THE NATIONAL NURSERYMAN 
ROOTSTOCKS USED BY CALIFORNIA NURSERYMEN 
DURING 1922 
By Myer J. Heppner, Assistant in Pomology, University of 
California 
During the early part of 1923 the writer sent a questionnaire 
to practically all of the large nurserymen propagating deciduous 
fruit trees in California in order to determine what rootstocks 
they used for the different fruits during the year 1922. The sur¬ 
vey met with the approval of the nurserymen as was evidenced 
by the large number of answered questionnaires returned. 
Two vital points were brought out by the survey: 
1st—The proportion of rootstocks used for each kind of fruit 
is not the same as it was in 1917, 1918 and 1919, when similar 
surveys were made by Dr. W. L. Howard, of the Division of 
Pomology, and 
2nd—Nurserymen do not agree as to the relative merits of the 
various rootstocks. 
The first can possibly be accounted for by the fact that grow¬ 
ers are getting away from the traditions of the past and are now 
making this own observations as to which rootstock is best adapt¬ 
ed to their conditions. In other words, the competition in fruit 
growing has become so keen that the grower thinks twice before 
ordering his trees on a certain stock. He cannot afford to make a 
mistake in selecting the foundation of his orchard. As has been 
seen time and time again, many growers “have gone to the 
wall” due to the selection of the improper rootstock for their 
trees. The California horticulturist has come to a point where 
he finds it advisable to discard the rules set by his forefathers. 
Like many other enterprises, the business of fruit production 
is changing from year to year and in order to keep pace with 
these changes the successful orchardist must change his view¬ 
point so as to fit in with these conditions. Before the advent of 
irrigation, the orchardist did not have to worry about any rising 
water-table drowning out the root system of his trees. Today 
this question must be given a good deal of consideration. There 
are certain rootstocks that can withstand “wet feet,” while to 
other stocks this would mean destruction. This is one example 
of many where the orchardist of today must see things as they 
are today and forget about conditions as they existed thirty years 
ago. 
The fact that nurserymen of the state do not agree on the val¬ 
ues of the different rootstocks for the different fruits is of great 
interest and clearly shows that California should have started 
a systematic study of the rootstock problem long ago. Growers 
and nurserymen have always felt such a need, but nothing was 
done until the past two or three years when the Division of 
Pomology of the University of California undertook such a study. 
One of the questions asked in the questionnaire recently sent 
out, was, “What about the sweet cherry on Mahaleb stock in 
California?” Some of the replies were: 
1. “I see no objection to Mahaleb root other than that it is 
a dwarf and the trees grow smaller.” 
2. “0. K.” 
3. “Equally as good as Mazzard on any well drained soil.” 
4. “If grafted low, Mahaleb is preferable in all soils.’ 
5. “Do not use it.” 
6. “Not desirable.” 
7. “Mazzard is best root.” 
8. “No good.” 
The above replies were taken from the questionnaires returned 
by eight large nurserymen. Four claim the Mahaleb to be 
the better root for the sweet cherry and the other four think it 
should not be used. Is it any wonder that our fruit growers are 
making their own observations as to the relative values of the 
different rootstocks? No one is to blame for the existing condi¬ 
tions. We simply lack accurate data. 
Another question asked was, “With reference to pear blight, 
what do you think about the French and Japanese rootstocks l 
Some of the replies received read as follows: 
1. “Prefer the French.” 
2. “We feel that the pear on Jap is a little more suscep¬ 
tible owing to the fact that the tree makes a much 
larger growth.” 
3. “No noticeable difference.” 
4. “Use the French in preference to the Jap.” 
5. “Can see no difference.” 
6. “Neither has any adventage.” 
7. “Japanese is less susceptible.” 
8. “Japanese more resistant.” 
Here again we see differences of opinion. What the correct 
answer is we do not know. No doubt the above replies are based 
on careful observations in the field, but the question can now be 
raised as to the absolute certainty regarding the kind of root- 
stock a certain tree is worked on. A grower may be under the 
impression that his trees are on certain rootstock when in reality 
they are on some other stock. Numerous cases of this nature have 
been called to the writer’s attention during the past year. Here 
again is another neglected phase of the rootstock problem. It 
was only last year that the Division of Pomology undertook the 
problem of determining methods of identifying the different root¬ 
stocks. The deeper we go into the subject of rootstocks the less 
we seem to know. 
The following table gives the percentages of the rootstocks used 
by the nurserymen of the state for the different fruits during the 
years 1917 and 1922. The figures for 1922 represent over nine 
million trees: 
Stock for Almond 
1917 
1922 
Almond . 
. 56.0% 
72.0% 
Peach . 
. 44.0% 
28.0% 
Stock for Cherry 
Mazzard . 
. 71.0% 
80.4% 
Mahaleb . 
. 26.0% 
19.6% 
Others . 
. 3.0% 
.... 
Stock for Pear 
Japanese . 
. 63.0% 
6S.0% 
French .... 
.. 33.0% 
23.4% 
Quince . 
. 4.0% 
6.2% 
Calleryana . 
2.4% 
Stock for Prune 
Myrobalan . 
. 64.3% 
63.8% 
Peach . 
. 23.3% 
25.2% 
Apricot . 
. 1.0% 
1.4% 
Almond . 
. 11.4% 
9.6% 
Stock for Apricot 
Apricot . 
. 57.0% 
46.8% 
Peach . 
. 27.0% 
30.7% 
Myrobalan . 
. 13.0% 
22.5% 
Almond . 
. 3.0% 
Stock for Peach 
Peach . 
. 91.0% 
98.0% 
Almond . 
. 3.0% 
.3% 
Apricot . 
. 3.0% 
1.4% 
Myrobalan . 
. 3.0% 
.3% 
Stock for Plum 
Myrobalan . 
. 60.0% 
57.6% 
Peach . 
. 37.0% 
29.6% 
Apricot . 
10.7% 
Almond . 
. 3.0% 
2.1% 
The above figures bring out some interesting facts. It will 
be noted that the almond root seems to be gaining in favor as a 
stock for the almond. While the demand for the peach root 
for the almond was nearly the same as that for the almond root 
in 1917, it now appears that the peach root is losing its favor. 
The Mazzard root is in greater demand for the cherry now 
than in 1917. This is probably due to the fact that those who 
advocate the Mazzard root have more influence than those who 
stand by the Mahaleb. As was previously mentioned there is 
very little definite information as to the relative merits of each 
root outside of that which has been handed down by tradition. 
There is no doubt in the writer’s mind that there are cherry or¬ 
chards in California on the Mahaleb root where the owner be¬ 
lieves them to be on Mazzard and vice versa. 
Although the French pear root was in greater demand than the 
Japanese root many years ago, it appears to be losing in favor. 
This can possibly be accounted for by the fact that “the French 
root is more susceptible to blight due to its persistent sucker- 
ing.” On the other hand, the Jap root has made a poor record 
in wet soils where the French does well. The quince root is evi¬ 
dently in greater demand now than in 1917. Although no pears 
