Nut Crops of the Midwest

Northern pecan [Carya illinoensis (Wangenh.) K. Koch] and eastern black walnut (Juglans nigra L.) are two important native nuts grown and sold commercially in the Midwest region of the United States. While other less common native nuts are found in local markets, their small kernel size and thick shells prevent their widespread acceptance.  Native northern pecan trees are often found growing in a floodplain or near streams and rivers.  Northern cultivars differ from southern types in that the nut and kernel size is smaller, kernel oil content is greater, shells may be thicker, and nut yields are lower.  Native eastern black walnut trees are adapted to deep, well drained soils. Although 99% of the black walnuts marketed are from native trees, several cultivars have been recently fingerprinted.  While nuts from wild trees generally have 17% kernel, those from cultivars are typically > 30%, with thinner shells and have improved cracking qualities. Although Chinese chestnut (Castanea mollissima Bl.) is an exotic species, it has potential for commercial production due to its resistance to chestnut blight and tolerance to low winter temperatures.  At the University of Missouri Horticulture and Agroforestry Research Center 110 northern pecan, 65 black walnut, and 65 Chinese chestnut cultivars are growing in repositories for evaluation of tree growth, nut production and kernel quality.  Breeding advances, as well as progress regarding sensory characteristics of kernels, floral biology, and tree propagation and management practices have been made within the past five years.