14 



on each tree, although on individual trees in some orchards 

 we have seen 50 per cent, of the apples diseased, and in many 

 cases no spotting at all was seen. The trees vv^hich were so 

 badly affected were old ones which had recently been culti- 

 vated and fertilized, and the manager attributed the out- 

 break to the application of nitrogenous fertilizers and the 

 recent renovation of the orchard. Another successful orchard 

 manager gave damp periods following drought as the cause. 

 For five years we have been having severe droughts in the 

 summer, followed by rains in the fall, and this spot has made 

 its appearance during this period. 



Winterkilling. 



Winterkilling often occurs below the surface of the ground 

 as well as above. During the cold winter of 1903-04 many 

 apple trees were seriously injured, both above and below, in 

 some States whole orchards being wiped out. Such injury is 

 not always associated with cold weather, much depending on 

 the condition of the tissue befol-e the tree enters the winter. 



The causes underlying winter injury are severe cold, when 

 the frost penetrates to great depths; sudden and severe cold 

 following prolonged warm periods in the fall; general low 

 vitality, caused by lack of food; insect or fungous attacks; 

 lack of moisture and organic matter in the soil ; lack of snow 

 covering; location in exposed situations, etc. Any condition 

 which favors a soft growth and immaturity of the wood, 

 whether from too much moisture or too heavy manuring and 

 fertilizing, tends to produce winterkilling, as does also 

 absence of sufficient sunlight. Trees gTowing where they re- 

 ceive the overflow from cesspools, etc., have been known to 

 winterkill when others near by would not. Piling dirt three 

 or four inches high around the base of young trees in winter 

 often causes injury similar to winterkilling in nature, and 

 tarred paper has the same effect. 



Barnyard manure used as a mulching helps to prevent 

 injury from winterkilling, and even sod is a great pro- 

 tection. 



