Factors Affecting Hardiness of the Peach. 



BY U. P. HEDRICK, Geneva, N. Y. 



The peach affords a striking example of a plant undergoing 

 acclimatization. In the wild state, this species is endowed with 

 a constitution fitted to endure the heat of climates almost sub- 

 tropical. Under domestication it is gradually becoming inured 

 to climates far to the north of its habitat and so cold that at first 

 it could not have lived in them. It may be that this change 

 is somewhat due to the acclimation in which the plant is natur- 

 ally or spontaneously becoming habituated to cold ; but the peach 

 can now grow in colder climates than formerly, chiefly because 

 of the efforts of man to secure this change in the species. What 

 are the means by which man can aid in acclimatizing- a spe- 

 cies or a variety to a climate at first injurious to it? 



I have made two efforts to find some explanation of the 

 varying behavior of peach trees during freezes and frosts, work- 

 ing at the problem from the standpoint of the horticulturist, 

 and the information obtained in these investigations shows some 

 of the means by which man is helping to acclimatize the peach 

 and by which possibly other species might be acclimatized. In 

 the spring of 1905 I addressed letters to about one hundred of 

 the best peach growers in Michigan, asking for their experience 

 as to the hardiness of the peach in tree and bud. In the spring 

 of 1907 about the same number of letters were addressed to 

 peach growers in New York. This paper is a brief review of 

 the answers obtained. In making these investigations I have 

 visited the orchards of many of my correspondents, and have 

 noted the condition of the trees under consideration and have 

 a personal knowledge of many of the conditions discussed. 



The factors considered in the investigation fall under two 

 heads : 



I. Cultural treatment, which increases the ability of the in- 

 dividual trees to withstand cold. 



