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RECOMMENDATIONS. 7033 
Root grafts should be carefully fitted, especially with respect to the 
lower end of the scion, which should have a sharp end rather than a 
blunt one. The wrapping used should cover the union completely 
and should firmly hold the parts together until the graft is planted in 
the soil; then it should rot away when growth begins. 
In a large number of wrapping experiments cloth wrapping gave 
the best results. In a later experiment good results were obtained 
with a continuous-thread wrapping applied by a machine evenly and 
closely over all the union. 
Sand was found to be the best material tested for packing and stor- 
ing root grafts. Cold storage is best for root grafts that must be kept 
for some time before planting, since 1t prevents the overdevelopment 
of callus, a condition which favors the entrance of disease. 
RECOMMENDATIONS. 
The crown-gall and hairy-root of apple trees is primarily a nursery 
disease, gaining entrance most frequently the first year. In a well- 
regulated nursery it is desirable to grow and sell the best trees that 
can be obtained and at the same time not increase the cost of produc- 
tion. With this in view the following recommendations are made: 
(1) In order to keep the nursery as free as possible from the disease 
all diseased trees should be left in the field at the time of digging and 
burned as soon as dry. 
(2) The nurseryman should, as far as possible, get scions from 
healthy trees by growing them under careful selection or purchasing 
them from others who do this. Never plant diseased trees in the 
scion orchard. 
(3) Buy the best grades of healthy seedlings for budding and root 
grafting. Insist that growers of apple seedlings cull out and burn all 
diseased ones at the time of digging. 
(4) Make close-fitting root grafts, avoiding blunt ends of the root 
and scion in the union. Wrap with unwaxed cloth or continuous- 
thread wrapping, covering completely and firmly the wounded edges 
in the union. The root and scion should be approximately of the 
same diameter. 
(5) Store root grafts preferably in sand. If the period of planting 
is delayed beyond two weeks they should be placed in cold storage at 
a temperature a few degrees above the freezing point. 
(6) Plant the union of root grafts about 3 to 4 inches below the sur- 
face of the ground. Be careful not to break the callus in planting and 
avoid wounding the young plants in cultivation. 
(7) Propagate by budding, as far as possible, the few varieties 
most susceptible to crown-gall and hairy-root. Among these are the 
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