318 Peach-Growing 



under which injury was caused and why it occurred in some 

 orchards or in parts of orchards and not in others. 



The summary of conditions incident to the freeze in ques- 

 tion made by these authors is illuminating : 



" General cause of the 'finish ' of vast areas of peach 

 orchards in the Lake Erie fruit belt : the severe and pro- 

 longed cold of the winter of 1903-1904. 



"General cause of unusual susceptibility to cold, of the 

 orchards of said district : prevailing low vitality of the trees. 



" Specific causes of low vitality of the trees : San Jose 

 scale, leaf-curl, lack of nourishing plant-food, imperfect 

 drainage. 



" Exceptional causes of susceptibility to cold in rare cases 

 of apparently healthy, vigorous trees : low, moist, rich black 

 soil which favored an extreme growth of soft, poorly ripened 

 or matured wood; or high culture upon soil rich in plant- 

 food w^hich brought about similar results. 



"The unusually deep, hard freezing of the earth's crust 

 was due, directly, to the continued, steady cold, but was 

 intensified, in many instances, by a lack of humus or vege- 

 table matter in the soil, which constitutes nature's insulation 

 of the surface of the earth from cold and heat. 



" Providing that the orchards had been kept free from fun- 

 gous disease and the San Jose scale, by timely and thorough 

 spraying, no injury of trees was found where stable or barn- 

 yard manure had been used upon the ground within the last 

 year or two previous to the winter of 1903-1904 ; rarely was 

 an injured tree found standing in sod ; no injury was done 

 where the surface of the soil, beneath the trees, had been 

 covered with even a very light mulch ; little injury was done 

 where the trees stood in fairly well drained soil containing 

 a moderate amount of fertility and humus; no injury was 



