12 SOME CONDITIONS INFLUENCING THE YIELD OF HOPS. 



the roots as soon as they are observed. In this way their perpetuation 

 may be prevented and the loss in yield due to their occurrence avoided. 



SUMMARY. 



A critical study of yield on an acre of hops in California selected 

 as representing the average condition of ()00 surrounding acres shows 

 that, owing to the occurrence of a large number of nonproductive and^ 

 missing hills, the actual yield was only 87.9 per cent of what might 

 be expected with a perfect stand. 



The yield from individual hills was found to vary from 0.5 to 18 

 pounds. Owing to the large number of low-yielding hills the average 

 yield per hill for the entire acre was reduced to 6.104+ pounds. 



The number of vines trained to each hill varied from one to eight. 

 As the number of vines per hill increased, the average yields of the 

 hills having the same number of vines were found to increase in 

 approximately the same ratio. 



Assuming a full stand of 957 hills with 6 vines trained to each hill, 

 the calculated possible yield is 65.2+ per cent greater than the actual 

 yield on this acre. 



" Bastard " or " mongrel " hills should be dug out and destroyed, 

 as they are of no value and diminish the total yield. 



Approved : 



James Wilson, 



Secretary of Agriculture. 



Washington, D. C, March 7, 1910. 



[Cir. 5G] 



