- 8 



It should be clear, then , that cold injury is the result 

 of a combination of environmental and physiological factors. Work 

 is now under way in Georgia to find an economical way to protect 

 the trees from this injury. It has been found that wrapping trunks 

 with aluminum foil backed with fiberglass is effective protection 

 but it is not economical. 



The type of injury that occurs in Georgia may be quite rare 

 or even unknown in New England. It certainly is not the problem 

 here that it is in Georgia. Nevertheless, the findings of Dr. 

 Savage's group should help us to understand why trees respond to 

 their environment in the way that they do. 



Do these results obtained in Georgia have any application to 

 us in New England? They do indeed! Eggert reported from New Hamp- 

 shire some years ago ( Proc. Amer. Soc. Hort. Sci . 45:33-36) that 

 between December, 1943, and March, 1944, peach tree trunks reached 

 60°F. or higher on 18 different days, and reached 80° or higher on 

 5 different days. On most of these days, air temperature was at 

 or below 32°F. He found that trunks of apple trees, on the other 

 hand, underwent far less severe temperature fluctuations, and this 

 difference he attributed to differences in smoothness, thickness, 

 color, and texture of bark. 



How much can be done practically to reduce cold injury to trees 

 is highly debatable. Nevertheless, the findings of Dr. Savage's 

 group should help us to understand why trees respond to their en- 

 vironment in the way that they do, and should help us to evaluate 

 problems that may develop. 



*************** 



IMPROVE YOUNG ORCHARDS WITH LIMB SPREADERS 



Duane W. Greene 

 Department of Plant and Soil Sciences 



The shape of an apple tree may be improved by favorably posi- 

 tioning limbs around the tree. At the 13th Annual Meeting of the 

 Dwarf Fruit Tree Association, Dr. Don Heintcke of the U.S.D.A, 

 Wenatchee, Washington, demonstrated a tree training system now used 

 extensively in the State of Washington. This system is based on 

 the use of a new commercially produced limb spreader. Briefly, 

 these spreaders are made of lengths of 1 x 1 inch wood ranging be- 

 tween 10 and 20 inches in length. A nail is inserted in each end 

 to securely keep the spreader in the tree. 



Not only are crotch angles improved but branches can be posi- 

 tioned to distribute vigor and improve light penetration. The im- 



