522 
Journal o f Agricultural Research 
Vol. XXVIII, No. 6 
PROGENY TESTS OF BUD VARIATIONS 
The individual-tree performance-record studies of many trees possessing 
marked limb variations which have been described in earlier reports suggest the 
probability that the established trees of diverse strains occurring in the per¬ 
formance-record plats and similar ones observed in commercial orchards were 
unintentionally propagated from limb variations. 
In order to secure definite evidence upon the perpetuation of diverse strains 
with especial reference to quality of fruit, experimental propagations were begun 
in 1915 using bud wood secured from limb variations which resembled in fruit 
and foliage characteristics some of the trees of several of the strains under in¬ 
vestigation. These propagations were made on selected sour orange seedlings in 
a commercial nursery in cooperation with the Citrus Experiment Statfbn of the 
University of California and some of the resulting progenies were planted on the 
grounds of the Citrus Experiment Station at Riverside, Calif., in July, 1917. 
The land on which these progeny plantings are located had previously been 
planted only to winter grain crops which had been grown without irrigation or 
fertilization. Little or no fertilizer has been used in this experimental progeny 
orchard other than that secured from the legume cover crop growth which has 
been plowed under once or twice each year and no pruning of the trees has been 
done thus far. 
Each progeny was planted so that the trees stand 10 feet apart in the same 
row, this close planting providing for many more trees in the available area than 
could otherwise have been grown. The usual cultivation and irrigation methods 
have been practiced and orchard heaters have been provided for frost protection 
during periods of low temperatures. The performance record of each tree has 
been secured every year since they came into bearing, particular attention being 
given to recording the number and quality of variants from the normal type of 
fruit. 
BROWN-SPOTTED AND EARLY RIPENING LIMB VARIATIONS 
The parent tree in which the first limb variation of this type was discovered 
is a tree of the Thomson strain of the Washington Navel orange variety on the 
Victoria ranch of the National Orange Co., at Riverside, Calif., which came to 
the attention of the senior writers in 1915 when it was 12 years old. The root- 
stock used in the propagation of the parent tree was sweet seedling orange. 
The size of the tree and the appearance of the foliage indicated a normal and 
healthy condition of growth. 
The fruits borne by the parent tree are quite variable, the majority being 
classed as typical of the Thomson strain while some of them very closely resem¬ 
ble typical fruits of the Washington strain. The Thomson fruits are distin¬ 
guished by very smooth and comparatively thin rinds having a bright reddish- 
orange color. The flesh is coarse and the fruits usually lack juice to such a 
degree as to render them very much less desirable than are those of the Wash¬ 
ington strain. The fruits of the Washington strain have somewhat coarser and 
thicker orange-colored rinds but have very tender flesh with an abundance of 
juice, making them very desirable. 
One limb of this parent tree produces very early ripening fruits of small size, 
distinctly flattened, pale yellow in color with occasional reddish stripes and 
marked with sunken brown spots of irregular shapes and sizes. The spotted 
oranges usually have only a small or rudimentary navel and frequently the 
navel opening is entirely closed. The rinds of the fruits are usually very thick 
and the flesh coarse and tough. The fruits ordinarily have but little juice which 
is normally lacking in both acid and sugar, making them very undesirable. The 
fruits mature and most of them drop from the tree during November and De- 
