Effect of Droplet Size and Herbicide Concentration on Absorption and Translocation of¹⁴C-2,4-D in Oriental Mustard (Sisymbrium orientate)

Abstract

Individual droplets of14C-2,4-D dimethylamine (DMA) were applied to oriental mustard seedlings to determine the effect of droplet size and herbicide concentration on absorption and translocation 1 or 3 d after application. Absorption of14C-2,4-D was generally not affected by droplet size which ranged from 198 to 2760 μm. However, the percentage of absorbed14C-2,4-D that was translocated away from the treated leaf increased as droplet size decreased. Absorption of14C-2,4-D either increased slightly or was not affected by increased herbicide concentration, but translocation of absorbed14C-2,4-D was reduced as herbicide concentration increased. Absorption and translocation of14C-2,4-D DMA were reduced when applied after a drop of 21.3 mM commercially formulated 2,4-D had been applied at the same location on the leaf. These results indicate that large amounts of 2,4-D, either in the form of large droplets or a more concentrated herbicide solution, inhibit translocation of 2,4-D from oriental mustard leaves.

Influence of two fatty amine surfactants on foliar absorption, translocation, and efficacy of 2,4-D triethanolamine salt

“…This observation supports the suggestion made in a previous study (Wolf et al, 1992) on the absorption and translocation of 2,4-D dimethylamine salt in oriental mustard (Sisymbrium orientale). The authors suggested that localized damage to the conducting tissue of the plant caused by an increased concentration of the herbicide and/or the formulation ingredients may reduce the herbicide translocation from the treated leaf.…”

2,4-D Past, Present, and Future: A Review

“…However, 2,4-D acid uptake was shown to be greatest with smaller droplets (0.5 lL compared with 10 lL) and with a larger total volume (100 lL compared with 10 lL) applied to the leaf of common bean (Knoche and Bukovac 1999). The concentration of 2,4-D in droplets did not affect uptake, but translocation was reduced by 10 to 14% when the concentration increased eightfold (Wolf et al 1992). The true impact of droplet size and carrier volume on 2,4-D uptake and translocation may be difficult to determine because of differences between study methods used (i.e., nozzle types, spray pressure, application equipment, etc.)…”

“…An optimum droplet size, carrier volume, or ae concentration to maximize 2,4-D uptake in fava bean was not determined, and increasing the amount of 2,4-D applied reduced the efficiency of uptake (Stevens and Bukovac 1987). Similarly, 2,4-D dimethylamine uptake was not influenced by droplet size, but translocation decreased as droplet size increased in oriental mustard (Sisymbrium orientale) (Wolf et al 1992). However, 2,4-D acid uptake was shown to be greatest with smaller droplets (0.5 lL compared with 10 lL) and with a larger total volume (100 lL compared with 10 lL) applied to the leaf of common bean (Knoche and Bukovac 1999).…”

Spray droplet size and carrier volume effect on dicamba and glufosinate efficacy

“…Previous research demonstrated increased control across multiple herbicides and weed species as droplet size decreased to 100 µm . Glyphosate, a systemic herbicide, had greater absorption and translocation with Coarse droplets; however, this guideline was not consistent across systemic herbicides because translocation of 2,4‐D (systemic herbicide) increased as droplet size decreased, indicating that droplet size plays a role in 2,4‐D efficacy . Additionally, no losses in herbicide efficacy as droplet size increased were observed for several contact herbicides .…”