Alkyl polyglycoside, a new glyphosate Surfactant to boost herbicide performance
Updated: Jul 13, 2020
In recent years, research has found that the traditional glyphosate adjuvant fatty amine polyoxyethylene has an irritating effect on skin and eyes, highly poison to fish, glyphosate-resistant crops often have a decline in output. Alkylphenol polyoxyethylene based adjuvants are degrading slowly, the final degradation alkyl phenol is toxic, so these adjuvant are potentially harmful. Therefore, looking for safe and efficient adjuvant is a new direction for research and development.
Alkyl polyglycoside (APG) is derived from glucose and natural fatty alcohols, with a series of excellent properties: no waste during production, fast degradation, lower irritation to skin and eyes. Therefore alkyl polyglucoside based adjuvants getting more trend in the Glyphosate surfactant market.
1.Synergistic effect of APG on glyphosate
By indoor and outdoor field weed control experiments, the result shows Alkyl polyglycosides with glyphosate, even in low-temperature environments with an average temperature of 17 ℃, whether it is annual or perennial weeds, its speed, controls of visual and fresh weight are equivalent or slightly higher than the traditional preparations.
To further study the synergistic effect and mechanism of APG on glyphosate, We doing an absorption test on the leaf surface.
The chart shows that as the absorption time increases, the absorption rate increases. Samples show a significant difference in the absorption rate. The order of the absorption rate is APG> Traditional adjuvant> Glyphosate. The absorption test was consistent with the results of the indoor and outdoor field weed control tests. Further proves that APG has an excellent synergistic effect on glyphosate.
2. Effect of surface tension
Dilute different samples to 0.10% and 0.20% respectively at room temperature (25.8 ℃)
The surface tension results are shown in the chart.
As in this chart: APG has significantly reduced the surface tension of glyphosate
Dilute samples to 0.1% at room temperature to measure the wetting contact angle θ of a droplet on the leaf surface.
All sample‘s contact angles are below 90º, indicating that they are all partially wet.
The wettability of glyphosate with adjuvant is noticeable better than glyphosate without adjuvant. The wettability is APG >Traditional adjuvant> Glyphosate. It is indicating that based on its superior wetting properties, APG has excellent synergistic effects on glyphosate,
Glyphosate must be attached to the leaf surface to absorbed into the leaf epidermal cells. Experiments show that the better the wettability and absorption rate has a better control effect.
Theoretically, better wetting and spread can effectively increase the contact area, APG can help glyphosate transport and its effect on targets, at the same time, keep the glyphosate moisturizing to maintain the hydrated and dissolved state, which is conducive for absorption.
In other words, APG’s excellent synergistic effect on glyphosate is directly related to its good wetting properties.
Plant epidermis wax layer is composed of organic substances, such as fatty acids, esters, alcohols, glycols.APG can dissolve, destroying the wax layer, and promoting the penetration of glyphosate. At the same time, APG prevent or gradually reduce the formation of crystals, the physical state of glyphosate will be a thin amorphous layer, it's in close contact with the surface of stratum corneum, further improve absorption of the herbicide.
APG also can help glyphosate to directly absorbed through foliar stomata. This fast stomatal absorption can reduce the volatilization of herbicide after foliar treatment, and can prevent the herbicide from being washed by rain to reduce environmental pollution.