16 BULLETIN 614, U. S. DEPARTMENT OF AGRICULTURE. 
TABLE 1X.—Average yield per acre, 1910-1914, inclusive, for 120 orchards in Yakima 
Valley. 
E ; North Yakima and 
North ae dis- Zillah district. Zillah districts com- 
i | bined. 
Year. . | in 
| Average verage Average 
Nora ber yiel d in arb yi ield in Number yield in 
| packe packe z packed. 
records. | “boxes. records. Worcs records. ieee: 
113) (0 Yapeoetten ope Stakes iba ies ay 20 617.1 24 | 464.7 44 534.0 
1 (1g Ei ewan nes Wee pene Rew armani ke 2c : 30 | 277.9 33 216.8 63 246.0 
ght EARS ae earn speek SW Se a 2 51. | 617.3 48 | 591.3 99 604. 7 
1G Sere eee ee ee See ee eA 62 | 354. 6 54 | 328.6 116 342.5 
LOU Ae aS ee ae earn NAR TC a a nae 64 590.5 56 | 452.3 120 526.0 
There is a difference in the number of estimates considered in 
different years, yet the figures presented reflect the tendency to 
alternate bearing, as well. as the effects of weather conditions. 
The age of the trees has a marked bearing on the yield for these 
districts. Some varieties of apples in the Yakima Valley bear a few 
apples at the age of 5 years. However, in arriving at the average yield 
for the valley only the yields from orchards aged 7 years and over are 
considered. The majority of orchards from which records were taken 
were between the ages of 9 and 15 years at the time of this study. 
Each orchard is given the same weight and the acre is used as a basis 
of comparison. All yields were taken from orchards representitive 
of the district, so as to make the data comparable. There is a gradual 
increase in the yields of trees from the time they are 6 years of age. 
(See Table X.) 
- It will be noted that the yield per tree increases rapidly with the age 
until the tree reaches 9 years of age and that thenceforward the in- 
crease is more gradual. 
There were not enough records of intense over 12 years of age to 
furnish reliable figures. 
TABLE X.— Yield per acre from trees of different ages in the Yakima Valley. 
Yieldin | : 
Pe 
Number of estimates. ae i Decne’ PIES DEP BeaESe sh 
oxes. 
1 age Rat Sede «tote Wohi Se TN eR et eden opel visi By oe ae 8 da 6 175 75. 66 2.32 
Rte bie 8 ha Sg ga cee a ae ee a ere a 7 | 311 73. 50 4.23 
7 (ea agree nN hy on oon eM ay d ee BN A ere oth ce BE a 8 350 73. 82 4.74 
OS eek AS sees Ls Aiea ea 5 RR ee i eR 9 453 veewa! 6.14 
SS at os NS SRE eee a IE peoe ay Sen eee eet eee ee 10 454 74, 32 6.10 
15) Ue OIE iC ae eerie fom peek See Te Pye eee cn 11 469 foe 6. 51 
Sooo LI oe ee ee Re RON ARS An fete Re Snes eee 12 505 | 73.97 6. 83 
PASELAL GRE OTOL O be) le ae ee te tee en re ea nos oomesee eA 73.81 
The size of the orchard appears to have considerable influence on 
the yield throughout the districts. (See Table XI.) Small orchards 
have more trees per acre than the larger ones, and as a rule the ranch 
