PLUMS IX RELATION TO PRUNING 33 
the tree. Under conditions favorable to wood growth the branches continue to 
lengthen from year to year, although sending out but few if any fruiting 
branches, whereas under adverse growing conditions terminal fruit spurs form 
on the ends of branches (pi. 34, C). Because of the little branching, unpruned 
trees become very open if wood growth is slow ; but with the appearance of 
twigs and small branches and the length growth of spurs, they maintain a good 
supply of fruiting wood. 
Vigorous spurs are produced along the entire length of all branches and 
twigs and remain thrifty and productive throughout the tree, even under 
somewhat adverse growing conditions. The vigor of the spurs and the tendency 
for the tree to produce and retain them are more pronounced in this than in 
other varieties commonly grown (pi. 31, C). Where not crowded the spurs are 
much branched, and all branches make considerable terminal growth. The 
growth of spurs of this variety, which sometimes reaches a foot or more in 
length on old trees, is more pronounced than with other varieties ; and by 
pruning or otherwise improving conditions for wood growth, a vigorous twig 
is often produced from a spur (pi. 35, A). Trees on which the 1-year wood is 
regularly and severely headed back produce an abundance of vigorous spurs and 
twigs throughout the tree (pi. 34, B, and pi. 35, B). Toward the end of vigorous 
young branches, short twigs sometimes appear in place of spurs. These twigs 
make a spreading growth of moderate length and produce numerous fruit 
spurs which bear a heavy crop, causing the longer and the more slender branches 
to spread or droop. 
Fruit is borne almost entirely on "growing spurs and at nodes of short 1-year 
branches where spurs or twigs are forming. This indicates the strong 
vegetative vigor of the fruit wood of this variety. The fruit is often numerous 
on short, compact much-divided spurs on wood 2 and 3 years old where the 
spurs have made but little growth in length. The strong tendency to form spurs 
at all nodes of the 1-year-old branches leaves but few barren nodes in any 
part of the tree, even where heavy crops are borne on the young wood. 
Pruning to establish a good number of framework branches, shortening these 
to establish and maintain strong upright branches, and developing spurs and 
twigs on them should result in a productive and satisfactory tree. Although 
trees of this variety are often left unpruned, they will probably withstand 
severe pruning with as little ill effect as any commercially grown variety. 
If the soil is fertile and well watered, they will continue thrifty and produce 
with little pruning. 
Although the size and shape of trees of this variety are greatly influenced 
by environment, their growth and ability to stand drought are shown by the 
persistence of their spurs and the thrifty green color of their foliage, which 
often remains for a considerable period after drought has caused leaves of 
other varieties to become discolored or to fall. 
Tree very prolific, only moderately vigorous. It branches sparingly with 
the exception of the growth of twigs and spurs and is therefore naturally 
open. The branches are inclined to be more slender than those of most 
varieties, and they increase in diameter very slowly if not headed back to 
induce branching. The tree is inclined to produce new shoots from the terminals 
of branches rather than to form new branches, and there is but little terminal 
growth of unpruned branches after the first few years unless other conditions 
are very favorable. 
Bearing trees produce almost no branches aside from those which appear 
following pruning ; but by regular heading back the new shoots make a 
moderate upright growth, starting from the nodes of the 1-year-old stubs, so 
that by regular heading back a compact upright tree may be developed (pi. 
36, A). As the new shoots start from near the point of pruning it is important 
that the supply of 1-year-old wood left after pruning be the length desired 
before the next branching takes place. If long sections of the 1-year shoots 
are left in pruning, the trees will be too open and the larger part of the fruit 
crop will be at a greater distance from the ground than is necessary. Although 
the shoots which grow from headed-back branches are fewer than are found 
on most varieties and shoots seldom appear along the older wood, many twigs 
and short branches which are the outgrowth of spurs are produced along the 
older branches of trees which have been headed back. This growth remains 
27428°— 27 3 
