Ag. Hager et al., Soil moisture, relative humidity, and bentazon affect imazethapyr absorption and translocation in common ragweed (Ambrosia artemisiifolia), WEED TECH, 13(2), 1999, pp. 320-323
Soil moisture, relative humidity (RH), and the addition of bentazon were ex
amined for effects on absorption and translocation of C-14-imazethapyr in c
ommon ragweed, When common ragweed was growing under conditions of low soil
moisture (-300 kPa), absorption of C-14-imazethapyr was reduced from 51 to
42%. Translocation of 14C-imazethapyr was not affected by soil moisture. I
n the absence of bentazon, absorption and translocation of C-14-imazethapyr
was similar at 65 and 85% RH 48 and 168 h after treatment. Bentazon decrea
sed absorption of C-14-imazethapyr from 61 to 26% at 65% RH and from 65 to
57% at 85% RH 168 h after treatment. Bentazon decreased translocation of C-
14-imazethapyr from 35 to 9% at 65% RH and from 30 to 21% at 85% RH when av
eraged over time. This reduction in the absorption and translocation of C-1
4-imazethapyr when bentazon was added may result in a reduction in common r
agweed control compared to imazethapyr alone when RH is 65% or lower.