The foliage of the central tree indicates a vegetable and digestive system in first class condition. Such a tree, with its large, abundant foliage, may safely be selected for the production of a fine quality of fruit. As we have already seen, this selection may be made when the seedling is still a small plant; the future tree will almost surely live up to expectations, based on its foliage.
This image is from: Luther Burbank: his methods and discoveries and their practical application. Volume 5 Chapter 6