FACTORS AFFECTING HARDINESS IN FRUITS. 



PKOFESSOR U. P. HEDRICK, HORTICULTURIST, NEW YORK STATE 

 EXPERIMENT STATION, GENEVA, NEW YORK. 



The chief hindrances to fruit growing in North America are 

 winter freezes and spring frosts. No part of the Continent 

 where fruits are grown, excepting favored portions of Cali- 

 fornia, is free from the danger of a freeze that will kill the 

 trees, or a spring frost that will destroy the blossoms. The 

 losses suffered during the winter and spring of 1917 and 1918 

 threaten the existence of some fruits in many parts of the 

 United States and Canada. One of the problems which 

 growers of fruit now face is how best to avoid or check injury 

 from freezes and frosts. 



The problem is not an insurmountable one, for one finds 

 here and there varieties of orchards almost or wholly unin- 

 jured, and possibly adjoining others with trees or buds partly 

 or wholly killed. What conditiotis of the trees, of the soil, 

 or of the care make the difference? There must be reasons 

 for the injury of the one and not of the other. If we could 

 intelligently explain the eccentricities and anomalies of winter- 

 killing and spring frosts we might do something to avoid 

 injuries from unseasonable weather. 



The writer has made two efforts to find some explanation 

 of the varying behavior of peach trees during freezes and 

 frosts. In the spring of 1905 he addressed letters to about 

 100 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. The 

 great importance of the subject seems to have been obvious 

 to the peach growers, for almost without exception answers 

 were given by those addressed, and in such manner as to show 



