Abstract:
Wild barley has invaded wheat fields ever since fla
mprop-isopropyl was outdated in
Iran. Newly developed herbicides such as sulfosulfu
ron or sulfosulfuron plus metsulfuron-
methyl can control it at higher than recommended do
sages, but causing significant wheat
injury. Hence, two dose-response experiments were c
onducted to evaluate their efficacy
when tank-mixed with thirteen different vegetable o
ils, at the Ferdowsi University of
Mashhad, Iran, during 2013. Moreover, a wheat culti
var (Gaskogen) was also treated
with effective dose of 90% (ED
90
) of both herbicides (21.44 grams active ingredient
(g ai)
of sulfosulfuron ha
-1
and 41.95 g ai of sulfosulfuron plus metsulfuron-m
ethyl ha
-1
) with
and without each vegetable oil to check selectivity
. Averaged over vegetable oils, the
effective dose of 50% (ED
50
) was decreased 2.6- and 3.0-fold with sulfosulfuro
n and
sulfosulfuron plus metsulfuron-methyl, respectively
. Among the evaluated vegetable oils,
cottonseed and coconut oil were the best ones to en
hance the efficacy of both herbicides.
The castor oil had the least effect. A negative cor
relation was observed between the
efficiency of vegetable oils and its unsaturated/sa
turated fatty acids ratio. No phytotoxic
effect on wheat was observed when these herbicides
were applied with or without the
vegetable oils.
Keywords
: Crop selectivity, Herbicide efficacy, Penetrant a
gent, Vegetable oils, Wild barley.
