CULTURAL METHODS IN ORCHARDS 



169 



Table XLVI 



influence of cultural treatments on the growth of trees 



average gain in trunk-girth to a tree. no fertilizers or manures 



USED.l (after STEWART) 



the conditions obtaining in this experiment, the growth was 

 not being maintained by this treatment, as is shown by the 

 data at the end of the first and second five-year periods. On 

 stronger soils, the time would be delayed when such a de- 

 cline would begin to be evident. When fertilizers were 

 added, both the cover-crop and trees showed the growth 

 to be in an increasing ratio rather than in a decreasing one. 

 This means that tillage with cover-crops is somewhat su- 

 perior to tillage alone, but a lighter soil will show the lack 

 of green-manuring before a stronger one, the length of time 

 depending on the original fertility of the soil. 



1 Pcnn. Agr. Exp. Sta. Bull. 141. 1916. 



