Vol. LXXI. No. 4140. 
NEW YORK, MARCH 2, 1912. 
WEEKLY, $1.00 PER YEAR 
DOES IT PAY TO MIX VARIETIES IN 
PLANTING AN ORCHARD? 
Would Mr. Van Deman toll us something definite about 
the necessity of setting different varieties of fruit, es¬ 
pecially apples, together to fertilize the blossoms better? 
Some authorities say set each variety in a block by itself, 
and some say to mix them. If anybody ever saw a large 
orchard of any variety actually improved by grafting or 
setting in another variety to mix the pollen, why can't we 
know about it? All the advice I can find is rather in¬ 
definite; they seem to guess at it. It would be something 
very valuable if you could get definite reports on a large 
number of standard varie¬ 
ties whether there is ever 
any real improvement in 
yield by mixing varieties, 
and how close to set them, 
etc. c. l. T. 
Ilarwick Seminary, N. Y. 
The subject of the 
cross-pollination of or¬ 
chard fruits is one of the 
most practical and living 
ones that we have before 
us to-day. There is 
scarcely any fruit that it 
does not concern. The 
pollination of the flowers 
of date trees has been 
known and practiced by 
those who have culti¬ 
vated them for many 
ages past, and there is, 
perhaps, not a pound of 
dates in any of the mar¬ 
kets of the world that 
was not produced by 
artificial means. The 
choicest figs of Turkey 
are also the product of 
the art of pollination by 
the hand of man. Our 
cultivated strawber r i e s 
are largely of such na¬ 
ture as to need planting 
with a view to the flow¬ 
ers of the different va¬ 
rieties crossing their pol 
len one upon the other 
to increase their fruitful¬ 
ness, and some of them 
are absolutely dependent 
upon it. Since the days 
of the seedling orchards 
when there were almost 
numberless varieties, and 
always many of them in 
the same orchard, and 
when we now have large 
blocks of one variety, the 
need of accurate knowl¬ 
edge of the peculiarities of the floral organs is essen¬ 
tial to the best success. We must also know which 
are self-pollinating and which are not. And we must 
know, if we are to attain the best results, which are 
effective one upon the other. This is a theme upon 
which but little has been written, and still less really 
known. Guessing really counts for nothing in the 
matter of cross-pollination, and there is remarkably 
little definite experimentation upon which to base 
specific knowledge and which may be used as a safe 
guide to the orchardist. However, there are some 
things about the potency and impotency of pollen and 
the receptivity of the female organs of some trees that 
we do know, although it is more of a negative than 
M of a positive character. Every experimental hybrid¬ 
izer quickly learns that the laws governing his work 
cannot as yet be tabulated with any certainty; there is 
^ still some unknown quantity behind. 
Scientific pomologists and private experimenters 
f, have been long doing a little in the way of crossing 
>® the varieties when in bloom and saving the seeds for 
’ r planting to grow seedlings. Some of the results of 
j these experiments have been of great value to the 
g cause of practical fruit growing, but much more has 
been a disappointment to the toiling experimenters, 
i- and unfruitful of any real good to the horticultural 
h world. When the National Government and the States 
st entered upon the establishment of agricultural experi- 
•e ment stations some 25 years ago the opportunity for 
n doing this public work at public expense was pre- 
v sented. and it was not long until orchards were 
te planted expressly for experimental purposes. Men of 
y scientific training were placed in charge and means 
;e furnished them to go forward and do some of the 
r e things that had long been needed. It took not only 
ic knowledge and money but time to grow trees to a 
d stage where their flowers could be studied and used in 
it experiments. There were older orchards in the hands 
n of private fruit growers which were gladly placed at 
the disposal of the scientists, and these have been used 
also to help work out the problems that have puzzled 
all of us for many years past. The little that was 
definitely known about the self-fertility and self¬ 
sterility of varieties was, as has already been said, 
more of what we could not do than what we could 
do in the successful production of fruit. We knew 
that the Wild Goose plum was often very unfruitful, 
but just what we might do to make it fruitful was 
largely a mystery. We knew that the Bartlett pear 
when planted in large blocks often bore indifferently, 
but why and how to 
change its habits we could 
only guess. Within the 
easy recollection of manv 
of us these problems 
have been solved by dig¬ 
ging out the fundamen¬ 
tal, scientific reasons. 
There is no doubt that 
there are many causes 
for the unfruitfulncss of 
our fruits, such as kill¬ 
ing or weakening the 
fruit buds by severe 
Winter weather, Spring 
frosts, excessive rains at 
blooming time, the at¬ 
tacks of fungus diseases 
upon the floral organs 
when in bloom, and 
sometimes spraying when 
they are in this delicate 
condition, but their own 
inability to fertilize their 
oyules is the main caus: 
of the trouble with some 
varieties. To determine 
which they are and also 
those that are independ¬ 
ent within themselves is 
the main problem to be 
solved. Failure to polli¬ 
nate is not constant or 
alike on the same tree or 
variety every year. Cli¬ 
matic conditions or lack 
of nourishment and vigor 
may change the setting 
or budding of the fruit. 
During untold ages na¬ 
ture has been crossing 
and recrossing her 
species of plants, both 
within and without the 
specific limits, and with 
all manner of results, 
but mostly with surpass¬ 
ing success in reproduc¬ 
tion and the perpetuation of the species. They have 
been inbred and yet crossbred. It has thus been the 
propagation of the like and the unlike. Thorough¬ 
breds and hybrids have been multiplied and created 
at the wild will of the winds and the insect agencies 
of nature’s own providing. Fully a century ago 
Sprengel observed and published these facts to the 
world and later Andrew Knight did the same thing. 
But Darwin was the first forcibly to present the fact 
that nature demanded the opportunity to intermix the 
pollen of the individuals of the same species to pre¬ 
serve the virility and productiveness of that species 
and that she abhors continued self-pollination. His 
doctrine of “the survival of the fittest” was as true 
