12 SUMMER APPLES IN THE MIDDLE ATLANTIC STATES. 



doubtless the most potent of any in their effects upon plant growth. 

 It is not intended, however, within the limits of this paper to discuss 

 at length what these effects are, even if it were possible to do so. 

 There is an unfortunate lack of adequate means for measuring some 

 of these elements, which doubtless are of great importance, and of 

 interpreting them in terms of their influence upon plant life. Records 

 of precipitation and temperature are abundant, but they seldom 

 represent actual orchard conditions, being taken usually at points 

 more or less distant from fruit plantations and often with instruments 

 attached to buildings many feet above the surface of the ground. 

 This is true, at least, of many of the records which are continuous 

 for any considerable period of time. 



In general it may be stated that in order for a plant or a variety to 

 succeed without irrigation there must be sufficient precipitation to 

 maintain growth adequate to the end for which the plant is intended. 

 As regards temperature, the extremes must be within certain more or 

 less definite limits, and the mean, especially for the more critical 

 periods in the fife of the plant, must accord with the particular 

 requirements of each individual. The mere matter of late spring 

 frosts — an unfavorable extreme at a critical period — may indicate the 

 impossibility of successfully growing certain fruits in some locafities. 

 As applied to the region now being considered, it is sufficient to state 

 that with certain general exceptions, noted elsewhere, the climatic 

 conditions are favorable for the cultivation of early apples in most 

 sections of the region. The orchards now in bearing testify to this 

 fact. The extremes of temperature in most parts of the region are 

 not severe, the precipitation is usually sufficient to meet the rec(uire- 

 ments, and the other climatic factors in most sections are equally 

 favorable to the end in view. 



The following tables, taken from the Monthly Weather Review for 

 the years 1902 to 1907, inclusive, are composed of clmiatological 

 records at three different stations located respectively in the southern, 

 central, and northern sections of tliis region. They represent to some 

 extent the climatic conditions wliich prevailed during the years men- 

 tioned and furnish one of the best available means for comparing the 

 cfimate of tliis region with that of other sections where smiilar data 

 are to be had. Such a comparison should assist in correctly fore- 

 casting for other sections the behavior of the varieties considered, so 

 far as the climatic factors are concerned. These climatological data 

 are also inserted for use in connection mth the phenological records 

 that appear on later pages. 



As will be noted, the following table gives the monthly maximum, 

 minimum, and mean temperatures and the precipitation. The 

 geographical arrangement of the stations as they appear in the tables 

 is from south to north. 

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