WINTER PRUNING EXPERIMENTS WITH APPLE TREES. 139 
WINTER PRUNING EXPERIMENTS WITH APPLE TREES. 
By N. H. Grubb, M.Sc, East Mailing Research Station. 
[Read October 18, 1921 ; Mr. C. T. Musgrave in the Chair.] 
At the foundation of the East Mailing Research Station in 1912, the 
programme drawn up by the first Director, in conjunction with the 
Governing Body, included an extensive series of experiments on the 
winter pruning of Apple Trees. For this purpose a number of 
"maiden" (one year) Apple Trees were planted at the end of 1913, 
and others a year later ; these trees were thus, up to the winter of 
1921-22, nine and eight years old from the bud respectively, and 
a year less from planting. From 1919 onwards they have yielded a 
considerable quantity of fruit, and it is thought that the mass of 
records accumulated justifies the issue of a first report. 
Since much knowledge on points of vital importance in all fruit 
research has been gained since 1913, it will be understood that some 
points in relation to the trees are open to doubt. It was not known 
until a year or two later to what an extent the so-called ' Paradise ' 
stocks were mixed and wrongly named ; but as the trees were obtained 
from ordinary trade sources, they are strictly comparable, as far as 
stocks are concerned, with the trees commonly planted for commercial 
purposes. It has already been possible, by means of suckers, to 
identify a small proportion of the ' Paradise ' stocks represented ; 
at least four types have been found. Ultimately, it is hoped, all 
the ' Paradise ' stocks will be identified by means of root cuttings. 
There remain seven lots of trees (out of twenty) on ' Crab ' stocks ; 
while they are fairly representative of this class of tree, they are of 
course very variable, and the average of the eight trees in each group 
is none too safe a guide as to the effects of the different methods of 
pruning. There are, however, Only two varieties of apple in the 
experiment, of which trees on ' Crab ' stock alone are available. Of 
five others a similar number of trees on ' Paradise ' forms a check to 
those on ' Crab ' ; of the remaining eight varieties in the experiment 
only trees on ' Paradise ' are available. 
The trees were specially selected from a large number in the 
nurseries from which they were obtained, all being strong " maidens " 
of the greatest possible uniformity in height and stoutness. In this 
respect the trees were very much better than those commonly planted 
by market growers. 
The trees were all cut approximately two feet high from the 
ground shortly after planting, and the new shoots they formed were 
all cut hard back and spaced in each of the two following winters. 
Thus to the age of three years from the bud all the trees were treated 
exactly alike, and any effects of the different methods of pruning 
subsequently employed are, up to the present, the result of six years' 
