ROOT-KILLING OF APPLE TREES. 465 



The stocks for a fair test should be handled much like the Ma- 

 haleb or Mazzard stocks for the cherry in the eastern nurseries, set- 

 ting- the stocks in nursery first, and afterwards, when established, 

 budding- the cultivated apples upon them. 



It will take many experiments to fully settle the question. Let all 

 who can try a few and report results. In the meantime, we strongly 

 advise watering trees if possible before the ground freezes in the 

 fall, and then applying a heavy mulch also before the ground 

 freezes, to prevent too severe freezing of the roots. 



SUMMARY. 



1. By the word "stock," nurserymen mean the tree or root upon 

 which a tree is grafted or budded. 



2. The ordinary American and French apple seedling-s {Pyrus 

 malus), now used as stocks for the cultivated apple, are not suf- 

 ficiently hardy over a large part of the prairie northwest in severe 

 winters. This causes root-killing, and the hardy top, thus left with- 

 out a root to support it, necessarily perishes. 



3. The American wild crab {Pyrus ioensis), as found native at 

 Des Moines, Iowa, winter-killed at this station, and hence is not suf- 

 ficiently hardy to use as a stock. It has not been found native in 

 South Dakota, save in the southeastern corner. 



4. The experiments at this station show that the roots thrown out 

 from the scion in root-grafts of the hardy varieties of the cultivated 

 apple are hardy in ordinary winters, but did not prove hardy the 

 past severe winter (1898-'99), minimum temperature forty degrees 

 below zero Fahrenheit with the ground bare. 



5. Limited experience with seedlings of hardy varieties of the cul- 

 tivated apple at this station indicates that they will not be exempt 

 from root-killing in winters like that of 1898-'99. Seedlings of the 

 wild apple from the province of Kursk, southern Russia, also proved 

 subject to root-killing. 



6. Top-grafting on Siberian crabs has not proved generally suc- 

 cessful. Piece-root grafting on Siberian crab seedlings has not 

 proved successful, as tried by a number of northwestern nursery- 

 men. 



7. The commercial naethods of propagating apple trees in Ameri- 

 can and European nurseries are described. In the nurseries of 

 Europe and the eastern United States, budding upon seedlings 

 previously planted in the nursery is preferred to piece-root grafting 

 in winter. In the western nurseries piece-root grafting with a long 

 scion and short root is the better method, as it puts the tender seed- 

 ling root further beneath the surface. 



8. The true Siberian crab [Pyrus baccata) is the hardiest known 

 species of the apple, and if it proves sufficiently exempt from blight 

 may prove of great value as a stock in sections where root-killing 

 is a source of trouble. Young plants of this species proved per- 

 fectly hardy the past winter on the grounds of this station. 



9. Translations from Russian authorities are given to aid in dis- 

 tinguishing Pyrus baccata from other closely related crabs. 



