THE CLIMATE. 



23 



uriant growth of the rainy tropics prevails. With a minimum of 

 heat and moisture in the form of ice and snow, moss and other plants 

 of a relatively low order prevail, as in the Arctic region. 



The rainfall of a place is influenced largely by the configuration 

 of the earth's surface, the direction and height of mountain ranges, 

 and the direction of the prevailing winds. The temperature is gov- 

 erned mainly by latitude, elevation, and proximity to large bodies 

 of water, especially if these are very deep. However, the necessary 

 combinations of temperature and moisture to produce a maximum 

 plant growth or crop of fruit seldom, if ever, exist. The combina- 

 tion which would produce the greatest vegetative growth might not 

 be the most desirable for fruit production. 



Slight difl^erences in climate, especially in temperature and mois- 

 ture, often make great difl^erences in the development of plant life. 

 In this connection, however, it should be noted that a high tempera- 

 ture for a relatively short period often hastens maturity more than 

 a higher mean temperature which does not reach the requisite extreme 

 for a short period. In other words, within the climatic range of a 

 plant the mean temperature is of less relative importance than a suit- 

 able range of temperature during the critical periods of the plant's life. 



Comparatively slight differences in moisture are equally conspicu- 

 ous, as wLen a ''timely rain" insures the perfect development of some 

 crop and in the absence of such a rain a light harvest is the result. 



While such readily apparent results may obtain only with those 

 crops which complete their growth in a short period, they at the same 

 time emphasize the fact that climate has much to do with the devel- 

 opment of plant growth. And what is true in principle in its relation 

 to plants which mature in a short period of time is also true in prin- 

 ciple in its relation to plants, such as orchard trees, which require a 

 long period to fulfill their purpose. This is especially noticeable in 

 the relative times at which the annually recurring epochs, such as 

 blossoming, putting forth of the leaves, ripening of the fruit, etc., 

 take place from year to year. 



There is an unfortunate lack of data relative to climatic conditions 

 which actually exist in orchards. Nearly all the available climato- 

 logical records have been made at stations located in towns or at points 

 more or less distant from orchard sites; hence, the best available 

 records frequently do not accurately represent the climatic conditions 

 which have prevailed in orchards, even in the sections where the 

 records have been taken. Such records, however, are not without value 

 for the present purpose, inasmuch as they furnish a means of compari- 

 son, in a general way, of different fruit-growing sections. Tables I, 

 II, III, and IV, giving a monthly summary of the maximum, mini- 

 mum, and mean temperatures and amount of precipitation, are taken 

 from the Monthly Weather Review issued by the Weather Bureau 



135 



