Effect of Biennial Bearing 

 On Size and Yield of Fruit 

 In the Northern Spy Apple 



In a comparison of Northern Spy 

 trees, which are strictly biennial in 

 bearing habit, with those which have 

 been producing crops of equal size 

 from year to year, it was found that 

 over a four-year period the regular 

 bearing trees have produced a larger 

 crop than have the biennial bearers. 

 Furthermore, the annual bearing 

 trees have produced better sized 

 apples. The heavy load of fruit pro- 

 duced by the biennial bearing type 

 causes considerable reduction in the 

 size of the fruit. 



L. P. Latimer 



Effect of Hay Mulch on 

 Northern Spy Apple Trees 



Northern Spy trees mulched with 

 hay, but not receiving any nitro- 

 genous fertilizer, have outyielded 

 those grown in sod and fertilized 

 with nitrogen. When either phos- 

 phorus and potash, or phosphorus 

 and potash plus nitrogen, are sup- 

 plied to trees mulched with hay, the 

 yield is depressed, the g;reatest de- 

 pression in yield occuring with trees 

 receiving the three elements nitrogen, 

 phosphorus and potash. 



L. P. Latimer 



leaf Scorch of Apple Trees 



The prevention of leaf scorch, a 

 physiological disorder, resulting 

 from a deficiency of magnesium in 

 the tree, is of economic importance 

 in certain apple growing areas, par- 

 ticularly with respect to the Mcin- 

 tosh variety. The application of in- 

 organic salts of magnesium to the 

 soil, either by broadcasting them on 

 the soil surface or by placing them 

 in holes bored in the soil under and 

 about the trees has failed to remedy 

 this condition. On the other hand, it 

 has been strikingly demonstrated that 

 a surface mulch of hay placed under 

 affected trees and out just beyond 



the spread of the branches will alle- 

 viate this leaf scorch. The improve- 

 ment is gradual, the full effect not 

 being realized until two or three 

 years after first applying the mulch. 

 The leaves of trees mulched with 

 hay actually contain more magnes- 

 ium than do those mulched with saw- 

 dust or those left unmulched. 

 L. P. Latimer 



A New Apple Rootstock 



Seeds of a species of apples — 

 Mains Sikkitnensis — from Skkim, 

 India, were obtained from Dr. Karl 

 Sax of the Arnold Arboretum, who 

 suggested that it might have possi- 

 bilities, judging from the behavior 

 of a Mcintosh tree growing on this 

 stock at the Arboretum, as a dwarf- 

 ing stock for apple varieties. Malus 

 Sikkimensis seeds, being apomictic, 

 produced a very uniform stand of 

 seedlings. These seedlings were 

 budded with the varieties Mcintosh, 

 Early Mcintosh, Cortland, Northern 

 Spy, Macoun, Golden Delicious, and 

 are now in their third growing sea- 

 son. This stock is apparently quite 

 vigorous in the nursery as first year 

 whips were 5-6 feet long. The varie- 

 ties grown on these seedlings seem 

 to have unusual wide angle branches 

 and show a tendency even in their 

 third growing season to spread into 

 a wide tree. 



This rootstock has several good 

 features in that it is apomictic — 

 producing uniform seedlings, ap- 

 parently hardy, it seems to be com- 

 parable with all varieties worked in- 

 to it, and has a favorable influence 

 on shape and size of the tree. A 

 uniform rootstock produced from 

 seed would be much less expensive 

 than one that had to be propagated 

 as from a stool bed. 



Mains Toriiigoides — also obtained 

 from Dr. Sax — is not as promising 

 and is more difficult to handle in 

 the nursery. 



W. W. Smith 



27 



