Studies on a new group of biodegradable surfactants for glyphosate

Abstract

The effectiveness of a homologous series of biodegradable rapeseed oil derivatives (triglyceride ethoxylates; Agnique RSO series containing an average of 5, 10, 30 and 60 units of ethylene oxide (EO) as adjuvants for foliage-applied, water-soluble, systemic active ingredients was evaluated employing glyphosate as an example. Previous experiments had revealed that the surfactants used are not phytotoxic at concentrations ranging from 1 to 10 g litre-1. The experiments were performed using Phaseolus vulgaris L and nine selected weed species, grown in a growth chamber at 25/20 (+/- 2) degrees C day/night temperature and 40/70 (+/- 10)% relative humidity. The surfactants were evaluated for enhancement of spray retention, and foliar penetration biological efficacy of glyphosate. Glyphosate was applied at a concentration of 43 mM. The surfactants were added at concentrations of 1 g litre-1. The commercial glyphosate 360 g AE litre-1 SL Roundup Ultra and unformulated glyphosate served as references. The surfactants used improved spray retention, foliar penetration and biological efficacy. Some of the formulations were comparable to the performance of Roundup Ultra in the aspects evaluated; some were even more effective in enhancing spray liquid retention and promoting glyphosate phytotoxicity in several plant species. In these studies Agnique RSO 60 generally was most effective.

Food safety in Thailand 1: it is safe to eat watermelon and durian in Thailand

“…The higher concentration of pesticide in some parts of plants could be caused by other factors [39] such as active transport system, pesticide deposition on the plant surface, and adsorption processes [40]. Foliar uptake of pesticides is a complex process, depending on the characteristics of plant leaf surface, physicochemical properties and concentration of the active pesticide ingredients and additives, and environmental conditions [41]. It is possible that the pesticides may enter the watermelon fruit via the vine.…”

Fractioning of an ethoxylated soybean oil adjuvant and studies on the potency of the fractions in combination with bromoxynil octanoate and sulfonylurea herbicides

“…Modified vegetable oils are not phytotoxic, environmental friendly and enhance herbicide efficacy (Abribat 2001, Ruiter de et al 1998). Due to these facts, they are interesting for pesticide formulations (Haefs et al 2002). Seed oil derivates are generally big molecules which are composed of a variety of long chained fatty acids.…”

Glyphosate-based phospho-organic herbicides – an outline of action, metabolism and the selected effects on humans and other organisms

“…Arch Physiother Glob Res 2015 19 (2): [35][36][37][38][39][40][41][42][43][44][45] From the ecological perspective, the use of glyphosate should be regarded as another factor for plant selection. Thus, the appearance of the varieties of several wild plant species of various GP resistances was not surprising [19][20][21].…”

“…The remaining herbicide components present in traded preparations can enhance or widen their effects (e.g. on hormonal metabolism); therefore, less harmful substitutes have been searched for [38]. Escherichia coli MG1655 (GP, POEA) EC50 (inhibition of colony growth after 5-hour incubation) for isopropylamine salt in the concentration of 506 mg/L medium, 548mg/L and 706mg/L for preparations with and without POEA , respectively [40] Pseudomonas putida KT2440 (GP, POEA) EC50 (inhibition of colony growth after 5 hours) at the concentration of 343 mg/L medium for isopropylamine salt; 340 mg/L and 515 mg/L for preparations with surfactant or otherwise, respectively [40] rat (GP) 35-40% of 10 mg/kg b.w.…”

“…intravenously and 400 mg/kg b.w. orally -half-life from circulation 10 and 15 h, respectively; between post-administration hour 2 and 3, peak AMPA levels were observed, constituting about 10 % of maximum GP concentration [42] rat (GP) animals receiving 0.5% and 1% solution of GP in water during pregnancy showed lower weight increases (which did not concern foetal body weight); visible differences in the activity of cytoplasmic enzymes of NADPH metabolism (glucose-6-phosphate dehydrogenase, malate and isocitrate dehydrogenase) of the maternal and foetal liver, myocardium, and brain [43] Arch Physiother Glob Res 2015 19 (2): [35][36][37][38][39][40][41][42][43][44][45] Daphnia magna (GP, GP+POEA) acute toxicity (EC50 48h) was found in lower ranges of GP concentrations compared to both substances present together; reduced rate of organisms growth was observed at similar exposures to given doses with the tendency for quicker action of higher GP+POEA concentrations. At GP+POEA doses exceeding 1 mg/L, the majority of animals reached the reproductive age yet produced infertile gametes or gametes unable to develop embryos [44] Tadpoles of 4 species of North American tailless amphibians (GP, POEA, GP+PO-EA)…”