1912. 
SWEET POTATO CULTURE. 
Part II. 
PLANTING.—It is advisable not to plant sweet po¬ 
tato sprouts until the ground is well warmed, about 
the time when corn is coming up. In this section 
planting is begun about May 15, and continues to 
about June 25. The plants should be set a little 
deeper in transplanting than they were in the hot¬ 
beds, so that the tender part of the stem shall not be 
exposed. It is best always to water plants when 
setting, unless rain precedes planting, before plants 
show signs of wilting. We use a hand plant setter, 
which does good work, setting plants perfectly erect 
with roots straight downward, watering and cover¬ 
ing, all in one operation. With this planter one man 
can set about 5,000 to 7,000 in 10 hours. Transplant¬ 
ing machines can be used to good advantage where 
large areas are planted, and quantity rather than 
quality of work is considered. When ground is wet 
the trowel is the best implement to use; it is, how¬ 
ever, rarely advisable to set sweet potatoes immedi¬ 
ately after rain, since almost invariably cool weather 
follows, which checks the plant in its most critical 
period of life. Remember the sweet potato is of 
tropical origin, and can stand drought and hot sun¬ 
shine better than a cold rainstorm. Where flea 
beetles or tortoise beetles are troublesome, plants 
should be dropped in a solution of one pound arsenate 
of lead to five to 10 gallons of water. In the hot¬ 
beds plants may be sprayed with the above. The 
critical period of the sweet potato plant ends when 
it begins to send out vigorous vines. It is only im- 
THE RURAL NEW-YORKER 
be dug in damp cloudy weather, especially in loamy 
soil; this does not necessarily affect their keeping 
quality, but mars their appearance, and affects their 
market value. The soil should be dry enough to 
crumble and the tubers exposed to several hours of 
sunshine, whenever possible. Great care should be 
taken not to bruise the tuber, especially if to be stored 
for Winter, as every bruise of the skin leaves an 
HARVESTING SWEET POTATOES. Fig. 136. 
unsightly black scar. The tubers remain attached 
to the stem and are lifted out of the ground, slightly 
shaking them to allow the adhering soil to fall off, 
and laid from two rows onto one. While the clusters 
lie side by side and before any are picked from the 
stem, I personally pass up and down the rows and 
gather my seed, selecting, not single specimens, but 
ideal clusters (see Fig. 136). Hills bearing unshapely, 
overgrown or culls, are rejected, no matter how 
301 
best method is careful selection of seed. In picking 
them from the vines they are laid from two double 
rows onto one, thus four rows are laid together. 
They are now left to dry several' hours, then they 
are carefully laid (not thrown) into crates or baskets 
and carted to the storage room, or shipped to market. 
All culls should be gathered; they make good feed 
for stock; especially hogs thrive and fatten on 
sweet potatoes and make a valuable by-product to 
the grower. geo. h. liepe. 
New Jersey. 
HOW DOES POTATO BLIGHT SPREAD? 
Sometime ago at a farmers’ institute held near here Mr. 
Van Alstyne made the statement that the potato blight 
was carried over in the tuber and this on being planted, 
decayed, the blight spores making their way to the surface 
of the ground were driven on under side of leaf by show¬ 
ers. If this is so, what protection docs a spray give when 
put on top of leaf? It is claimed when the blight once 
gets inside of leaf sprays are useless, as it spreads from 
inside. I have been spraying potatoes for years, and am 
certain it pays, though we sometimes have the blight even 
when tops are well sprayed. I have noticed that on a cer¬ 
tain kind of grayish black soil potatoes almost without 
fail suffer blight about first of August, and this regardless 
of spraying or the kind of manure or fertilizer used. It 
used to be an accepted theory that the blight was bred 
on weeds and bushes and carried by wind to’ potatoes. 
IIow long will it be before this later theory will be ex¬ 
ploded ? Last year a good many of my potatoes on the 
high dry knolls were black inside, sandy soil, and at this 
time some of the potatoes in cellar are putting out sprouts. 
These potatoes upon being cut opon are found to be black 
or with black specks inside. a. s. u. 
Schuylerville, N. Y. 
This is a day of progress. It is true that formerly 
HARVESTING A CROP OF SWEET POTATOES ON A SOUTH JERSEY FARM. Fig. 137. 
mediately after planting that insect enemies are 
troublesome. 
CULTIVATION.—Sweet potatoes require frequent 
cultivation and plenty of hoeing to keep them free 
from weeds until the vines cover the entire field, 
usually requiring about four or five horse cultivations 
and two or three hoeings. A riding cultivator with 
weeder attachment works well where the soil is free 
from trash. By using the riding cultivator often, 
and being careful to go over the rows in the same 
direction each time, they can be worked quite late 
without injuring the vines. Vine lifters on one- 
horse cultivators are also used, but do not work 
satisfactorily under all conditions. Where work has 
not been done in time, and vines have become mat¬ 
ted, they have to be turned by hand or with a smooth 
stick, in order to permit thorough cultivation, and 
destroy all weeds. The old proverb, a stitch in time 
saves nine, applies more truly to sweet potato cul¬ 
ture than to most other crops. Some growers hill 
with cultivator at last cultivation; this, however, is 
not necessary except in very damp soil or to pro¬ 
tect tubers from frost where digging is to be done 
very late. In dry seasons it may even prove injuri¬ 
ous. Rooting of vines it is now generally understood 
will not interfere with the development of the tubers, 
and violent interference with the vines is injurious. 
If, however, weeds are seen rising above the vines 
after cultivation ceases they should be pulled by 
hand, or if close to the plant, cut with at knife or 
other implement. 
HARVESTING.—Where the acreage is small a 
common plow, with the moldboard cut, or broken off 
about half way, so as not to turn the furrow com¬ 
pletely over, but leave the hills so they can be easily 
pulled up by hand, works fairly well; it may be pro¬ 
vided with revolving cutters for cutting the vines. In 
large plantations a special sweet potato plow or scoop 
digger should be used. Sweet potatoes should not 
perfect single specimens may be. From these clusters 
the medium sized (which are best for seed) are 
saved. Every grower has at hand the means to guard 
against deterioration, and improves his stock by care¬ 
ful selection of seed. The writer has bought seed 
from growers and seed houses, which almost in- 
APRIL SCENE IN PENNSYLVANIA. Fig. 138. 
variably was roots and not tubers at all; from some 
of these 1 selected the best, and propagated a few 
plants, but they failed to produce desirable types, and 
after several experiments I have discarded them all, 
and concluded that if one wished improved stock the 
it was supposed the blight spores of potatoes wintered 
in leaves, weeds, etc. Now it is known that the spores 
winter over in the old tubers, and apparently nowhere 
else, as I stated at Bacon Hill. When the soil warms 
up and is full of water these spores multiply very 
fast, some of them naturally come to the surface and 
are more likely to find a lodgement! on the under side 
of the leaf, although not all of them lodge there. If 
it were possible to protect this side of the leaf by 
spray and there was no further infestation from more 
spores coming to the surface, one spraying would en¬ 
tirely protect them. To spray early then, before these 
spores come from the ground, protects the upper side, 
and to some extent the lower side, when the nozzles 
are turned upward, as they should be. It should be 
apparent from the above that if the spraying is de¬ 
layed until this infection takes place it will be much 
more difficult to control the disease, and explains why 
the questioner and others have not always had com¬ 
plete success in spraying for blight. The spores have 
already gained an entrance, and working to the surface 
of the leaf, spread by the wind to other vines and 
fields. If the upper surface is covered there will be 
less danger of infection. It may be possible that the 
trouble on the “grayish black soil” is not blight at all. 
I suggest that some of these leaves be sent to Prof. F. 
C. Stewart, Geneva, or Prof. H. H. Whetzel, Ithaca, 
for examination. I am inclined to think the “black 
specks” referred to are a comparatively new disease. 
Send specimens to either or both of the above named 
professors. I was satisfied at the time that this in¬ 
quirer was not clear as to my statement, and regretted 
that I was compelled to leave for New Jersey before 
I had a chance to talk with him. e. van alstyne 
Prop. H. L. Bolley of North Dakota is working out a 
proposition which may have a great bearing upon western 
farming. Some of the old wheat lands in the Northwest 
are giving smaller yields of wheat. The theory has been 
that this indicates soil failure or loss of plant food. Prof. 
Ilolley’s experiments show that the decreased yields are 
often due to diseases—parasites which cause root rot and 
blight. If this proves true methods will be found to 
combat these diseases and save the yields. 
