The use of arsenical compounds in the control of deep-rooted perennial weeds

does not appear. First page follows. As chemical weed control becomes more generally practiced, the limitations as well as the possibilities of the various methods become more evident. The effectiveness of these methods depends upon certain factors which must be carefully considered if consistent results are to be obtained. Many of the factors may be controlled by the operator. It is, therefore, essential to the successful practice of any new method that a descriptive study of the more readily controlled factors be made; for only when we understand the underlying principles may we obtain the best results. This preliminary report describes the preparation and use of an arsenical solution recently employed with considerable success in controlling deep-rooted perennial weeds. It discusses the mechanism involved in the movement of the arsenical solution into the roots of plants, and submits data for comparing and evaluating the factors that tend to limit its action. It discusses also the conditions essential to successful practice and gives certain precautions for the handling of the reagents. One should understand at the outset that the arsenical herbicide described in the following pages will not completely eradicate perennial weeds. Such results cannot be expected of any chemical weed killer. This herbicide has, however, proved very satisfactory when prepared properly and applied under optimum conditions.