Sugar Prunes and Standard Prunes Compared
This picture shows the Sugar Prune at the left, and the Standard at the right, after drying. These prunes are very large, and have many qualities to commend them. The Standard prune is slightly less sweet than the Sugar prune, but its important quality of freestone is greatly in its favor. All in all Mr. Burbank regards the Standard as the very best drying and shipping prune that has yet been produced.
This image is from: Luther Burbank: his methods and discoveries and their practical application. Volume 5 Chapter 4