Vol. LVII. No. 2504. 
NEW YORK, JANUARY 22, 1898. 
*1 PER YEAR. 
THE GROWING OF UN BLIGHTED POTATOES. 
SUCCESS WITH A I.ATK-PLANTED CROP. 
Difference Between “Blight” and “Rot.” 
My first experience with potato diseases was about 
15 years ago, when I first commenced to farm for my¬ 
self. After raising a good crop of about 200 bushels 
per acre, and losing about half by rot, 1 remember put¬ 
ting 90 bushels in the barn cellar, of which, when taken 
out in a few weeks, about half were rotten. This was 
my first and last experience with the Potato rot 
(Phytophthora infestans). For four years after this, I 
made a sort of specialty of growing potatoes, growing 
each year nearly 10 acres, but to do my level best, I 
could not get over 100 bushels per acre, and sometimes, 
less than that. The land was not poor, for the wheat 
crop, for the four years after the potatoes, averaged 
about 38 bushels per acre ; one year, it went over 41 
bushels. The potatoes were put in in good shape, 
given good cultivation, and the stand was good. They 
would start off well, and grow thriftily until about the 
middle of June, 
when they 
would stop 
growing a n d 
commence t o 
die down, and 
by August 1, 
would be all 
dead. I came 
to the conclu¬ 
sion that it was 
not all my 
fault, that some 
disease was the 
cause of it, and 
called it blight 
for short, be¬ 
cause I didn’t 
know what else 
to call it. 
My losses on 
the potato crop 
discouraged me 
so with farming 
that, having a 
chance to work 
for the Experi¬ 
ment Station at 
Columbus, O., I 
left the farm ; 
but the subject 
of Potato blight 
was ever with 
me. Spraying 
was just][ com¬ 
ing into practice, and I well remember the work of 
Prof. C. M. Weed, and hoped that a remedy would be 
found; but after watching ’t several seasons, I found 
it was only a partial remedy at best. About Colum¬ 
bus, the blight was exceedinglj r severe, so much so 
that the tubers would be affected by a dark ring just 
under the skin at the stem end ; this I noticed in about 
1890, also that the vitality of the tuber was badly 
affected. I think that there is but little doubt that 
the disease is carried from one season to the other in 
the tubers. 
Noticing the fact that the greatest harm was done 
in hot weather, and when the plant was making the 
last half of its growth, I came to the conclusion that 
late planting would help matters, for the last part of 
the growth would necessarily be during the cooler 
weather. While carrying on an experiment in late 
planting during the season of 1895, I became aware of 
the extremely contagious character of the disease. I 
watched the blight spread from an early field where it 
had done but little damage on account of the advanced 
growth of the vines, on to the late-planted ones grow¬ 
ing alongside, which it practically ruined, then to 
those farther away, where the damage was still less, 
and still later, on to another small patch where almost 
no harm was done, and a good yield was secured. 
While preparing the seed for this experiment, I came 
across several facts that made me long for a chance to 
try an experiment where isolation and unblighted seed 
should be the main features. Hut I was not permit¬ 
ted to do so until the past summer, and had I had the 
making of the conditions, I could not have made them 
more favorable. 
On a small farm, I found that I had a small field of 
very poor land that had not, in all probability, grown 
potatoes for years. My work up to July 1, was for 
Mr. A. I. Root, who had about 3,000 bushels of seed 
potatoes for sale, and while working with and watch¬ 
ing the sprouting of these, I was able to see that, tak¬ 
ing those grown in the later part of the season, I 
could get unblighted seed at small cost. My first 
choice would have been the Rural New-Yorker No. 2, 
but I could get but few of these, so 1 had to take the 
Sir William. 
Giving my seed a special preparation, 1 planted the 
first week in July. The weather during July and 
August was much more favorable for the growth of 
potatoes than usual, and I made the most of it; with 
the use of Breed’s weeder, I kept the ground almost 
perfectly clean. 
Commencing in the latter part of August, and con¬ 
tinuing through September, was a drought of unusual 
severity; the roads were deep with dust, water was 
hauled for stock, and brooks were dry. But my little 
potato field kept green and growing in a manner that 
astonished the natives. Had there been any start for 
the blight, I am certain that it would have had 
weather that was extremely favorable for its develop¬ 
ment. But the vines kept growing and green until 
the middle of October. When the picture shown at 
Fig. 16 was taken October 7, they had commenced 
ripening ; the foliage, instead of turning directly from 
the green to brown, went through a yellow stage, as 
do the leaves on our forest trees. This I believe to be 
one of the most certain signs of freedom from blight. 
The yield was not large, about 125 bushels per acre, 
on the part shown in the picture. Considering the 
condition of the land, a large yield could hardly have 
been expected. The soil was an impervious clay that 
had been tilled by non-resident renters for the past 
eight years. A more forbidding field would have 
been hard to find than this was last spring. 1 realized 
the poverty of the soil, and planted the rows of pota¬ 
toes 334 feet apart and two feet apart in the row. Had 
a heavy application of good commercial fertilizer been 
given, and the potatoes planted closer, the yield would 
have been much larger, no doubt. But I am satisfied 
that I got about as large a yield of potatoes as the 
soil was capable of giving. This, l believe, is saying 
more than those could say who planted earlier. 
That there are two diseases that are very destructive 
to potatoes, is a fact that most scientific men who 
have studied the subject, are agreed upon—the rot 
which destroys the tubers after they are formed and 
full grown, and 
the blight 
which does its 
work on the 
vines before 
and while the 
tubers are 
forming. I be¬ 
lieve that the 
larger part is 
due to some 
form of bacte¬ 
rial disease,and 
that the blight 
can be best pre- 
vented in a 
manner similar 
to that which 
doctors use in 
the prevention 
o f contagious 
diseases, except 
that we shall 
have to isolate 
the well ones 
from the sick, 
and keep our 
seed unblight¬ 
ed. The indis- 
criminate 
growing of a 
large number 
of varieties to¬ 
gether, as well 
as the growing 
of early and late varieties in close proximity, will, no 
doubt, do much to keep the disease with us. 
There seems to be an indiscriminate use of the words 
“blight” and “rot”, which, I think, is due to the 
fact that these diseases are not clearly defined as yet. 
in the eastern States, as far as I have been able to 
learn, the rot has been quite prevalent during the past 
year; but in Ohio, as well as some of the western 
States, blight is known. Prof. Jones of Vermont was 
one of the first to recognize it. Here blight is bad, 
and for 15 years, I have not seen a genuine case of rot. 
This, I think, is due to the fact that the blight has 
crowded the rot out. Coming before the rot, it leaves 
nothing for the latter to work upon. When we have 
the rot, we get our crop and lose half of it; when we 
have the blight, we lose half of it before we get it, if 
that is possible. In the latter case, we are saved the 
expense of harvesting, and it is certainly discourag¬ 
ing, as well as unprofitable, to harvest a crop of pota¬ 
toes, and then lose the larger part of them by rot. 
Ohio E. C. GREEN. 
