40 BULLETIN 500, U. S. DEPARTMENT OP AGRICULTURE. 



Iii arriving at these averages the same weight is given each age, 

 regardless of the number of estimates, thus avoiding weighted aver- 

 ages. In getting a yield for the three counties, however, an average 

 is figured on the basis of the 125 records as though there were no 

 division in counties, thus giving each record its proper weight in the 

 grand average of all records. 



On the farms studied it was found that the average yield for all 

 apple orchards between the ages of 13 and 18 years was 284 boxes 

 per acre, or 3.8 boxes per tree. The uniformity of the yield in the 

 three different counties shows that these figures present a fairly 

 accurate average. The yield is only for packed boxes of market- 

 able fruit. To express the yield in terms of loose boxes, one-half must 

 be added to this average. Packing-house managers and growers 

 agree that on an average three loose boxes pack out two packed 

 boxes. 



If the average yield for each individual record is taken regardless 

 of age of trees, the average of all orchards is 278 boxes per acre. 



.In order to determine the influence of the size of orchard on yield, 

 104 individual records of fairly uniform ages were used. Of these, 35 

 were over 10 acres in size., 47 were between 6 and 10 acres, inclusive 

 and 22 were 5 acres and under. 



Table XXXIII. — Relation of size of orchard to yield. 



Size orchard. 



Number of 



orchards. 



Yield 

 per acre 

 (boxes). 



Over 10 acres 



35 

 47 

 22 



230 



6 to 10 acres, inclusive 



285 





316 







It is apparent from Table XXXIII that size of orchard has a direct 

 bearing on the yield per acre. The number of trees per acre remained 

 practically constant. The large yields per acre on the small orchards 

 may be accounted for, in part, by the better care which they receive, 

 since a grower naturally can attend to more details with a five-acre 

 orchard than with one of twenty. 



The different systems of orchard management as regards the use of 

 mulch crops and clean cultivation made no appreciable difference hi the 

 yields. However, a comparison by this method would not be fair in 

 this connection, since mulch crops have not been in use long enough 

 to affect the average yield when these records were taken. It may 

 be said that the use of mulch crops apparently has not decreased the 

 yield, while continued intensive clean cultivation with no addition of 

 humus has decreased it. Orchards regularly manured showed a yield 



