is necessary to remove many of the 

 crooked limby trees. The products of 

 these trees are of no commercial val- 

 ue because of small size and poor 

 form. Thus it is necessary to find 

 cheap methods of thinning, if the 

 job is to be done economically. 



During the growing season bark 

 may be peeled from trees quite easi- 

 ly. With this fact in mind, a peeling 

 tool was designed for girdling stand- 

 ing trees. After experimentation it 

 was found that the bark could be 

 quickly peeled away from a portion 

 of a tree trunk leaving an area of 

 exposed wood averaging a foot or 

 so in height. 



One hundred limby crooked trees 

 in a twenty-two year old plantation 

 were girdled in this manner. It took 

 an hour to do the peeling. No brush- 

 ing out was necessary. The height of 

 peeling was about four feet from the 

 ground. * 



Fifty of the trees were treated on 

 the barked area with 2, 4-D and 2, 

 4, 5-T, mixed with fuel oil. The mix- 

 ture was applied with a force feed 

 oil can. This chemical is commonly 

 used to kill woody vegetation. The 

 other fifty had no further treatment. 



Results to date show that only 

 those trees with the heaviest crowns 

 among the chemically treated trees 

 are still alive. Where only peeling was 

 done, the smaller trees are dead, but 

 it will take longer than one year for 

 a complete kill. 



In another area a sample of 100 

 tamarack trees was selected and 

 girdled by peeling. No chemical was 

 used in this instance. 



The peeled wood surface has 

 checked considerably and as in the 

 case of pine, all of the smaller trees 

 are dead. The larger trees have pro- 

 duced little new growth and consid- 

 erable wilting is evident. 

 L. C. Swain 



Horticulture 



Conditions for Apple Root Growth 

 Are Improved Greatly by Hay Mulch 



Root studies on Mcintosh apple 

 trees grown for eight years in Paxton 

 soil under hay mulch, sawdust mulch, 

 and sod systems of culture, have 

 shown a great deal of variability. 

 Hay mulch produced a soil of dark 

 color and granular structure down to 

 the "C" horizon, thirty inches deep, 

 and a dense mat of feeding roots ex- 

 tended down to that depth. Practical- 

 ly all roots were confined to the 

 nmlched area and extended only 

 slightly beyond it. Where no fertil- 

 izer was used, the root patterns un- 

 der sawdust mulch and sod systems 

 of culture were similar. They were 

 greatly reduced in number compared 

 with those under hay mulch. Under 

 the conditions of this experiment, 

 sawdust mulch had no apparent ef- 



fect on the texture of the soil under 

 it. 



During a comparatively dry sum- 

 mer the soil under sawdust mulch 

 was near the wilting point for about 

 one month. This is probably due to 

 the fact that light summer rains 

 failed to penetrate the six inches of 

 sawdust. During that time, and in 

 this particular year (1950), soil one 

 foot deep under the sawdust mulch 

 was drier than that under either the 

 hay mulch or sod systems of culture. 

 Available moisture in unmulched soil 

 at three and twelve inches deep be- 

 yond the spread of the branches and 

 mulch was below the wilting point 

 for two months. Further experiments 

 are under way to determine the effect 

 of mulching trees beyond the spread 

 of the branches. 



R. Eggert 



26 



