Foliar Uptake and Transport of 2,4-D and Picloram by Drummond's Goldenweed (Isocoma drummondii)

Abstract

Detached leaves of Drummond's goldenweed [Isocoma drummondii(T. & G.) Greene] absorbed the potassium salt of 2,4-D [(2,4-dichlorophenoxy)acetic acid] from aqueous solutions more slowly than did sunflower (Helianthus annuusL.), and both species absorbed less of the potassium salt of picloram (4-amino-3,5,6-trichloropicolinic acid) than 2,4-D. However, there was no difference in absorption of the herbicides by Drummond's goldenweed leaves after 6 h of exposure to solutions containing 0.5% (v/v) surfactant. Attached Drummond's goldenweed leaves absorbed about 50% of available 2,4-D (diethylamine) and 25% of available picloram (potassium salt) within 5 days after spraying in the field during July or November. Herbicide accumulation in Drummond's goldenweed taproots after spray applications was generally slow, regardless of season, but translocation to taproots was substantially greater after application in November than after treatment in March or July. Accumulation of picloram in taproots was faster and more extensive than accumulation of 2,4-D. However, based on mortality at 6 months after treatment, both herbicides were translocated in quantities adequate for control. The greater effectiveness of picloram, despite its low foliar uptake, than 2,4-D is attributed to its greater mobility and root uptake in Drummond's goldenweed after broadcast sprays.

Inheritance and Physiological Basis for 2,4-D Resistance in Prickly Lettuce (Lactuca serriola L.)

“…& A. Gray) Greene] 28 and perennial Glycine species 29 were similar to the absorption pattern observed in both biotypes of prickly lettuce. Studies of auxin resistance in hemp-nettle revealed 50% less acropetal movement of 14 C in MCPA-resistant compared to MCPAsusceptible biotype.…”

“…Environmental and species effects on absorption and translocation of 2,4-D are well documented. − Values for absorption of 2,4-D have varied from 18 to 70% depending upon plant species, study duration, and environmental conditions. − For more recent example comparisons, the biphasic absorption of 2,4-D in Drummond’s goldenweed [Isocoma drummondii (Torr. & A.…”

Absorption and Translocation of 2,4-D in Plants of Memora peregrina

“…Absorption 48 h after applied, the herbicide radioactive was 24.26 and 23.81% when used the product alone. Percentage of 2,4-D absorbed by Isocoma drummondii was 12% in 48 h after application in the plant, [11] this value was minor than found in this work. Absorption of propanil in rice was 10.72% of the herbicide applied in 20 min after spraying.…”

“…[4] Several researches have been done involving absorption and translocation of 2,4-D in different species as Silene vulgaris (Moench) Garcke, [5] Sisymbrium orientale Torn., [6] Apocynum cannabinum L., [7,8] and Asclepias syriaca L. [8] However, many authors also evaluated absorption and translocation of 2,4-D in association with picloram. Because of this association the control for Euphorbia esula L. [4,9,10] and Isocoma drummondii (T. & G.) has been achieved by Greene [11] with great success as method of control.…”

Molecular and physiological characterization of six‐way resistance in an Amaranthus tuberculatus var. rudis biotype from Missouri

“…The plants of both MO‐Ren and MO‐S biotypes exhibited rapid absorption of [ 14 C] 2,4‐ D and about 70% of the applied herbicide was absorbed within 24 h of treatment. Various environmental, species and application factors can affect 2,4‐ D absorption and previous research has shown that 2,4‐ D absorption can range from 10% to 99% in different species …”