MULCHING IN BEARING APPLE ORCHARDS 11 



make a clearer picture of the general tendency, the yields are shown in the figure 

 by two-year periods in average pounds per tree. 



Considering Mcintosh during the first six years, the trees in cultivation 

 yielded less than the mulched trees and there is a tendency towards a widening 

 of this difference which is marked in the next biennium, 1928-29. It was 

 this that suggested the necessity of applying nitrogen to the cultivated plots 

 if yields were to be maintained. The use of nitrogen on the cultivated plot 

 was followed by a sharp increase in yield which was made more striking by 

 the heavy crop in 1930 when the trees were still unfertilized but which was a 

 heavy crop year when all sorts of trees bore unusually heavy crops. In these 

 last six years the lines are nearly parallel and suggest that had the cultivated 

 plots been fertilized during the entire period, the yields might not have been 

 so far apart. 



In the case of Wealthy on standard stocks, the yield on the cultivated plot 

 was larger at the start but soon fell below that on the mulched plot. There 

 is no striking response from the nitrogen applied in 1931, as the yield on this 

 plot increased no more than that on the mulched plot where there was no 

 change of treatment. In fact there is a falling off in the last biennium. The 

 same is true of Wealthy on Doucin stocks, except that the yield on the culti- 

 vated plot has been lower all the time. It has been shown that there has been 

 a great excess of nitrates in the mulched plot, and it may be that nitrates in 

 the drainage water passing down the slope on the compact subsoil have supplied 

 the trees in the cultivated plot with the required nitrogen. 



Many fruit growers may find it easier to think in terms of bushels per acre 

 than to read a graph. In Table 5 the average annual yields in pounds per tree 

 have been converted into bushels per acre. A unit of a 50-pound bushel has 

 been used, although a bushel of these varieties weighs around 45 pounds or 

 less. The yield records include all fruit on the ground, some of which is worth- 

 less, and it is thought that a 50-pound bushel gives a fairer basis of compilation. 

 In choosing the number of trees per acre, Mcintosh yields are computed on 

 the basis of 27 trees per acre, or approximately 40 x 40 feet, the distance at 

 which they stand in this orchard. The standard Wealthy yields are computed 

 on the basis of 35 trees per acre or approximately 35 x 35 feet and the Doucin 

 Wealthy at 108 trees per acre or 20 x 20 feet. Actually, the standard trees were 

 40 x 40 feet interplanted with the dwarf trees bringing the distance to 20 x 20 

 feet. 



This table shows the tendency for the Mcintosh to alternate following the 

 heavy crop of 1930 and the distinct alternation of the Wealthy trees during the 

 entire period. The larger acre yields of the dwarf trees should not be taken too 

 seriously, as the planting distances assumed are arbitrary and a change would 

 alter the figures. However, the assumed distances are reasonable, and the 

 figures indicate that a dwarf Wealthy orchard on this particular stock (Mailing 

 V) might be expected to yield at least as well as the usual kind of trees. 



No data concerning the size or quality of apples produced under the two 

 types of soil management have been collected, but observation indicates little 

 difference. Apples from the mulched plots have been slightly later in maturing 

 in some years; the green undercolor has been a little slower in developing. 

 There has been little difference in the red coloration. The dwarf Wealthy trees 

 have produced somewhat smaller apples than those on seedling roots. 



