UNITED STATES PATENT OFFICE 2,277,744 PEST CONTROL Martin E
Total Page：16
File Type：pdf, Size：1020Kb
Patented Mar. 31, 1942 2,277,744 UNITED STATES PATENT OFFICE 2,277,744 PEST CONTROL Martin E. Cupery and Arthur P. Tanberg, Wil mington, Del, assignors to E. I. du Pont de Nemours & Company, Wilmington, Del, a cor poration of Delaware No Drawing. Application August 15, 1940, Serial No. 352,812 6 (Claims. (C. 6-45) This invention relates to pest control and is or the operator's clothing impregnated therewith particularly directed to methods and composi is actually more resistant to combustion that if tions for the control of Weeds, that is to Say, it Were not so treated. The other sulfamates economically harmful chlorophyl-bearing plants, have a fireproofing action also, though not to which are characterized in that the active phyto the extent of ammonium sulfamate. None of cidal principle is a sulfamate. them present the fire hazard of the chlorates. The control of weeds whether annual, biennial In addition to ammonium sulfamate, sulfamic or perennial, or woody or Succulent, by means of acid and the metallic derivatives of sulfamic acid chemicals is becoming increasingly important, We may use the organic ammonium derivatives, but the advance in this art is limited' by the 0. that is, the amine Salts of sulfamic acid. Thus limitations of materials available for this pur We may use Salts derived from the mono-, di pose. Thus, of the more common Weed killers the and tri- methyl, ethyl, and ethanol amines; do chlorates, including sodium and calcium chlorate, decylamine and the amines derived from coco oils and carbon bisulfide involve dangerous fire nut Oil alcohols known commercially as "Lorol' hazards, Sodium arsenite, ammonium thiocya 5 amine; and ethylene diamine, hexamethylene nate and carbon bisulfide are highly poisonous diamine, and other polyamines such as diethylene materials or are otherwise objectionable. Long triamine and triethylene tetramine. These amine time soil sterilization is also a problem encoun SaltS may suitably be used in combination with tered with some weed killers, particularly soluble ammonium sulfamate. arsenicals, oils and various soluble salts, unless 20 The sulfamates, including sulfamic acid, may proper precautions in application are taken. be applied simply from aqueous solution and may Other weed killers such as sulfuric acid whether also be applied With certain advantages in com used alone or combined with soluble arsenicals bination with a hygroscopic agent such as cal are highly corrosive to equipment and difficult cium chloride, Zinc chloride, glyceryl ammonium to handle. Still other weed killers are Selective 25 Sulfate, glycerol, Sorbitol, glucamine, glycol and in their action and many cause only wilting of diethylene glycol ethers, ammonium thiocyanate, foliage on woody plants without any permanent polyvinyl alcohol, and other water-miscible or killing back of the Woody structure. ganic Substances of high molecular weight such We have now found that effective chemical as polyglycols, polyclycerols, (polyethanoxy) control of a wide variety of Weeds including that 30 glycerols and their ether, ester and amine deriva pestiferous Woody perennial, poison ivy, can be tives, and in general substances of the character obtained by the application of a sulfamate to the described in U. S. Patent 2,144,647 granted Jan foliage. By spraying the foliage of the Weeds uary 24, 1939, as well as substances of the char. with an aqueous solution of sulfamate, especially acter set forth in French Patent 845,388. ammonium sulfamate, we are able effectively to Wetting agents may also be included. Sodium control a wide variety of Weeds without the dis lauryl sulfate, sodium salts of alkyl naphthalene advantages characteristic of the prior art weed Sulfonic acids, long-chain C- or N-substituted killers. betaines, long-chain quaternary ammonium salts, While various sulfamates, including Sulfamic Salts of long-chain aliphatic secondary sulfonic acid (hydrogen sulfamate), sodium sulfamate, 40 acids such as those described in U. S. Patent potassium sulfamate, and the like, may be used 1,242,162, Sodium salts of alkyl sulfonic acids de in the compositions and processes of our inven trived from petroleum as described in U. S. Patent; tion, ammonium sulfamate has been found to 2,197,800 and like wetting agents may be em possess the more desirable combination of prop ployed. erties useful in Weed control. Ammonium Sulfa 45 The Sulfamates may also be used in conjunc mate is highly soluble in water and may be easily tion with other weed killing agents. Thus, the applied to weed foliage from aqueous Solutions Sulfamates may be mixed with ammonium thio containing from about three to twenty per cent. Cyanate, Sodium arsenite, chlorates (ammonium It is hygroscopic at relative humidities above Salts are of course incompatible with chlorates), about seventy per cent and when dried on the and like highly active weed killers, or they may foliage or on clothing of the operator does not be used in conjunction with other sulfamates. have any fire hazard as in the case of Sodium For example, mixtures of ammonium sulfamate chlorate. Quite the contrary, ammonium Sulfa and Sulfamic acid provide the advantages of both mate has a fireproofing action. So that the With the acid and the Sulfamate coupled with the ered foliage coated with ammonium sulfamate 55 higher solubility of the ammonium sulfamate. 2 2,277,744 other methods of application may be em. ivy was particularly sensitive to the ammonium ployed and other ingredients may be added or sulfamate spray treatment. No appreciable new different compositions may be prepared accord growth appeared even though some of the ap ing to the requirements of the different methods plications were made early in the season and in of application. For example, the sulfamates some cases carried out only a few hours before may be applied as a dust. In such case it is an a heavy rain. Examination of the same plots in advantage to include an inert finely divided di the following season have not shown any indi luent such as calcium carbonate, talc, bentonite cation that the poison ivy will grow again. and the like. Such dusts may be prepared as is customary with pest control compositions and 0. applied to the foliage preferably when the foliage Eacample 3 is covered with dew. The dry sulfamates are not The plots involved in this treatment each con actively weed killing agents but become so in tained a post heavily covered with poison ivy the presence of water which may be Supplied which extended to a height of at least six feet. either by a spray solution as described above or 5 For six feet on each side of this post in every by the moisture on the plant foliage, or by Sub direction, making a total area of 144 Square feet, sequent rain or watering. In many cases the all the plants were sprayed. Two gallons of maximum killing effect is obtained only after spray containing one pound per gallon of Weed rain or a period of high humidity irrespective of killer were applied to each plot. Included in whether the application is made from a Solution 20 the plots were such weeds as fall aster, golden or otherwise. In general the methods commonly rod, yarrow, fireweed, one of the wild oat grasses, recommended for the application of translocated wild lettuce, horsenettle, ragweed, Queen Anne's sprays may be followed. lace (wild carrot) and others. All the Succulent The compositions of our invention may include annual or perennial weeds were killed equally basic substances such as the calcium carbonates 25 well by ammonium Sulfamate, ammonium thio mentioned, sodium tetraborate, trisodium phOS cyanate and Sodium chlorate. phate and the like. The compositions also may The most significant difference was observed include fertilizers to aid in preventing steriliza in connection with the Woody perennial Weeds tion of highly treated plots. The sulfamates such as poison ivy. In these tests ammonium may also be used in acid solutions to obtain the 30 sulfamate was strikingly more effective than greater penetrating and wetting effect of the acid ammonium sulfate and ammonium thiocyanate solution and also to obtain the Withering effect and equally as effective as Sodium chlorate. The of the acid on the foliage. Sulfuric acid is the poison ivy was Wilted at the end of One hour, Com cheapest and most commonly used acid and is pletely wilted and bleached within twenty-four suitable. 35 hours, and the plant apparently was dead within In making up composite compositions contain one month. At that time examination of shoots ing more than one weed killing agent base ex more than eighteen inches long revealed that the change may be used to advantage. Thus We are Wood was dead and notwithstanding heavy rains able to mix ammonium sulfamate and Sodium no new growth has appeared. Essentially the thiocyanate, which in the dry state does not have same results were obtained with sodium chlorate, the disadvantages of ammonium thiocyanate but but in the case of ammonium thiocyanate new which in solution has all the advantages thereof growth subsequently appeared at the base of the plus the added advantages of the Sodium and dead shoots and in the case of the ammonium ammonium sulfamates. sulfate there was little apparent damage other The effectiveness of the methods and compo than defoliation. sitions of our invention is shown in the following While We have illustrated our invention with examples: particular reference to fairly concentrated Solu Eacample 1 tions it will be understood that more dilute solu tions may be employed. The strength of the Small plots about eight feet square covered Solution employed will depend upon the purpose with mixed annual weeds were treated with of the application. If the application is made finely divided, solid materials including ammo primarily to kill off succulent annual weeds more nium sulfamate, sulfanic acid, sodium chloride dilute solutions, around two and three per cent, and SC dium chlorate in equivalent concentra Will frequently be sufficient.