The Delta independent., 1913-10-17

rapid and vigorous termination would
ordinarily be assured.
In some instances the stems and
roots of potato vines were blackened
from the cuttings upwards, while the
leaves of such plants were yellow and
curled upwards. In these instances it
is probable that the diseases was one
known as "black-leg." No treatment is
known which will check or cure thsse
lem rots, because the affected por-
( tens are underground.
| 1t is advised that at this time thu,
pc tato grower go carefully over his
fields and dig out all vines seen to be
affected with these diseases. They
81 ould then be carried eff and burned
Il the farmer is unable to do this with
hi; entire crop, he should rogue" that
portion of it intended FOR seed purpos-
es, and this should be his choicest plat.
Many striking object lessons were
presented in fields visited during the
earlier part of the present month on
THE value of care in seed selection also
on the bad effect of planting potatoes
successfully in the same fields.
The powdery or dry rot fungus most
ly gains entrance through cuts and
bruises in the skin of stored potatoes.
Here we have ample evidence of the
presence of the disease and of injuries
to the skin of the potatoes in great
abundance. There is an intimate rela.
ton between the two. 1t is a pity that
the writer may not reproduce in this
paper photographs showing to what
extent disease has gained entrance at
the site of wounds; such pictures
would be more impressive than words
Different portions of a large field
owned by well known potato grower
had been subjected to varying rotation
and planted respectively with selected
and unsolicited seed potatoes. These
will be designated as plats l. and 3
Plat l: Three years in potatoes. one
year in oats, then in potatoes in 1913.
ISeed not selected. Owner has noted
Rhizoctonia stem rot in previous sea
sons to some extent. BY actual count
20 per cent fothe vines in this plat
were visibly affected with stem rot.
An examination of the roots of appar
emily healthy vines shove dmany of
these also to be more or less infected.
1t would be conservative to estimate
that 40 to so per cent of the vines had
been attacked by Rhizoctonia. There
were Is per cent of missing hills,
mostly due to planting diseased cut
tings.
Plat 2. Ten years in alfalfa. year
in grain, then potatoes in 1913. In
this plat per cent of the vines were
visibly affected with stem rot; about
10 to Is per cent of the hills were
missing on account of diseased cut
ltings.
Plat 3. Same kind of lanl adm ro-
tation as plat No. 1, but the seed was
taken from rarefully selected potatoes.
weighing from to 10 ounces, and cut
into four pieces. Only 3 per cent of
these vines were visibly affected, the
gaps were few, the vines uniform and
perceptibly larger and more vigorous
than the others
In the field of another grower whose
seed had not been selected or treated
40 per cent of the vines were visibly
affected with stem rot. both Rhizoc-
tonia and "black-leg," and all were
puny. In addition to this, about 30
per cent of the cuttings had failed to
sprout at all on account of bad dry
rot infection. The whole field was
poses. marketing or storage. In vary
ing degrees these lessons were repeat
ed as other fields were inspected.
An inspiring sight for any farmer in
the state was 100 acre field of splen-
didly uniform, vigorous potato vines,
then almost meeting between the
rows. This field was planted with
carefully selected, clean seed. 1t re-
minded the visitor of some of the best
Scotch and English fields from which
enormous yields are obtained.
1t Is true of plant. as well as of ami
NAL diseases. that sanitary measures
are among the best safeguards. A
thorough cellar-cleaning and dsinfect-
ing is therefore in order now In the
dust and trash lying on floors and in
every nook and Granny of potato eel
lars in this state lodge innumerable po-
tato disease germs which, unless re-
moved or destroyed may and probably
viii attack the new crop placed there
during the coming harvest.
Sorter injuries are perhaps the most
common. These are crescent shaped