New York AGRICULTURAL EXPERIMENT STATION. 293 
ness of the scion seemed not always indicative of a hardy 
stock. The least affected varieties arranged according to their 
decreasing hardiness are said to be Siberian crabs, native crabs, 
Hibernal types of Russian apples, varieties of western origin, 
such as Northwestern, Patten Greening and varieties like 
Wealthy, Duchess and Tetofsky. 
In localities of severest cold and least snow covering, the 
trees in neglected, weedy nurseries were least injured, though 
varietal hardiness, deep planting and the extent of the scion 
root-system seemed also decisive factors. Banking and heading 
back are advised for injured nursery stock to induce the de- 
velopment of scion roots. The commercial apple stocks are 
thought to be unsatisfactory; a hardy seedling stock should be 
secured. 
For orchards already planted, deep plowing in the spring 
followed by shallow cultivation till mid-summer, is advised, 
thus inducing early growth and the consequent early ripening 
of the wood as well as to conserve soil moisture. A good 
cover-crop, such as clover or vetch, is thought highly impor- 
tant to prevent frost-injury of the roots.—To prevent injury to 
trees to be planted, it is suggested to plant unusually deep, 
especially on well drained soils, not filling the holes com- 
pletely but allowing subsequent cultivation to fill them. The 
final conclusions are that a lack of a snow-covering and low 
temperature combined are the chief causes of root-rot in 
nursery and orchard trees and that most injury occurred on 
clean-cultivated dry knolls with northern exposure. Cover- 
crops and deep planting are thought of paramount importance. 
Aven Nelson® suggests that since winter-killing is more 
common in Wyoming than in other States having equally low 
temperature, desiccation is the principal cause. High, dry 
winds and low barometer are given as the causes of desicca- 
tion. Late irrigation and mulching with straw, leaves or 
manure are advised. 3 
* The winter-killing of trees and shrubs. Wyo. Agr]. Expt. Sta, Bul, 15. 
1893. 
