No. 6. DEPARTMENT OF AGRICULTURE. 401 



Average yield per acre on the plots for the five years: sod, 72.9 

 barrels; tillage, 109.2 ban els; ditterence in favor of tillage per acre, 

 36.3 barrels. These results scarcely need comment. For an aver- 

 age of five years the tilled plot shows an increase of a little over one- 

 fourth above the sod-mulch plot. The figures first read show that 

 each succeeding year the difference becomes greater, indicating a 

 continuous loss of vigor in the sod-mulch trees. 



One of the chief advantages of the sod-mulch method, as put 

 forth by its promulgators is, that it is a much less expensive method 

 of caring for an orchard. The average expense per acre of the two 

 methods of management for five years was $17.92 for sod; and 

 $21.47 for tillage, a difference of |G.5.5 in favor of the sod. It is 

 true that the outgo lias been greater for the tilled plot but the in- 

 come has been greater. The cost of production has been materially 

 less for the tilled trees and that is the main point in the whole dis- 

 cussion. A cheap and easy way of growing apples is not necessarily 

 the most remunerative way. 



Leaving the yield of fruit for a brief consideration of the effects 

 of the two treatments on tree characters we can mention first 

 the leaf area. Measureruents of leaf area were not made but the 

 merest glance through the orchard would show that there were more 

 and larger leaves on the tilled plot than on the sod-mulch plot. The 

 experienced orchardist knows that sparsity of foliage and smallness 

 of leaf can indicate but one thing, ill-health. 



So, too, there was something amiss with the color of the leaves. 

 It did not need a trained eye to detect the difference in color of fol- 

 iage in the two plots. The dark and rich green of the tilled trees 

 could be noted a half mile from the orchard indicating an abundance 

 of food and moisture and the heyday of health, while from the same 

 distance it could be seen that the foliage of the sod-mulch trees was 

 pale and sickly. Of all the signs of superiority of the tilled trees 

 the color of the foliage spoke most eloquently and more ihan one 

 man of the hundreds who visited the orchard was heard to say 

 as his eyes lighted on the contrasting colors of the sick and of the 

 well trees "that satisfies me.'' The absence in color in the leaves of 

 the sod-mulch trees was due to a lack of chlorophyl or leaf-green. 

 Chloi'ophyl is essential to the assimilation of plant-food and when 

 it is lacking the trees become starved and stunted. The leaves on 

 the sod-nrulch trees assumed their autunrnal tints a week or ten days 

 earlier than those on the tilled trees and the foliage dropped that 

 much earlier, thus seriously cutting short the growing season of the 

 grassed trees and thereby impairing their future vitality. 



The new wood produced by the grassed trees tells a similar tale 

 of injury. It was not half that produced on the tilled trees; the 

 twigs were not plump and well filled out; there were fewer new 

 shoots ; and the wood of the mulched trees lacked the clear, bright, 

 rich broM-nish tint of health so that in mid-winter one could pick 

 out mulched trees and tilled trees by the color of the wood. 



As to color there is no question but that the fruit from the sod- 

 mulch plot is much more highly colored than that from the tilled 

 plot. This difference varies with the season. Mulched fruit ripens 

 from a week to two weeks earlier than tilled fruit. If the variety 

 and the season are such that the tilled fruit can remain on the trees 



26—6—1911 



