Grosseribacker—Radial Growth in Trees. 
45 
cases it was found to occur equally late in the upward extension 
of such a root-ridge on the trunk. Again, in some instances in 
which trees had only two large lateral roots making a rather 
narrow angle with each other, very late growth was found to oc¬ 
cur in the valley-like angle between them. From an earlier pa¬ 
per 88 on crown-rot and the papers cited there it is interesting 
to notice that the distribution of that disease on fruit trees con¬ 
forms fairly closely to the distribution of late radial-growth oc¬ 
curring at the root-crown region. It was found that in cases 
where only a part of the bark was affected it was confined to the 
upper angles of lateral roots, or to the very deep angles between 
two large laterals. 
Pruning fruit trees very heavily often results in a decided re¬ 
duction in the thickness of the next annual ring toward the base 
of the trunk. This was found by pruning some fruit trees in 
one of the seedling apple orchards of the New York State Agri¬ 
cultural Experiment Station in early spring of 1912. The ra¬ 
dial growth on the lower part of such heavily pruned trees also 
continued several weeks later than it did on nearby checks.* * 
The result seems to agree with those obtained by Jost, Lutz, 
and Kuhns 89 in that a reduction of the foliage beyond a certain 
amount resulted in greatly reducing growth toward the base of 
the stem. 
As stated above observations made regarding the occurrence of 
crown-rot on fruit trees seemed also to show a possible relation 
of that disease to the distribution of late growth. Some New 
York apple orchards may be used to illustrate this relation. In 
one instance 90 two varieties almost equally susceptible to crown- 
rot were grown side by side and received the same treatment ex¬ 
cept that the Baldwin variety was pruned up high while the 
other or Ben Davis variety was allowed to grow largely unpruned 
and therefore low headed. The Ben Davis trees had been set 
for fillers and were not deemed worth the care bestowed on the 
88 Crown-rot, arsenical poisoning and winter-injury. N. Y. State 
Agrl. Expt. Sta. Tech. Bui. 12:389-94. 1909. 
* The writer wishes to thank G. H .Howe of that station for having 
the pruning done, and R. Wellington, now of the Minnesota Experiment 
Station, for making some of the collections of specimens from these 
trees into killing fluids. 
89 1. c. 
90 Crown-rot of fruit trees: field studies. N. Y. State Agrl. Expt. Sta. 
Tech. Bui. 23:18-20, 48, and plate 7. 1912. 
