New York Agricultural Experiment Station. 545 



being of his trees even though reliance must be placed on the eye 

 alone to secure evidence. Judged by color of foliage there was, 

 in any year, no time while the leaves were out that even the novice 

 in fruit-growing would not have declared the tilled trees the more 

 vigorous and healthy. The pale, sickly color of the sodded trees 

 could be distinguished from the rich green of those under tillage 

 fully a half mile away as one approached the experimental plats. 



The appearance of the foliage of sodded trees is so characteristic 

 that we venture the assertion that we can recognize a sod-bound 

 apple-tree from its unthrifty foliage, mulch or no mulch, find it 

 where you may in western New York, at any time from June to 

 October. In passing, it must be said that, everywhere in New York, 

 in driving by orchards the tell-tale tints of the leaves speak con- 

 vincingly of the better health and greater vigor of tilled apple- 

 trees to those who have eyes to see. 



Number and size of leaves. — The number and size of the leaves 

 tell the same tale of some kind of interference in the protoplasmic 

 activity in the leaves on the sodded tree. It required but a glance 

 to satisfy oneself that the leaves on the tilled trees were larger and 

 more numerous, and therefore total leaf area much greater on the 

 tilled than on the sodded trees. Undoubtedly the number and 

 the size of the leaves shut out the sunlight somewhat from the fruit 

 and thus help to account for its later maturity and poorer coloring 

 on the tilled trees. Plates XLIX and L give some idea of the relative 

 size and denseness of the leaves in the two plats. 



In the first report on this experiment an attempt was made to 

 measure roughly the relative efficiency of the foliage of the trees 

 under the two treatments by weighing leaves. 1 It was found, in 

 short, that the leaves of the tilled trees weigh one and one-third 

 times as much as those of the sodded trees indicating one and one- 

 third greater efficiency of the foliage of the tilled trees. 



Leafing-ti?ne and fall of leaf. — Not only were the leaves on the 

 tilled trees more efficient in furnishing food for the trees because 

 of more chlorophyll and greater size and larger numbers but they 

 remained on the trees longer at both ends of the season and thus 

 contributed to superior vigor and health. The leaves of the tilled 

 trees came out from two to five days earlier in the Auchter orchard 

 and remained on from a week to two weeks longer. In the northern 



1 N. Y. Sta- Bui. 314: 105. 1909. 

 35 



