fruit tree improvement include enhancement of fruit quality, regulation of production periods, and reduction of production cost.
Pomology has been an important area of research since the early years of the United States Department of Agriculture (USDA). During the mid-1800s, farmers were expanding fruit orchard programs in response to growing markets. At the same time, horticulturists from the USDA and agricultural colleges were bringing new varieties to the United States from foreign expeditions, and developing experimental tracts for these fruits. In response to this increased interest and activity, USDA established the Division of Pomology in 1886 and named Henry E. Van Deman as chief pomologist. An important focus of the division was to publish illustrated accounts of new varieties and to disseminate research findings to fruit growers and breeders through special publications and annual reports.
The introduction of new varieties required exact representations of the fruit so that plant breeders could accurately document and disseminate their research results. Since the use of scientific photography was not widespread in the late 19th Century, USDA commissioned artists to create watercolor illustrations of newly introduced cultivars. Many of the watercolors were used for lithographic reproductions in USDA publications, such as the Report of the Pomologist and the Yearbook of Agriculture.
Today, the collection of approximately 7,700 watercolors is preserved in National Agricultural Library's Special Collections, where it serves as a major historic and botanic resource to a variety of researchers, including horticulturists, historians, artists, and publishers.