SELECTION OF FARM 



The average temperature during the 

 growing season is, of course, of more impor- 

 tance from the standpoint of crop produc- 

 tion than the average annual temperature. 

 Maximum and minimum temperatures or 

 the range of temperature must be consid- 

 ered as well as the average temperature. 



One of the most practical questions to 

 determine is the average date of the last 

 killing frost in the spring and the date of the 

 first killing frost in the autumn; in other 

 words, the length of the growing season. 

 Both altitude and topography enter into this 

 problem. In a given locality killing frosts 

 will occur on a still night in the valley be- 

 fore they do on the elevations, because the 

 air as it cools becomes heavier and flows 

 down into the lowest places just as water 

 would do. On the other hand, as the alti- 

 tude increases the growing season shortens. 



Whenever I am asked a question involv- 

 ing the production of farm crops by a 

 Pennsylvania farmer before answering, I 

 ask three questions: (i) Where are you 

 located? (2) Do chestnut trees grow natu- 



79 



