Granule, water dispersible evaluation

Hovde, D. A. "Laboratory Development and Evaluation of Water Dispersible Granules" Pesticide Formulation and Application Systems, 3rd Conference STP 828, American Society of Testing and Materials Philadelphia PA. December, 1983. 

This spring Elanco Products Company (a Division of Eli Lilly and Company) introduced a 60 /o dry flowable (or water dispersible granule) formulation of BALAN. BALAN is a preemergence, dinitroaniline herbicide used on peanuts and lettuce. BALAN Dry Flowable is an addition to formulations of BALAN which are produced and sold by Elanco. BALAN LC, a 1.5 Ib/gal emulsifiable concentrate which has been on the market for several years, is often tank mixed with several other agrichemicals. Therefore, it was critical to evaluate this new product form for tank mix performance with all agrichemicals with which it could be tank mixed. 

If the pesticide constituent is a solid that is not soluble in oil or water, dien either a suspension concentrate (SC) or a water dispersible granule (WG, WDG) can be evaluated. A suspension concentrate is a dispersion of active ingredient in a continuous aqueous phase. The concentrated suspension is then diluted in the spray tank prior to application. If the solid has to be dispersed in an oil phase, then the oil flowable (OD) has to spontaneously enuilsify if it is to be diluted into an aqueous spray tank. 

When a cold starch sol is treated with adsorbents (usually cotton), the A-fraction is preferentially removed. Subsequently, it may be stripped from the adsorbent with hot water. This method of fractionation involves no chemical degradation and yields a relatively pure B-fraction. However, the A-fraction is apt to be badly contaminated, both with B-fraction and with incompletely dispersed granules. Only small amounts of starch can be processed and quantitative evaluation of the fractions does not appear to be feasible. 

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