walnut have been reported.9 The exploration of various hybrids might well lead to valuable new types.
Other Developing Regions. Andean walnuts deserve to be included in forestry and agroforestry trials in areas of upland Central America and Brazil, the hill regions of India, Pakistan, and Nepal, and other seemingly suitable subtropical and tropical highland regions.
Edible nuts are rare in many parts of the tropics, and their commercial production is practically nonexistent. However, the Andean walnut may provide a new, multipurpose tree crop for the middle-elevation areas of the tropics and for the subtropics.
Industrialized Regions. Any walnut species that can reach 10 m tall in 10 years in a temperate area such as New Zealand deserves testing as a plantation crop. Worldwide demand for walnut timber outpaces current supplies, and outside the Andes this crop's potential is probably greater for timber than for nuts. Silvicultural trials should be initiated with this and other Juglans species in a search for the combination of fast growth and high-quality timber. Perhaps, also, robust hybrids can be created.
For example, hybridizing the tropical species with some of the best timber and nut selections from the temperate walnut (J. nigra) might produce trees for the tropics that produce both high-grade furniture wood and fine-quality nuts.