Bui. 1477, U. S. Dept. of Agriculture 
Plate 39 
Response of Burton and Sweetheart Plum Trees to Pruning and 
to Soil and Other Conditions 
A. — An 8-year-old Burton tree growing in fertile but unirrigated soil. This tree has been 
moderately headed back and the branches lightly thinned out each winter. Thrifty 
spurs are found throughout the tree. (Vacaville, Calif., August, 1924) 
B.— An 18-year-old Sweetheart tree, photographed just after the 1-year shoots had been 
removed or headed back. Note the numerous and much-branched twiglike spurs along 
all branches. The tree is growing in fertile irrigated land. (Courtland, Calif., 1924) 
C— Six-year-old fruiting wood of a vigorous Sweetheart tree. (Compare with B) 
