WISCONSIN HORTICULTURE 
Treat Cucumber Seed. 
Tests made during the past two 
fit. I years have proved that the angular 
ire I leaf spot disease of cucumbers and 
ig, I probably anthracnose as well arc 
or 1 1 introduced into new fields on the 
rp I seed, says the United States De- 
S partment of Agriculture. Dipping 
the seed in a 1/1000 mercuric 
chloride (corrosive sublimate) so- 
1 lution for five minutes renders the 
e | seed disease-free and has no injur- 
ious effect on germination. Since 
; both diseases overwinter in the soil 
of diseased fields, however, it is 
highly important not to plant in 
fields which were in cucumbers the 
preceding season, 
treatment of cucumber seed can 
I be done most advantageously by 
seedsmen and pickle companies be- 
fore the seed is distributed to their 
glowers. It is a relatively simple 
operation and can be easily done in 
the storage houses if running wat- 
er is at hand. 
Metal containers cannot be used 
for the mercuric solution. The 
highly poisonous nature of this 
substance should be kept in mind. 
Purchase mercuric chloride on the 
basis of one pound to every 500 
pounds of seed to be treated. 
Make up a concentrated stock so- 
lution of a strength of 1/20 by dis- 
solving one pound in two and one- 
half gallons of water. This stock 
solution is diluted to 1/1000 by 
adding one quart to twelve and 
one-quarter gallons of water. Stir 
thoroughly. For the treatment 
use a barrel, wooden tub, or large 
crock. 
How to Treat Seed. 
Place the seed in burlap or 
cheesecloth bags, fifty pounds in 
each bag. The bags should not be 
over three-quarters full to allow 
for swelling of the seed and to 
facilitate stirring. Immerse the 
bag of seed in twelve and one-half 
gallons of the 1/1000 bichloride 
solution and agitate vigorously 
with a stick to secure thorough 
wetting of the seed. Remove the 
bag promptly at the end of five 
minutes. Immerse at once in a 
barrel of running water and stir 
thoroughly. Wash about fifteen 
minutes. Dry the seed as rapidly 
as possible. Forced drying bv a 
centrifugal machine or an air blast 
is much to be desired. 
The bichloride solution should 
be used only once since its strength 
is greatly decreased. Make up a 
fresh dilution from the stock so- 
lution for every bag of seed. 
To treat seed in smaller quanti- 
ties dissolve one tablet of mercuric 
chloride in one pint of water for 
each half pound of seed. 
Guard against reinfection of the 
treated seed. Bags to be used for 
treated seed should be soaked in 
the 1/1000 bichloride solution for 
at least five minutes, rinsed, and 
dried. Solution used once for 
seed may be used for this purpose. 
Growers should not plant cucum- 
bers in the same fields used in 1917 
for cucumbers, watermelons, or 
cantaloupes, or on land imme- 
diately adjacent to such fields. 
As far as possible, the depart- 
ment will undertake to send a rep- 
resentative to supervise the treat- 
ment of the seed where large quan- 
tities are involved. 
Crown Gall on Young Apple 
Trees. 
S. B. Fracker, Assistant State 
Entomologist. 
The disease called Crown Gall 
ma y found on apple nursery 
stock in the form of large lumps 
or knots on the crown and roots 
of the trees or in smaller lumps 
liom which arise a large number 
of long, fine, thread-like roots. 
I he latter form is known as 
“hairy root”, but it is caused by 
the same bacteria as are respon- 
sible for the galls. This disease 
has long been recognized to be 
very injurious in the western irri- 
gated orchards, but many nursery- 
men have claimed that it does lit- 
tle damage to trees in this part of 
the United States. The fact that 
an infected tree will survive and 
bear fruit, seems to be the prin- 
cipal basis for their claim, as it is 
often difficult to tell how much a 
tree is weakened by a disease or 
pest. 
The writer made some observa- 
tions on nursery-grown trees this 
fall in order to find out what ef- 
fect the crown gall had on the 
young stock. It was found that 
in every nursery visited a much 
higher percentage of infected 
trees had to be thrown into the 
cull pile on account of small size 
and weak growth, than was the 
case with healthy trees. This was 
true of every variety examined. 
It appears from the results that 
the presence of galls or “hairy 
root ’ reduces the strength and 
size of the tree during its nursery 
life from 15 to 25 per cent. We 
are safe in drawing the conclusion 
therefore, that this reduction in 
the value and strength of the tree 
will be continued after the tree is 
transplanted into the orchard. 
Buyers of nursery stock are 
warned to watch for infected 
trees, especially on material from 
nurseries outside the state, as it is 
not lawful to deliver these trees 
to customers. In case of doubt, 
send samples to the State Ento- 
mologist at the State Capitol who 
will appreciate any information 
sent in. S. B. Fracker, 
Assistant State Entomologist. 
