498 



ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 



previously weakened by disease or me- 

 chanical injury showed the most winter 

 killing. This was especially true in Fre- 

 mont, Pottawattamie. Mills, Iowa, Polk 

 and Page counties, south of the Rock Isl- 

 and railway, where no cases of injury 

 found was traceable to winter killing 

 alone. Here the blister canker or Illinois 

 canker was the most common cause of in- 

 jury and it is considered by the experi- 

 ment station as a very serious menace to 

 Iowa orchards. In a recent bulletin is- 

 sued by the station on new fungus 



Fig 1. rankt-r nii \<niiig lift'. 

 Winter Injury. 

 (Purdup Experiment Station. I 



growths in Iowa, No. 131, there is a de- 

 scription of this disease. In Harrison 

 and Woodbury counties, winter's severe 

 cold is the chief cause of trouble. 



Where orchards are afflicted with 

 canker or other disease, the diseased 

 wood should be cut out. That should be 

 done at once. The cuts should extend 

 back well into the healthy bark and wood. 

 The wounds should be thoroughly cleansed 

 and disinfected with any good disinfect- 

 ant, as formalin, corrosive sublimate, 

 copper sulphate, Bordeaux mixture, or 

 lime sulphur, and then covered with 

 paint. 



Where the trees have been weakened, 

 provide them with a generous and con- 

 tinuous supply of food and the soil moist- 

 ure necessary to make the food available 

 to the tree. This can be done by break- 

 ing up the land and keeping the soil well 

 tilled so as to form a dust mulch at least 

 three inches deep. Whenever possible, 

 apply manure, especially where the soil 

 is too steep for cultivation. This will 

 add fertility and helps to conserve moist- 

 ure. This treatment will bring many 

 trees back into good condition and, while 

 they may not produce apples this season, 

 its beneficial effects will continue for a 

 good many years later. 



S. A. Be.\ch, 



Ames, la. 

 Wounds 



No artificial medium can be applied to 

 the surface of a wound which will induce 

 it to heal more quickly. The activity of 

 the healing process depends upon the 

 character and position and the time of 

 year when the wound is made rather 

 than upon protective coverings. 



Large wounds which result from the 

 removal of branches of considerable diam- 

 eter, leaving a large surface of heartwood 

 exposed, may with advantage be protect- 

 ed by painting the cut surface with a 

 heavy coat of white lead, the sole object 

 of this precaution being to protect the 

 heartwood from decay until the new 

 growth, which forms from the growing 

 tissue immediately under the hark, has 

 had time to develop over the exposed 

 dead wood and protect it from decay. 



A large number of waxes, paints and 

 washes have been tried, and the con- 

 clusion of the whole matter may be sum- 

 marized in the statement that any sub- 

 stance which is not corrosive or detri- 

 mental to growth which will protect the 

 heartwood from the attacks of rot spores 

 will prove a satisfactory covering for a 

 cut surface. Among such substances may 

 be mentioned white lead, yellow ocher. 

 coal tar, and grafting wax. 



L. C. COBBETT, 

 TVashinKton, D. C. 



Yellow Leaf. See Rosette. 



