346 The Commercial Apple Industry 



Cold wet weather which prevents pollination is largely re- 

 sponsible for low yield in certain sections. The history 

 of the region should be carefully noted in this regard. 



Total crop failures. — The number of crop failures in 

 the last ten years in any locality should be carefully noted, 

 for it is reasonable to assume that a like number will 

 occur in the next ten years. This consideration is highly 

 important and will also serve to avoid the danger of draw- 

 ing too favorable conclusions from exceptional perform- 

 ances of orchards in any particular year. 



Relative freedoyn from, diseases and insect pests. — The 

 probability of scab or bitter-rot infection should be noted 

 or the presence of any destructive disease or insect which 

 may greatly cut down the crop even after the fruit has set 

 well. Bitter-rot sometimes injures crops in the Virginia 

 Piedmont district. Severe infestations of codlin-moth late 

 in the season often cut the crop in the dry or irrigated 

 western districts. Cedar-rust frequently does heavy dam- 

 age to the York Imperial crop of the Shenandoah Valley. 

 Apple-blotch often greatly injures the apple crop of the 

 Middle West, while the prevalence of apple-scab renders 

 the market quality of the apple crop of New York and 

 Michigan uncertain. Every region has certain troubles, 

 but it is well to be on the lookout for them and to note 

 the success with which they are being controlled. 



The likelihood of hail damage. — Such regions as the 

 Piedmont of Virginia and to a lesser degree the Shenan- 

 doah-Cumberland district of Virginia, West Virginia, 

 Maryland and Pennsylvania are often visited by hail. 

 The same is true of the higher altitudes of Colorado and 

 other regions where fruit is grown at considerable alti- 

 tudes. Hail damage seems to be more prevalent through- 



