22 BULLETIN 974, U. S. DEPARTMENT OF AGRICULTURE. 
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cially adapted to the management of wild uncultivated areas of the 
two common lowbush species of the northern ‘United States, Vae- 
cintum angustifolium and V.canadense. Since the highbush blue- 
berry, Vaccinium corymbosum, however, requires drastic pruning 
only at intervals of many years, and even then at different times for 
different bushes, burning is not a good method for pruning this 
species. This is especially true of cultivated plantations, where 
competing vegetation is kept down by other means. 
YIELD. 
By proper manipulation in the greenhouse, seedling blueberry plants 
can often be made to ripen a few berries when they are 1 year old, 
but they do not come into commercial bearing in field plantations 
until they are about 4 years old (Pls. XXV to X XIX), when the 
plants are 1 to 3 feet high. They then increase slowly to full size 
and full bearing. Wild bushes of the swamp blueberry live to great 
age, often 50 to 100 years, still bearing heavily, and they often attain 
a height of 6 to 8 feet when growing in full sunlight; still more 
when shaded. Individual stems may remain productive from 10 to ~ 
25 years. When dead they are replaced by new and vigorous shoots 
from the root. 
The great promise of blueberry growing as an agricultural in- 
dustry, in just the right soil and under good business management, is 
indicated by the yields from the oldest of the hybrid plantings at 
Whitesbog. This planting consists of about a third of an acre, the 
plants 7 years old in 1919. They yielded in that year at the rate of 
96 bushels per acre. The berries sold at a little over $10 a bushel, in 
addition to express charges and commissions, the receipts being at the 
rate of $966 per acre. In 1920 this planting yielded at the rate of 117 
bushels per acre, with receipts at the rate of $1280 per acre. These 
plants were set at 3 by 5 feet and consequently yielded about twice 
as much per acre at this age as they would if they had been spaced 
as now advocated, at 4 by 8 feet. 
The yields from this planting, from the beginning, are shown in 
Table I. 
TABLE 1.—Yield and receipts from a planting of hybrid blueberries at Whites- 
bog, N. J., 1915 to 1920, inetusive. 
Com- aateaee | _ Com- Approxi- 
| Valve of F 
uted mate | "arf | puted } 
Year. yield per | price per | “TP. s = Year. | yieid per | price per ha ne 
acre. quart. al |; acre. | Quart. 
| 
Buskels.| Cents. | Bushels.| Cenis. 
[Cy Bie 2 line an ee Na i 6.6 18 | 27 al) AR 6 am tae ae diy a 46.9 | 30 $is9 
eee RR OS ME. 29.7 2 mS Hf S19! BME 95.8 | 32 966 
1917 58. 3 24 S| | i et 117.3 | 34 1,280 
@ Yield reduced by late spring frosts. 
