It can now be said with certainty that such a discovery has been made. The first successful experiments were attempted in June, 1906, by the Agricultural College of the University of Wisconsin. The work has been carried on under the direction of Professor R. A. Moore. It should be recalled that the University of Wisconsin has already established a wide reputation for itself. The Babcock milk test which has saved more to the farmers of Wisconsin than the cost of the whole university from its foundation to the present time, resulted from experiments at the Wisconsin Agricultural College. The formaldehyde treatment for smut in grain is also one of the successful discoveries of the same

many where experiments had been tried on mustard. Plans were laid to make tests on the University farm as soon as the wild mustard appeared. No machine for the purpose is made in this country. A sprayer costing $135 was imported from Germany. The tests on the University farm were entirely successful. Professor Moore then experimented on other Wisconsin farms, in Dane, Kenosha and Waukesha counties and at Lynn, Lyons county, Minnesota. As far as known these are the only experiments that have yet been made in this country and in every case there is evidence that the weeds have been annihilated while there has been no perceptible injury to the grain. The grains that have been

tested are oats, barley, wheat and spelz. No tests have been made on rye in the United States, but Professor Staglich has had success in spraying rye in Europe. Experiments are also being made on Indian corn and the results so far have been successful. The only effect that is seen on the grain is the blackening of the lower and older leaves that are doomed to wither eventually, while the young leaves, that bring the cereal to maturity, are unharmed. There are no complaints from any center of deterioration either in the quality or quantity of the grain crop sprayed. There has been no difference observed in the time of ripening. No tests have been made in this country on clover or grasses but experiments made in Scotland show that in no case was damage done to the young clover or grass while the mustard was entirely destroyed.

So far, the sulphate of iron solution. is found to act definitely on mustard, yellow dock, cockle bur, smart weed, rag weed, and Spanish needles while there is

every reason to believe that it will destroy Canada thistle. Professor Moore says, "A sprayer of German make was recently shipped to the college for use in this investigation and I believe that it will mean the redemption of much land now infested with noxious weeds. Canada thistles can eventually be killed off, too, but as they are perennials, sending up new heads from the root, they must be treated several times during successive seasons. Experiments along this line are now being carried on by the station, but definite results cannot be obtained until another year shows whether the thistle roots are killed, as we hope, by the frequent blighting of the tops."

It is at once apparent that every section of the country will share in the benefit of this discovery. The various weeds that iron sulphate will destroy are found to prevail in different localities. The white daisy is familiar to eastern farmers, the rosin weed to western, wild mustard is widely scattered and Canada thistle grows in most of the northern states.

By means of the various tests carried on it is now pretty well established that the best time for spraying grain field infected with mustard is when the mustard plants are in the third leaf. If done before this there is risk of some seed germinating after the operation which would. make a second spraying necessary. If delayed on the other hand until the flower buds are formed the spraying checks but does not entirely destroy the weed and seed may be formed. In the Wisconsin experiment, however, mustard twenty-six inches high was destroyed with one spraying. The best results are obtained when the plants are taken in the younger stage. It is the opinion of English authorities that if the mustard is sprayed after the stems and flowers are formed that though the leaves are destroyed the stems and flowers retain sufficient vitality to form seeds, the number of which is much less than in the case of a plant in the normal condition. The principle acted upon is to prevent the mustard from forming flowers and seed. The stock of seed in the ground will then be used up in the course of time and if no further seeding takes place, the pest will be completely gotten rid of. The time for making the test is of extreme importance. The condition of the weather is a factor to be considered. The day must be bright and sunshiny. There must be no wind and the dew should have evaporated. If rain follows the spraying within. a few hours the solution will be weakened and the mustard will not be successfully exterminated. If rain follows sixteen hours after the spraying the extermination will be quite perfect. In a case of rain two hours after, fifty per cent of the mustard lived to produce seed.

Two days after the spraying all that can be found of the mustard is a black powder where the plant stood. Very little damage is done to

the grain crop by driving over it at this time of the year. In the test made, strips were left unsprayed in the center of the grain fields to prove the effectiveness of the experiments. After two days the strip stood out distinct with its yellow blossoms. Where the spraying was done not a live plant could be found.

The sprayer used for the tests has the appearance of a chemical fire engine but for the fact that the large copper tank which holds seventy-five gallons of solution is mounted on a two wheel cart and is drawn by one horse. Pipes filled with numerous holes extend like arms ten feet from each side of the machine. A fog like spray is spread over the field from these pipes. A pump is set in motion by the drawing of the machine. This keeps a pressure of one hundred pounds on the liquid. The arms of the machine can be adjusted so that the spray is brought close to the crop or in case of narrow places the arms can be raised perpendicularly. Care is taken to prevent foreign material from gaining entrance to the reservoir. The solution before using is strained through a fine wire sieve.

To spray one acre of grain requires about one hundred pounds of iron sulphate dissolved in fifty-four gallons of water. The sulphate of iron is a bluish powder and resembles granulated sugar.

WILD MUSTARD.

WILD MUSTARD.

One Wisconsin farmer who owns a farm of 400 acres had 200 acres that was infested with wild mustard. An oat field containing twenty acres was cleaned of mustard for him. He said that

he considered that $25 was added thereby to every acre he owned. From 15 to 20 acres can

be easily sprayed in a day.

A good deal has been said by chemists as to the comparative values of sulphate of copper and sulphate of iron for the purpose of spraying. Sulphate of iron is less in cost and has the added value that it acts as a stimulant to the cereals and fertilizes the soil. English authorities have noted the more lively green of grain that has been sprayed with sulphate of iron. This gives a double value to the process of spraying. Agriculturists everywhere confront the experimenter with the question as to why the weed is killed and the cereal left uninjured. Various theories have been offered. It is a botanical question of much interest. It is found that sulphate of iron sprayed on turnips will produce serious effects. Turnips belong to the same order as mustard. One theory of the difference in effect is that it is due to the varying quantities of oil in plants. This has now been disproved by Professor Stender of Breslau. A second theory held that the difference in effect arose from the position of the leaves, whether more or less vertical, but this has no apparent foundation. Still another argument advanced is that the roughness of the leaves produces the difference in the results. The rough mus

It dissolves readily in water and in five or ten minutes has gone into solution. It is not poisonous, so will not injure stock. One man can do the work of spraying.

The cost of spraying an acre of grain is such as to make it entirely practical. The sulphate of iron costs fifty-five cents per acre. The cost of labor is estimated at twenty cents, making a total of seventyfive cents per acre. The opinion of the farmers as to this cost will afford the best criterion by which to judge as to the feasibility of the use of the solution.

tard leaves were thought to retain the spray better and therefore to feel the full effects of the solution. This theory also is untenable for there are many other plants that retain the spray equally well and yet escape injury. It is probable that the plants injured contain substances peculiar to the order, substances which react chemically with the iron salts. This subject is being investigated by Mr. Ingles, agricultural chemist of Yorkshire College, England, and has been extensively discussed by Professor Stender, of Bresleau.

The farmers of Wisconsin consider this plan of weed destruction a pronounced success. C. O. Perkins of Muk

wanago, directly after the crop was harvested from the field where the experiment was tried, wrote, "The experiment for killing mustard was a success. When I harvested the grain I could not find. a straw of mustard, and no mustard came up in the stubble after the grain was cut, as it usually does. I also think it prevented my oats from being infected with rust. The fields on both sides were troubled badly with rust, but none appeared in the field sprayed."

All indications seem to show that this discovery will go far towards making easier the farmer's lot as well as greatly increase the yield of cereals.

-Whittier.