Temperature and Rain 41 



Location with reference to weather. 



In the preceding chapter, the general influence of cold 

 and heat in determining the fruit-zones was discussed. 

 At that place, the subject was the average annual tempera- 

 ture. But within these various zones there are endless 

 minor variations in physiographical features that have 

 a direct influence in determining the areas of the incidental 

 frosts of late spring and early fall. Moreover, the exposure 

 to destructive winds is to be considered, and in some 

 regions the Uability to rains at blooming time, and to 

 drying winds when the fruit is maturing. While these 

 dangers are beyond the control of man, nevertheless they 

 may be avoided to some extent; and we are beginning 

 to construct charts and tables of average local weather 

 so that the grower may calculate his risks in advance. 

 Herein is one of the greatest services that the science of 

 meteorology can render the farmer. 



"The average daily range in temperature," as found by 

 Hedrick, is "an important constituent of blooming-time 

 weather. When the daily range is highest the danger to 

 blossoms is greatest. The most jeopardizing weather to the 

 fruit-crop, from the standpoint of temperature, consists 

 of warm, sunny days followed by still, cloudless, cold 

 nights. The danger is all the greater in such stresses of 

 weather because the heat of the day forces out the blos- 

 soms prematurely." 



Rain at blooming-time. — In his study of New York 

 conditions for the years 1881 to 1905, Hedrick concludes 

 that "Rain and the cold and wind that usually accompany 

 it at blossoming-time cause the loss of more fruit than any 

 other climatal agencies. The damage is done in several 

 ways. The most obvious injury is the washing of the 

 pollen from the anthers. The secretion on the stigmas also 



