286 
THE RURAL NEW-YORKER 
March 28, 
plants; at 1,000 feet, 48 plants. No. 3, at 50 feet, 1,130 
plants; at 400 feet, 600 plants; at 700 feet, 543 plants. 
In these cases the difference in stand appears to have 
resulted from an increasing drying action of the 
wind. On most of the fields, the destructive effects 
of the winds were very evident to the eye, and aug¬ 
mented as the distance from the wind-breaks in¬ 
creased/’ (The italics are mine.) 
HARRY A. MUMPER. 
“BLIGHT-PROOF” POTATOES. 
Why is One More Resistant? 
Some varieties of potatoes are much more resistant 
to “late blight” than others. The Michigan Experi¬ 
ment Station has selected for breeding purposes six 
or seven out of several hundred because they are com¬ 
paratively free from late blight. Why are these 
varieties more resistant than others? The structure 
of the leaf or stem has very little, if anything, to do 
with the ability of the plant to resist blight. Varieties 
with large, thick, leathery foliage are as apt to blight 
as varieties with thin, small foliage. The amount of 
“fuzz” on the plant has nothing to do with it, either. 
Do peaches with a heavy coat of fuzz rot less than 
smooth-skinned varieties? It is thought by some 
that varieties which grow upright are less apt to blight 
than spreading growers, but this is because the foliage 
of the upright growers is more apt to keep dry, and 
so the conditions are less favorable for the growth of 
the disease, not because of any difference in blight- 
II. MIDDLETON AND P. BRITT. Pig. 122. 
resistance. The difference is in the “constitution” of 
the plant, not in its gross structure. 
Now, what do we mean by the “constitution” of 
the plant? The word has been used in a very in¬ 
definite manner, as though it meant something that 
could not be seen or analyzed. It refers to the make¬ 
up of material within the cells of the plant. A po¬ 
tato plant is made out of many millions of cells; 
inside these cells is the protoplasm and other life- 
giving fluids. These are the seat of life; they are the 
real vital force of the plant. This “sap,” as we shall 
call it here, is exceedingly variable in composition, 
not only between different varieties of the same kind 
of plant, as of the potato, but also between different 
plants of the same variety, and even different parts 
of the same plant. You have seen the unstability of 
a piece of mercury, how it is constantly assuming 
new forms, in response to the influence of gravity, and 
heat. You have heard also that the chemical com¬ 
position of Bordeaux Mixture, or the lime-sulphur 
spray, varies greatly according to the length of time 
they have been prepared; that some of the chemical 
compounds in them are breaking up all the time; that 
new chemical combinations are being formed contin¬ 
ually. Yet these are very stable, compared with this 
most elusive of all materials—the “sap” of the plant, 
which is immediately responsive to any and all changes 
in the environment of the plant. This is the chief 
reason why no one has been abje to make protoplasm 
_the life fluid of both plants and animals. When 
the chemist comes to this point he must stop short. 
The composition of this mercurial, ever-changing 
“sap” is what determines whether a variety is sus¬ 
ceptible to disease or not, just as is the case in animals. 
All animals, including human beings, are made of 
cells, and these cells contain life-giving fluids that 
are just as variable in composition as those of plants. 
When a man is “susceptible to grippe” or has .“a con¬ 
sumptive tendency,” there is, as everybody can see, no 
constant difference in the outward appearance to in¬ 
dicate the weakness. The man may be fat or lean, 
black-haired or red-headed, muscular or flabby, and 
so on. The difference, as with the plant, lies in the 
composition of the life-giving fluids within the cells 
of his body. A “good constitution,” then, whether in 
a plant or an animal, means something real and defi¬ 
nite, and is not a generalization. It means that the 
plant or animal is made of cells that contain life fluids 
of such a composition that they are not affected by 
certain germs or other disturbances. 
Naturally enough the next question is whether, in 
breeding disease-resistant plants or animals, one can 
select for a certain definite composition of “sap.” If 
it has been found, for instance, that a variety of 
potato that does not blight has such and such a com¬ 
position, can the potato breeder elsewhere have the 
“sap” of his different varieties or seedlings analyzed 
to see which ones have a similar composition? It is 
claimed that the varieties of pears which are most 
resistant to fire blight—as Kieffer, Seckel and Flemish 
—all have a cell sap of a certain degree of acidity, 
while varieties which blight badly have a different 
degree of acidity. If a man is growing 10,000 pear 
seedlings, (he result of crosses to breed a blight- 
proof pear, may he, then, test the acidity of the sap 
of each of these, while they are mere yearlings, and 
so determine, long before they come into bearing, 
which ones will be “blight-proof?” This is a natural 
inference, but it is not likely that anything will be ac¬ 
complished in this way. 
The materials with which we are working—the pro¬ 
toplasm and other life-giving fluids—are so unstable 
that no chemical analysis would have much value. 
The influence of heredity also makes for uncertainty. 
We must continue to study disease resistance, not by 
chemical analysis, but by the actual behavior of the 
plants in the presence of the disease. It is like the 
problem of fertilizing the soil. Some people never 
cease to wonder why a chemical analysis of a certain 
soil, and a chemical analysis of the crop that they 
wish to grow on that soil, should not, when taken 
together, show what fertilizer will give best results. 
Yet, when the crop is actually growing up -on the 
land, an entirely different kind of fertilizer from the 
one figured out by chemical analysis may prove to be 
best. The only rational way to make fertilizer tests 
is in terms of growing crops, on the land itself; and 
the only practical way of breeding for blight-resist¬ 
ance is to observe the behavior of different plants 
when the disease is present. Disease-resistant varie¬ 
ties of cotton, cow pea, watermelon and several other 
crops have already been developed in this way; a 
“blight-proof” potato is not an impossibility. ' But 
spraying with Bordeaux Mixture will usually give an 
increased yield, much more than sufficient to pay for 
the work, even when there is no blight; because the 
spray stimulates the growth of the leaves and hence 
increases the tuber production also; so I have pretty 
nearly come to the conclusion that a “blight-proof” 
potato would not be an unmixed blessing. 
Michigan. s. w. fletcher. 
AN ONION CROP IN THE SOUTH. 
I wish to set a plot of ground that has a crop of weeds 
and wild onions on same at present to onions. When 
should I fertilize for best resu’ts? In what quantity are 
they crated and where should I sell if I make a success? 
My land is a sandy loam with a clay subsoil and was 
planted to corn last year. M. p. c. 
Sanford, N. C. 
It will take several years to get that land into the 
best condition to grow onions, for no matter how you 
fertilize you cannot take a piece of ordinary farm 
land and make the best truck crop on it till after it 
has been fertilized and improved by a rotation that 
brings in the legume crops like peas to increase 
the humus in the land, and thus make it more mellow 
and retentive of moisture- Black swamp land that 
has been well drained and is abundantly supplied 
with fertilizer suited to the onion crop, will usually 
make the best onions, but any of the level sandy 
land about Jonesboro can be made to produce good 
onions. For selling as ripe onions I believe that the 
Yellow Potato onion will be the best for you, as it 
ripens early and can be put on the market before 
the new onions of the great onion-growing sections 
north come in. This onion is always grown from 
sets planted in the Fall. You can get the sets in 
Richmond, and after once getting a stock it will be 
easy to keep up the supply of sets and to increase, 
for this onion makes no seed, but increases by off¬ 
sets at the root. You can pull and bunch them in early 
Spring, and the markets of Raleigh and Charlotte 
will take a good many; the large ones left to ripen can 
be shipped when ripe. The earliest green onions, how¬ 
ever, are made from sets of what the Norfolk grow¬ 
ers know as Queen onion. It is not the Queen as 
known in the northern trade, but is much better. 
Then you can sow the black seed of some varieties 
and make a better ripe crop by Spring sowing. I have 
found at Raleigh that almost any of the varieties 
of onions grown north will make a good crop from 
the seed the same season, if sown early. The best 
keepers are the Red Wethersfield, Opal, and White 
and Yellow Southport Globe. Seed of these sown in 
late February or very early in March, that is, as 
soon as you can get the land in good condition, will 
make a fair crop of ripe onions in July. The land 
must be well prepared, and not :ss than 1,000 pounds 
of a high-grade fertilizer used, working it in in the 
preparation of the land. A good homemade mixture 
will be 900 pounds of acid phosphate, "29 pounds of 
cotton-seed meal, 100 pounds of nitrate of soda and 
400 pounds of the muriate of potash to make a ton. 
The cleanest possible cultivation must be given the 
crop. Then, after the onions are pulled, sow the 
land in peas to be plowed under in the Fall in pre¬ 
paring for the next season, for it will be better to 
keep the same land in onions for a number of years, 
fertilizing them heavily and growing peas after the 
crop to get the land well stocked with humus-making 
material. In this way you can use fertilizers heavily 
and get increasing crops every year, until peas grow 
so rankly that it will be better to mow them for hay. 
In pulling ripe onions always cure them with the 
DISINFECTING CHAMBER FOR POTATOES. Fig. 123. 
tops on, and store them with the dry tops, as they 
will keep better in this way till wanted for sale. 
Planting sets is an expensive matter, and for the 
ripe crop I would greatly prefer to sow the seed in 
February- The big yellow onions known as Prize- 
taker are best grown by having a cold frame cov¬ 
ered with glass sashes. In this frame you can sow 
the seed in narrow rows in January, and when the 
plants are the size of a small lead pencil can trans¬ 
plant them to the open ground in March, after hard¬ 
ening them off by the gradual removal of the glass. 
These will make very large onions, but they must be 
sold at once, as they are not good keepers. But for 
selling green in early Spring you must plant the sets, 
and it will be better to grow your own sets by sowing 
the seed of the Norfolk Queen in late April very 
thickly in narrow rows and in soil of moderate fer¬ 
tility such as ordinary garden soil. Cure these also 
with the tops attached till ready to use. The fer¬ 
tilizer is applied half in the furrow and half broad¬ 
cast, and beds are made and flattened for setting. 
The sets are planted deeply in the beds and thus pro¬ 
tected till late February, and the soil is then pulled 
away from them so that the bulbs form on the sur¬ 
face with only the roots in the ground. Growing 
good crops of onions is only learned by practice, 
remembering that heavy fertilization is essential, and 
the stocking of the soil with decaying organic matter. 
To grow truck crops of any kind demands that the 
soil be made as rich as possible, and the mere de¬ 
pendence on fertilizers will not do, but you must 
restore the humus that most of your land lacks by 
the annual growing of peas or Crimson clover after 
the truck crops. Then if you want to learn how the 
crops are grown on a large scale you should make 
a trip to the growers about New Berne, where the 
business is carried on on a large scale. You can 
learn a great deal more in this way than by merely 
reading directions, for it would take more space than 
the paper can allow to tell you all about onion grow¬ 
ing. W. F. MASSEY. 
