NINTH ANNUAL YEAR BOOK— PART V 201 
soon spreads the weed over the field. Mr. E. J. Gumbert, of "Walnut, Iowa 
gives his method as follows: 
The land was given a shallow plowing late in the fall of 1906. In the 
early spring of 1907 it was disced as soon as the frost was out of the 
ground and then kept the cultivator and harrow on it nearly every week 
until about the 20th of May, then it was plowed deeper than before, then 
disced and harrowed and planted to corn, then cross harrowed and the 
corn plowed five times, sowing rape before the last cultivation. The 
corn was cut in September and the ground plowed late in the fall and 
again in the spring of 1908, harrowed and planted corn on the 20th of 
May and harrowed twice. 
Tarred paper can be used to advantage on a small patch. The edges 
of the paper should overlap and the edges covered with earth. The Quack 
Grass should be covered at least six months. When the land is badly 
infested it may be a good plan to summer fallow. The land should be 
plowed, harrowed to expose the roots to the sun, then disc. This method 
of discing and harrowing every week is a good one and by the end of the 
season little Quack Grass will remain. This weed will not prove trouble- 
some where deep plowing is resorted to. 
Canada Thistle. The Canada Thistle can be treated with sodium arse- 
nite according to Professor Bolley. No other chemicals, so far as our 
experiments extend, are efficacious in entirely destroying this weed. Car- 
bolic acid only partially destroj^s the roots and the plants shoot up again 
from below the point of injury, but by repeating the process the Canada 
Thistle can ultimately be exterminated. A good method to eradicate the 
weed is to plow shallow and cultivate frequently during the summer. 
The roots of the Canada Thistle extend deeply down into the soil, hence 
for this reason deep cultiviation will be of no avail. After turning the 
soil over after plowing, the soil should be dragged and the roots exposed 
to the sun and removed, when possible. It may be necessary to run over 
the field with a hoe and to watch the stray plants which appear. This 
method was tried on a patch several years ago and no Canada Thistles 
have since made their appearance in this place. Various crops, such as 
clover and sorghum are said to be efficacious in subduing the thistles. 
The treatment generally recommended by the persons sending replies 
in answer to the circular, is thorough cultivation. Give shallow plowing, 
deep plowing will be of no avail because the roots sprout twelve to fif- 
teen inches below the surface of the ground. The land should be thor- 
oughly disced, harrowed, and then cultivated and any plants appearing 
should be cut with a hoe. V/here the patch is not a large one it would be 
better to summer fallow. The weed has been held in check to a con- 
siderable extent in some portions of the East by means of a fungus which 
is parasitic upon the leaves. Tarred paper has been used with success. 
Carbolic acid is not as effective as sodium arsenite, but sodium arsenite 
is rather dangerous to use especially if cattle have access to any part of 
the plot where the weeds grow and application is made. Salt has proved 
successful where it is applied in considerable amounts around the roots 
of the plant and cattle and sheep are given access to it. 
Morning Glory. Morning Glory is not as pernicious in its character as 
Canada Thistle, Quack Grass, or Horse Nettle. The best treatment that 
