Location: Southern Weed Science Research

Title: Ragweed Parthenium (Parthenium hysterophorus) Control with
Preemergence and Postemergence Herbicides

Authors
item Reddy, Krishna
item Bryson, Charles
item Burke, Ian - WASHINGTON STATE UNIV

Submitted to: Weed Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 30, 2007
Publication Date: January 3, 2008
Citation: Reddy, K.N., Bryson, C.T., Burke, I.C. 2008. Ragweed
Parthenium (Parthenium hysterophorus) Control with Preemergence and
Postemergence Herbicides. Weed Technology 21:982-986.

Interpretive Summary: Ragweed parthenium is an invasive non-native
weed with increased frequency of detection in the southern US.
Research on control of ragweed parthenium with herbicides in the US is
mostly lacking. Scientists at Southern Weed Science Research Unit,
Stoneville, MS have conducted studies to control of ragweed parthenium
with several preemergence (PRE) and postemergence (POST) herbicides
registered for use in corn, cotton, peanut, rice, and soybean.
Norflurazon, clomazone, fluometuron, metribuzin, diuron, and
flumioxazin provided excellent PRE control of ragweed parthenium.
Glyphosate, glufosinate, chlorimuron, and trifloxysulfuron applied at
rosette-stage provided excellent control of ragweed parthenium. At
bolted-stage, glyphosate, glufosinate, and trifloxysulfuron controlled
greater than 86% of ragweed parthenium. Overall, efficacy of POST
herbicides was better on rosette plants than on bolted plants. These
findings indicate that norflurazon, clomazone, fluometuron,
flumioxazin, halosulfuron, and trifloxysulfuron could provide
effective control of ragweed parthenium in the crops for which they
are labeled.

Technical Abstract: Field and greenhouse experiments were conducted
during 2005 and 2006 at Stoneville, MS to determine control of ragweed
parthenium with several preemergence (PRE) and postemergence (POST)
herbicides registered for use in corn, cotton, peanut, rice, and
soybean. Norflurazon, pendimethalin, clomazone, diuron, fluometuron,
pyrithiobac, dimethenamid, flumetsulam, imazaquin, S-metolachlor,
metribuzin, chlorimuron, atrazine, simazine, flumioxazin, and
quinclorac were applied PRE. Ragweed parthenium control was highest
with norflurazon (100%) and clomazone (100%) followed by fluometuron
(96%), metribuzin (90%), diuron (87%), flumioxazin (84%), chlorimuron
(77%), and quinclorac (67%) at 6 wk after treatment (WAT) under
greenhouse conditions. Control of ragweed parthenium was less than 58%
with all other herbicides. Ragweed parthenium appears to be highly
sensitive to pigment and photosynthetic inhibitors compared to
herbicides with other modes of action. Glyphosate, glufosinate,
paraquat, bentazon, acifluorfen, chlorimuron, halosulfuron, MSMA,
bromoxynil, atrazine, 2,4-D, flumioxazin, trifloxysulfuron, and
clomazone were applied POST to field-grown rosette and bolted plants.
Glyphosate, glufosinate, chlorimuron, and trifloxysulfuron applied at
rosette-stage provided greater than 93% control of ragweed parthenium
at 3 WAT. Halosulfuron, MSMA, bromoxynil, 2,4-D, and flumioxazin
controlled 58 to 90% rosette ragweed parthenium at 3 WAT. Ragweed
parthenium control with all other POST herbicides was less than 38%.
At bolted-stage, glyphosate, glufosinate, and trifloxysulfuron
controlled 86 to 95% ragweed parthenium and control was 61 to 70% with
chlorimuron, halosulfuron, and 2,4-D. Overall, efficacy of POST
herbicides was better on rosette plants than on bolted plants. Amino
acid synthesis and glutamine synthase inhibitors were more active than
herbicides with other modes of action. These results indicate that
norflurazon, clomazone, fluometuron, flumioxazin, halosulfuron, and
trifloxysulfuron could provide effective control of ragweed parthenium.

http://genes.pp.ksu.edu/research/publications/Publications.htm?seq_no_115=210331