Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 12/7/2017
Publication Date: 3/15/2019
Citation: Preece, J.E., Aradhya, M.K. 2019. Temperate nut crops – chestnut, hazelnut, pecan, pistachio, and walnut. Book Chapter. (2):417-449. https://doi.org/10.1007/978-3-319-97121-6_13.
DOI: https://doi.org/10.1007/978-3-319-97121-6_13 Interpretive Summary: Nut crops are grown for their high calorie, nutritious seeds that humans have consumed over millennia, beginning with the gathering of wild nuts. For some ancient peoples, these nuts served as meat substitutes especially is isolated areas, such as islands that had limited numbers of animals to use as protein. Today, nuts, their oils, flours, and other edible products are popular worldwide. In addition to their culinary uses, tannins from the bark can be important, dyes can be extracted, and the hard, finely grained wood has high value for woodworking and veneer, with some, such as chestnut having good rot resistance for fence posts and other uses requiring ground contact. Cultivation of these nut crops contributes greatly to local and national economies and they sell well because they are tasty and are an important part of a healthy diet. There are wild relatives of 5 major nut crops in North America. Pecan is the only endemic North American nut crop with a wide and important international market. The wild nut crops in North America are important sources of genes for improving their cultivated relatives, and may have primary uses other than food, such as their valuable wood. The most economically important species of chestnut, hazelnut, pistachio and walnut originate from Europe into Asia. Native peoples began collecting and eating these nut crops first by collecting from the wild and then through cultivation. The advent of successful and efficient grafting greatly increased the cultivation and importance of these crops because clonal selection of superior individuals was now possible. North American wild nut relatives are used for disease resistance of both the scion and rootstock portions of these nut trees. Conversely relatives from foreign nut crops are also used to impart disease resistance into North American endemic species, such as overcoming the susceptibility of American chestnut to chestnut blight.
Technical Abstract: Wild relatives of chestnut, hazelnut, pecan, pistachio, and walnut are endemic in North America. Pecan is the only major nut crop native to North America; however, the wild relatives are important sources of useful genes, especially disease resistance. Hazelnuts are curated by the National Clonal Germplasm Repository, Corvallis, OR; pecans by the National Collection of Genetic Resources for Pecans and Hickories, Somerville, TX, and pistachios and walnuts by the National Clonal Germplasm Repository, Davis, CA. History, uses, distribution, and vulnerability of each population are described.