The Preparation of a Special Light Sodium Fluosilicate and its Use as a Boll Weevil Poison1

Abstract

Two serious objections to the use of commercial sodium fluosilicate as a boll weevil poison are its lack of covering power, due to its comparatively high apparent specific gravity, and its plant toxicity. These have been overcome by incorporating from 10 to 20% colloidal silica with the sodium fluosilicate during the commercial process of manufacture. The resulting special light sodium fluosilicate, containing at least 80% Na22SiF6 causes no economic plant injury and is a quicker weevil killer than commercial calcium arsenate. Under certain field conditions, however, it does not adhere to the plant so well as calcium arsenate. This lack of adherence under extremely moist conditions can probably be overcome by the incorporation of a small amount of adhesive during the process of manufacture. Barium fluosilicate similarly prepared is about as effective as the sodium salt.