386 AGRICUI.TURE OF MAINE. 



following the winter injury of 1906-07 have convinced the 

 writers that as much if not more damage has occurred indirectly 

 from the attacks of fungi following the winter injury and which 

 gained entrance through the wounds thus made than as a direct 

 result of the winter injury itself. In many cases very little was 

 done to remove the injured parts and they were allowed to 

 decay and serve as breeding places for wood destroying fungi. 

 Later this decay followed back along the injured limbs or into 

 the interior of the trunks, resulting in the death of the entire 

 tree. 



While severe pruning and cutting back immediately follow- 

 ing winter injury is not advocated, all dead wood should be 

 cut out as fast as seen and the wounds at once covered with a 

 good liquid grafting wax or two or more coats of pure white 

 lead in boiled hnseed oil, and then repainted as frequently as 

 necessary to keep the wounds well coated till they are covered 

 with the new growth.* The dead bark on trunk and crotch in- 

 jured areas should be removed back to healthy tissue and the 

 wood thus exposed kept well covered with grafting wax or pure 

 v>'hite lead and boiled linseed oil. Bridge grafting may be used 

 where collar freezing occurs. 



Crotch injury. Associated with the winter-killing of 1906-07 

 many of the injured trees showed the bark killed in the crotches 

 as illustrated in Fig. 57. • A similar trouble was observed in 

 Ontario and other parts of Canada. There is some difference 

 of opinion as to just how this crotch injury \vas produced, but 

 there is no reason for regarding it other than as one form of 

 winter injury. This should not be confused with a similar 

 trouble caused by the pear blight bacillus which has been de- 

 scribed by Whetzel in New York. 



Frost bands on fruit. Occasionally late frosts occur which 

 are not sufficient to destroy the young fruit, but do result in a 

 peculiar characteristic russeting. As the apple enlarges and 

 approaches maturity this appears in the form of a band of vary- 



*In some instances severe injury to the trees has been reported 

 where the entire trunks have been heavily coated with lead and oil, to 

 prevent insect attacks. This may be due, however, to the use of im- 

 pure lead and either unboiled oil or some substitute for linseed oil. In 

 the writers' experience, and so far as can be learned, the use of pure 

 white lead in boiled linseed oil has been universally successful in treating 

 wounds made in pruning. 



