Effects of Adjuvants and Environment During Plant Development on Glyphosate Absorption and Translocation in Field Bindweed (Convolvulus arvensis)

Abstract

Absorption and translocation of glyphosate [N-(phosphonomethyl)glycine] with and without adjuvants were examined in field bindweed (Convolvulus arvensisL. # CONAR) to develop an understanding of the influence of selected adjuvants and environment before application on glyphosate activity. Light intensity and humidity during plant development resulted in differences in14C-glyphosate absorption. When applied in water or with an oxysorbic (20 POE) (polyoxyethylene sorbitan monolaurate) adjuvant, an average of 9% of the glyphosate was absorbed in plants grown in high light intensity, low humidity (HLLH) before treatment, compared to an average of 21% in plants grown in low light, high humidity (LLHH) before treatment, respectively. Amounts of epicuticular wax on HLLH field bindweed were almost three times as great as on LLHH leaves and may explain absorption differences. No differences in glyphosate absorption were observed between glyphosate applied with oxysorbic or no adjuvant even though the oxysorbic adjuvant effectively reduces surface tension. Absorption was increased two- to threefold with a polyethoxylated tallow amine adjuvant (MON 0818) compared to no adjuvant. Unlike absorption without adjuvant or with oxysorbic adjuvant, there were few absorption differences in plants grown in different environments before application. Absorption continued for 24 to 36 h after application regardless of adjuvant. Reductions in MON 0818 concentration and subsequent necrosis resulted in increased movement of radioactivity away from the site of application.

Morphological disparities in the epidermal and anatomical features of the leaf among wild Brassica juncea populations

“…The leaves of higher plants are covered by a cuticle, that is, an extracellular membrane that usually is considered as the main barrier against foliar absorption (Bukovac 1976). Sherrick et al. (1986) investigated the effects of adjuvants and the environment during plant development on the level of glyphosate absorption and translocation in field bindweed ( C. arvensis L.) and confirmed that the thickness of the cuticle of bindweed leaves affects the herbicide's level of efficacy.…”

Absorption, localisation, translocation and activity of glyphosate in barnyardgrass (Echinochloa crus-galli (L) Beauv): influence of herbicide and surfactant concentration

“…Translocation mirrored absorption (Fig 6b). Similarly, in field bindweed ( Convolvulus arvensis L) glyphosate absorption was increased two‐to three‐fold with MON 0818 compared to no adjuvant; reductions in the concentration of MON 0818 lowered necrosis and resulted in increased movement of radioactivity away from the site of application 12…”

“…The effect of adjuvants on absorption and translocation of glyphosate has been examined by several workers 8–11. Sherrick et al 12 reported that absorption of [ 14 C]glyphosate was increased two‐ to three‐fold by incorporation of a polyethoxylated tallow amine surfactant (MON 0818). Reduction in surfactant concentrations below 10 g litre −1 caused less initial necrosis and resulted in increased translocation of [ 14 C]glyphosate from the site of application.…”

Effects of two surfactant series on the absorption and translocation of 14C‐glyphosate in sicklepod and prickly sida

“…However, with the addition of either surfactant series, a significantly higher absorption of the 14 C‐glyphosate was recorded by both weed species. Sherrick et al. (1986) reported a two‐to‐three‐fold increase in the absorption of glyphosate with a polyethoxylated TA adjuvant.…”