304 The Principles of Fruit-growing 



As to treatment, he remarks: "The killing of wood of 

 peach trees from freezing is one of the most important 

 determining factors in peach-growing. Little can be done 

 to influence the amount of killing except to have the trees 

 start into winter in proper condition of maturity. The 

 weakest-growing trees, however, do not generally reach 

 this condition of maturity in the most satisfactory manner. 

 Trees one or two years in the orchard, or old weak trees, 

 are most liable to succumb to effects of low temperature. 

 Pruning the trees severely following a winter when the 

 wood has been killed, although apparently in the best 

 condition of maturity, seems to reduce the amount of 

 killing. However, such pruning following winters when 

 the wood has been killed on account of its not having 

 reached the proper condition of maturity in the fall, 

 generally due to the presence of wet weather following a 

 drought the season before, is liable to result in greater 

 loss than if no pruning were done. 



"In the peach-growing district of south Missouri and 

 Arkansas, and probably other similar climates, the most 

 important factor influencing the loss of peaches from low 

 temperatures in winter is keeping the buds from starting 

 into growth during warm periods in winter. In that 

 section the best means of accomplishing this end is pro- 

 longing the growth of the trees in autumn, either by 

 heavy pruning or by fertilizing with nitrogen the spring 

 before. Some varieties of peaches have a much longer rest- 

 period than other varieties, and therefore are started into 

 growth more slowly by warm periods in winter." (Page 101.) 



Frost cankers. 



The effect of winter injury may appear in the form of 

 sunken dead patches that sometimes exude gum. On 



