PLUMS IN RELATION" TO PRUNING 7 
and cutting these back sufficiently to insure the desired new wood 
growth, spurs and twigs should develop promptly. 
With a few varieties the large vigorous shoots growing from stubs 
of branches of thrifty trees which were severely headed back send 
out short and slender but strong twigs along the lower part of the 
shoots during their first summer's growth. These twigs appear early 
in the summer and grow at right angles to the main shoot. They 
produce fruit at leafless nodes along much of their length when one 
year old, but spurs are produced at a few nodes near the end. Such 
twigs make but little length growth after their first season, but their 
spurs are prolific and long lived and retain vigor well even in moder- 
ate shade. Their appearance on new shoots indicates that the tree is 
thrifty and is inclined to bear its fruit on spurs instead of twigs. As 
these twigs appear well down along the shoots and remain prolific for 
a period of years, they should be spared and given light, and care 
should be taken that they are not broken during cultural operations. 
This type of growth is common with only a few varieties and these 
are in the domestica group. The President furnishes the best exam- 
ple (see pi. 32, B). In the Japanese group the Duarte is similar to 
the President in regard to the branching of the current season's 
shoots, but with the Duarte the twigs appear at somewhat less than 
a right angle to the parent branch, are slender and become drooping 
after bearing fruit, but are vigorous and continue fruitful for a 
number of years (see pi. 8, A). Trees below normal in vigor or 
those growing under unfavorable conditions and those not headed 
back in pruning seldom produce this type of twig. 
Short right-angled spurlike twigs sometimes appear also near 
the tip of shoots during their current season's growth if the growth 
of the tree is checked by drought, the attack of insects, or otherwise. 
Shoots which make a long, vigorous, whiplike growth start, for 
the most part, near a cut made in pruning, along the main limbs, 
and at the highest point of bending branches. The number of these 
shoots and the extent of growth made vary decidedly with the va- 
riety and with treatments which influence wood growth, the prin- 
cipal one of which is pruning. On 1-year-old wood which has been 
headed back, the growth of new shoots is, to a large degree, pro- 
portionate to the severity of the pruning. With some varieties the 
vegetative vigor appears to be very largely centered in the stubs of 
headed-back branches and almost all new snoots appear there. With 
other varieties given the same treatment the appearance of new 
shoots is distributed more or less throughout the tree. Trees of 
varieties which produce stout lateral spurs along the branch, but 
make only a few twigs and fruiting branches and remain open, are 
inclined to produce their new shoots near the ends of stubs of 
branches which have been headed back or near where branches have 
been removed. With those more inclined to produce twigs, new 
growth often appears along the older branches as well as on stubs 
of headed-back branches. Gaviota, Beauty, Tragedy, and Santa 
Kosa belong to the latter group, and Sergeant, Formosa, President, 
and Peach to the former. 
If the trees have been pruned lightly or not at all and the soil 
moisture is somewhat below their needs there will be but a small 
extent of new wood growth, and the upper branches of open-grow- 
