WOUND DRESSINGS ON APPLE TREES 



9 



tendency prevailed at the end of the second year (fig. 3, B) where 

 all the treatments, except the shellac, showed less killing in the 

 spring than in the winter. However, rapidity of healing in the 

 transverse diameter was not so consistently correlated with the season 

 of wounding:. 



Figure 3. — Comparison of average changes in longitudinal and transverse 

 diameters of wounds made in the winter months (November, December, and 

 January) and in those made in the spring months (February, March, and 

 April): A, At end of first season; and B, at end of second season. The 

 lines represent the original wound size (25 millimeters). Figures above 

 indicate wound extension by dying of tissue, and those below indicate de- 

 crease in wound size by healing. 



The data given in figure 1 for the condition of wounds at the end 

 of the first growing season indicate that those wounds made before 

 May showed more healing than killing in the transverse diameter. 

 The wounds made in May and subsequently and treated with dressing 

 No. 540 showed on the average more enlarging than healing. At the 

 time of the June wounding and treating there was very slight closing 

 of the wound by callus in the check and shellac treatments, whereas 

 in all the other treatments the enlargement by killing was appreciable. 



462609' 



-42- 



