18 



MISCELLANEOUS PAPERS. 



the resulting' trees when dug in the autumn showed fairly g'ood unions. 

 The grafts as a whole fell below the wrapped ones in the number of 

 smooth trees. There were more deficient trees in this lot, with the 

 possible exception of those waxed over, owing to defective unions and 

 failures to form a union. 



EFFECT ox CEOWX-GALL FORMATION. 



As indicated in the introduction, one of the objects of the experiment 

 was to determine whether by wrapping grafts it would be possible to 

 reduce the number of trees affected with crown-gall. In the f oUowingf 

 table the total number of trees dug is given; also the kind of wrapping, 

 and the number and percentage of smooth trees, crown-gall trees, and 

 hairy-root trees : 



Table II. — Comparison of smooth trees and trees affected with croivn-gall and hairy-root^ 

 resulting vjhen different methods of grafting were used. 



Kind of wrapping. 



Kubber 



Cloth 



Waxed paper 



Plain thread 



Waxed thread 



Plain thread with 



waxed 



Unwrapped 



Total 



Smooth trees. 



Crown-gait trees. 



Hairy-root trees. 



number. 



Number. 



Per cent. 



Number. 



Percent. 



Ntimber. 



Per cent. 



^ 675 



584 



86.5 



65 



9.6 



26 



3.9 



709 



604 



85.1 



70 



9.8 



35 



5.1 



671 



474 



70.6 



■ 168 



25.0 



29 



4.4 



645 



442 



68.5 



130 



20.2 



73 



11.3 



675 



430 63. 7 



182 



27.0 



63 



9.3 



402 



178 



44.2 



193 



48.1 



31 



7. 7 



569 



312 



54.8 



200 



35.2 



57 



10.0 



A stud}^ of this table will show that the wrapping reduced the number 

 of crown-gall trees y^vy materially, but the results given should be 

 considered as ])reliminary and the figures as relative rather than abso- 

 lute. Only a small number of the trees under test have so far been 

 dug. The remainder will be dug after one or two years' growth. 



The most effective wrapping., so far as the true crown-gall is con- 

 cerned, was that made of rubber (86.5 per cent of smooth trees), fol- 

 lowed closely by cloth (85.1 per cent of smooth trees). The cloth wrap- 

 ping, however, shows the highest percentage of smooth trees per 100 

 grafts planted when not onh^ the crown-gall but also the hairy-root 

 are considered. The difference is veiy slight, however. The other 

 wrappings show less favorable results, least of all in the case of the 

 grafts wrapped with plain thread and covered with grafting wax (44.2 

 per cent of smooth trees), followed closely by those with no wrapping- 

 whatever (54.8 per cent of smooth trees). 



RECOMMENDATIONS. 



From the results so far obtained, the use of either cloth or rubber as 

 material for wrapping apple grafts is recommended. Owing to the 

 expense involved in the use of rubber, cloth will be found the most 

 desirable, and in most cases will probabh^ give results fully as satisfac- 



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