112 
THE NATIONAL NURSERYMAN 
divaiii of ordering from a catalog or even buy from a 
nursery agent. 
After all there are potential possibilities for the nur¬ 
seryman in the stores handling their goods. If ways 
could be found by which good quality stock could be sold 
al fair prices. 
Then* is another phase of the subject, which is worth 
consideration, and that is the person who would buy nur¬ 
sery stock from a department or other store is not one 
w ho would likely buy from any other source and once 
started with even poor stock it is likely to begin an inter¬ 
est in growing and buying of the nurseryman’s products, 
from which the grower will ultimately benefit. 
Then* have been many thoughtful men who have taken 
the stand that it is even profitable for tbe nurseryman to 
give his surplus away rather than destroy it, contending 
that when a person once becomes interested and gets the 
planting habit they are potential customers. It is a well 
known fact that in localities where nurseries are located 
and where well planted gardens are very numerous there 
is always a greater demand for the nurseryman’s pro¬ 
duct. than in other localities where little or no interest 
has ever been taken in fixing up home surroundings, so 
that after all the cheap plants in the ten cent stores may 
not be an unmixed evil. 
BLIGHT RESISTANCE IN PEAR STOCKS 
By A. C. McCormick, Husum, Washington 
Considerable interest is being shown in the propagation of 
blight resistant pear stocks by nurserymen on the Pacific Coast 
and in the Middle West. 
There is little published information on this subject which is 
available to nurserymen. Therefore, no doubt, a brief history 
of the development of these stocks will be of interest to pro 
pagators of fruit tree seedlings. Realizing the importance of 
pear culture in Oregon, the Oregon Experiment Station estab¬ 
lished a branch station at Talent in 1911, known as the South¬ 
ern Oregon Experiment Station. The purpose of this station is 
fundamentally to investigate and discover remedies to combat 
and eradicate pear blight in the pear Orchards. 
There were several fortunate coincidences with respect to the 
establishment of this experiment station. Chief among them 
was the appointment of Prof. F. C. Reimer as director of this 
station, and the fact that it was located in the heart of the pear 
growing industry of Oregon, in the Rogue River Valley. Blight 
had by this time become firmly established in this pear district 
and had wrought considerable damage, even threatening the 
industry. Pear growers were greatly alarmed lest they should 
lose their orchards, having known that this fate had befallen 
many growers in California a few years previous. 
After his appointment Prof. Reimer immediately set about 
collecting all known species of Pyrus from many parts of the 
world, and brought together a vast collection of pear varieties. 
The ultimate object of the research was to test these for their 
relative susceptibility and resistance to the blight organism. 
This work progressed slowly at first because in many cases 
the various species of Pyrus had to be multiplied from a single 
scion stick, the supply being so limited. It was not until 1916 
that the testing of these varieties and species was commenced 
on a large scale. Most of the work was conducted in the nur¬ 
sery rows where the plants were growing in a most vigorous 
and succulent manner. Pure cultures of the blight organism 
were used to make inoculations. 
This work immediately revealed the fact that the French pear 
seedling stock was extremely susceptible to blight, and that 
the Japan pear was considerably less susceptible but the de¬ 
gree of resistance was far below immunity. Many other species 
were tested and among them two of Chinese origin showed 
great promise. These were P. calleryana and P. ussuriensis. 
Prof. Reimer’s collection of these species at this time was very 
limited as he had only a few types of each species and only the 
wild type of P. ussuriensis. 
In 1917 Prof. Reimer determined to make a trip of exploration 
to China and by the aid of the State and Federal Governments 
(and considerable expense to himself) funds were provided for 
this trip. He made extensive explorations in Japan, Manchuria, 
Korea, central and northern China and from every quarter col¬ 
lected scions and seeds from both the wild and cultivated pears. 
With this most valuable collection of material, returned from 
the Orient and proceeded to inoculate these new plants which 
he had obtained in China with the pear blight organism. Re¬ 
sults from this work substantiated his former data on the re¬ 
sistance of these species. 
While the wild form of P. ussuriensis is almost immune to 
pear blight and while it attains great size and is extremely 
hardy, yet it is unsuitable as a stock because our commercial 
varieties do not make a perfect union with it. This wild form 
starts growing very early in the spring and by early summer 
the new wood growth has matured. P. ussuriensis is indigenous 
to northern China and Siberia, where the winters are very rig¬ 
orous, and hence is a very hardy species. Plants obtained from 
the seeds and scions of the cultivated varieties of P. ussuriensis 
exhibited great resistance to pear blight. Stocks grown from 
seeds of these cultivated P. ussuriensis make perfect unions 
with our commercial pears (P. communis). 
To obtain these seeds, seed-collectors must first buy the fruit 
from the Chinese pear growers and extract the seed. This fact 
alone shows that the seed will cost considerably more than 
Japan pear seed (P. serotina) for instance. Cheap seed of P. 
ussuriensis, therefore, must mean that it is not of the most de¬ 
sirable type of this species. 
Pyrus calleryana, the other blight resistant species, is found 
over a wide area in eastern Asia and is particularly abundant in 
central China. The types of this species appear to be regional, 
that is, the type in the far north is dwarf or shrub like, the 
central type fully deciduous, while the southern types are 
almost evergreen. In its native country P. calleryana grows 
under a wide diversity of soil conditions as well as that of cli¬ 
mate. It occurs in central China from a few feet above sea 
level to that of 5000 feet elevation. It is found growing along 
streams and again on dry hill sides. 
The graft union of P. calleryana with our cultivated varieties 
of pears is entirely satisfactory, and, due to the abundance of 
this species in its native land, the matter of seed collection is 
relatively more simple than that of P. ussuriensis. But here 
again growers must be cautious to obtain their seed from the 
most reliable sources. There are two chief reasons for this, 
first, the seed may be impure, and second, it may be of the 
southern type. This is not necessarily due to intentional dis¬ 
honesty on the part of seed collectors, but rather through lack 
of familiarity with the species and its habits. 
Impure seed is the result of the confusion of P. calleryana 
and P. betulaefolia, the latter being very similar to P. callery¬ 
ana and extremely susceptible to pear blight. P. betulaefolia is 
one of the most susceptible of all pear species to this dreaded 
disease. These two species grow together in the forests of 
China, and the seed collector if he is not most familiar with 
these two species is liable to confuse them and collect seed 
from both, not aware of the fact that they are two distincf 
species. The southern type is to be avoided because of its ten¬ 
dency to remain over winter as an evergreen in America. 
P. calleryana and P. ussuriensis are being grown on the 
Pacific coast under the term of Chinese stocks as distinguished 
from the Japan seedling. 
There are certain factors in growing Chinese stocks which 
will offset the greater cost of seed per pound. The chief ad¬ 
vantage is that the percentage of germination is much higher. 
It is a well known fact that Japan pear seed must be handled 
with extreme care in respect to moisture in order to insure 
proper germination. The danger of rotting is considerably less 
with the Chinese seeds. Ordinarily P. ussuriensis will germinate 
about two weeks earlier than the Japan pear seed. The seed 
of P. calleryana is so small that a pound of this species will con¬ 
tain approximately three times as may seeds as either P. ussur- 
