22 



BULLETIISr 974, U. S. DEPARTMENT OF AGEICULTUEE. 



cially adapted to the management of wild uncultivated areas of the 

 two common lowbush species of the northern United States, Vac- 

 cinium angustifolium and V. canadense. Since the highbush blue- 

 berry, Yaccinium corymbosuvi^ 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 clown 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 (Pis, XXV to XXIX), 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 

 A^'liitesbog. 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 $1,280 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 I. — -Yield and receijits from a planting of hybrid hlueherries at Whites- 

 hog, N. J., 1915 to 1920, inclusive. 



Year. 



Com- 

 puted 

 yield per 

 acre. 



Approxi- 

 mate 



price per 

 quart. 



Value of 



crop per 



acre. 



Year. 



Com- 

 puted 

 yield per 

 acre. 



Approxi- 

 mate 



price per 

 quart. 



Value of 



crop per 



acre. 



1915 



Bushels. 

 6.6 

 29.7 

 58.3 



Cents. 

 18 

 22 

 24 



$37 

 209 

 448 



1918 



Bushels. 



a 46. 9 



95.8 



117.3 



Cents. 

 30 

 32 

 34 



$449 



1916 



1919 



966 



1917. ... 



1920 



1,280 









a Yield reduced by late spring frosts. 



