CHAPTER X 

 THE RELATION OF CLIMATE TO POMOLOGY 



The relation of climate to horticulture and agriculture is 

 very intimate and is almost the ultimate determinant of 

 what shall be grown. The orchardist feels that he has 

 reached the frontier of his knowledge and ingenuity in at- 

 tempting to combat the elements and overcome their devas- 

 tating effects. Other factors, of course, determine where 

 and what crops can be grown, but climate becomes the ac- 

 tual determinant as the northern and southern limits for 

 special crops are reached. 



While the forester studies the climatic conditions best 

 adapted to certain types of tree growth and then does his 

 planting accordingly, the horticulturist must consider the 

 climatic peculiarities and causes of failure and then deter- 

 mine means of overcoming them. It is also true that insect 

 and disease pests are more abundant and more destructive 

 some seasons than others, owing to favorable weather con- 

 ditions, and the grower must accordingly modify his plans 

 to combat them successfully. 



188. Terms defined. — Climate has been defined as the 

 average condition of the atmosphere, while weather denotes 

 a single occurrence, or event, in the series of conditions that 

 make up climate. The climate of a place is, then, in a sense 

 its average weather. Phenology is the science of the rela- 

 tions between chmate and periodic biological phenomena, 

 such as the flowering, leafing, and fruiting of plants. 



The particular natural phenomena constituting climate 

 that are of special interest in this connection are, tem- 

 perature, rainfall, wind, sunlight, frost, hail, and humidity. 

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