CULTURAL METHODS IN ORCHARDS 



171 



142. The Woburn experiments.^ — The work of the 

 Wobum Experimental Fruit Station on the effect of sod on 

 the growth of trees is of special interest, since it is viewed 

 from the standpoint of the toxicity of the soil. The results 

 there are not paralleled in this country so far as the extreme 

 effect of sod on trees is concerned. It was found that young 

 orchards planted in sod made a feeble growth and soon 

 reached the point of death if not tilled. No form of ill- 

 treatment would produce such enfeebling results with the 

 exception of transplanting the trees each year. Not only 

 did trees planted in sod show this effect, but those which 

 had made a vigorous growth in tilled land for a period of 

 four years showed the ill effects at once when the land was 

 laid down to grass. Within five years most of the trees of 

 the weaker varieties were entirely dead. The work was 

 repeated under vaiying conditions, with different varieties 

 and with both standard and dwarf kinds. Some vari- 

 eties proved resistant to the effect of the grass, but mostly 

 they suffered extensively. Different kinds of fruits varied 

 in their behavior toward the sod as is seen by the following 

 data: 



Table XLIX 

 values compared with ungrassed trees = 100 



(after BEDFORD AND PICKERING) 



When grassed trees in low vitality were again tilled, they 

 made an immediate response to the culture. (This was also 

 the experience of Hedrick in the Auchter orchard.) Con- 

 1 Woburn Exp. Fruit Farm Kept., 1, 2, 3, 13, 14. 



