TITLE:
Tolerance of mung bean to postemergence herbicides
AUTHORS:
Nader Soltani, Christy Shropshire, Peter H. Sikkema
KEYWORDS:
Height; Injury; Seed Moisture Content; Shoot Dry Weight; Yield
JOURNAL NAME:
Agricultural Sciences,
Vol.4 No.10,
October
10,
2013
ABSTRACT:
There are a limited number of postemergence (POST) herbicides available
for weed management in mung bean production in Ontario. Five field studies were
conducted in 2010, 2011 and 2012 near Exeter, Ontario and in 2011 and 2012 near
Ridgetown, Ontario to determine the tolerance of mung bean to fomesafen, bentazon,
bentazon + fomesafen and halosulfuron applied POST at the 1X and 2X proposed
manufacturer’s recommended rate. Bentazon caused 5%-29%, 4%-31%, and 2%-18%
injury, fomesafen caused 3%-17%, 1%-7%, and 0%-6% injury, bentazon +
fomesafen caused 6%-40%, 4%-37%, and 1%-20% injury, and halosulfuron
caused 13%-65%, 8%-75%, and 5%-47% injury in mung bean at 1, 2, and 4
weeks after treatment (WAT), respectively. At Exeter, fomesafen had no adverse
effect on height of mung bean but bentazon, bentazon + fomesafen and
halosulfuron decreased mung bean height as much as 5% compared to the untreated
control. At Ridgetown, there was no
decrease in mung bean height due to the herbicides applied. Fomesafen
had no adverse effect on shoot dry weight of
mung bean but bentazon, bentazon + fomesafen and halosulfuron
decreased shoot dry weight of mung beans as much as 43%, 47%, and 57%, respectively.
Fomesafen, bentazon, bentazon + fomesafen and halosulfuron had no adverse
effect on the seed moisture content and
seed yield of mung bean with the exception of halosulfuron applied POST
at 70 g ai ha-1 which increased seed moisture content 0.4% at
Exeter and 1.4% at Ridgetown and decreased yield 16% at Exeter compared to
the untreated control. Based on these results, there is not an adequate
margin of crop safety for bentazon, bentazon + fomesafen andhalosulfuron applied POST in mung bean. However,
there is potential for fomesafen applied POST at the proposed manufacturer’s
rate of 240 g ai ha-1 in
mung bean production.