Patent Application
20090325805
1) Nalewaja; John D Aug. 19, 1997 U.S. Pat. No. 5,658,855
2) M. Green et al., “Surfactant Structure and Concentration Strongly Affect Rimsulfuron Activity”, Weed Technology, 1993, vol. 7:633-640.
3) Woznica, Zenon J.; et al. Jul. 3, 2003 Patent Application Number 20030125211.
4) Woznica, Zenon J.; et al. Jun. 5, 2003 Patent Application Number 20030104947
It is known that increasing the pH of the spray solution for sulfonylurea herbicides increases the performance of these herbicides1. This can be achieved by using a number of pH adjustors which can also be applied with fertilizers or adjuvant blends. It is thought that the effect is due to an increase in solubility of these types of herbicides as the pH increases (WSSA Herbicide Handbook—7th Edition, 1994). This invention pertains to the use of a pH adjustor in a blend of cat-ionic surfactants. It was discovered that Sulfosulfuron, a sulfonylurea herbicides, performed better when the pH adjustor was combined with a cat-ionic surfactant (amine) rather than an oil or a blend of non-Ionic surfactants as taught by Nalewaja et. al.
The present invention relates to adjuvant compositions for use in the spray carrier of post emergence herbicides applied as an aqueous spray solution to crops infested with undesired weeds to control the infesting weeds. Broadly, the adjuvant compositions of the invention comprise an amine or ammonia compounds for adjusting the pH to the alkaline range of 9-10.5 and a cat-ionic surface active agent with a high Hydrophilic-Lipophilic balance (HLB), which functions as a spreader or sticker and penetrant for use with postemergence sulfonylurea and sulfonamide herbicides when applied in a aqueous spray composition.
Normally the adjuvant is applied as 0.5% v/v (volume to volume) of the aqueous spray solution. In other words the present invention is diluted with water (99.5%) to which is added the desired herbicide, normally sulfosulfuron. However, increases in activity have been seen with other sulfonylurea or sulfonamide herbicides.
This invention pertains to the unexpected increase in activity seen when sulfosulfuron was applied with a cat-ionic surfactant plus a pH adjustor that increased the pH to a pH of 9-10.5 (Table 1). As opposed to the increase in activity that was predicted to happen when applied with an oil based or non-ionic surfactant with a pH adjustor as taught by Nalewaja et. al.
This effect has been seen with both wild oat (Avena fatua) Table 1 and downy brome (Bromus tectorum) Table 2. The increase in activity has been seen with different formulation of tallow amine cat-ionic surfactant and a pH increasing additive (Table 3).
The constituents of the proposed mixture are normally made up of cat-ionic amine surfactant and a pH adjustor that increases the pH. The cat-ionic surfactant Alkyl Dimethylamines, Alkyl Amidopropylamines, Alkyl Imidazoline, Derivatives Quaternised, Amine Ethoxylates, Quaternary Ammonium Compounds
