TITLE:
Evaluation of Preemergence Herbicides for Crop Safety and Weed Control in Safflower
AUTHORS:
Prashant Jha, Vipan Kumar, Charlemagne A. Lim, Ramawatar Yadav
KEYWORDS:
Safflower, Weed Control, Preemergence Herbicide, Kochia, Russian-Thistle
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.8 No.10,
September
5,
2017
ABSTRACT: Weed
management in safflower (Carthamus tinctorious L.) is a major challenge for growers due to very limited
herbicide options
available, particularly
for broadleaf weed control. Field experiments were conducted at the Montana
State University Southern Agricultural Research Center (MSU-SARC) near Huntley,
MT in 2015 and 2016 to evaluate preemergence (PRE) soil-residual herbicides for crop safety and season-long broadleaf weed
control in safflower. Among
all herbicide programs tested, only sulfentrazone (105 g·ai·ha-1) alone
or with pendimethalin (1064 g·ai·ha-1) caused 4% to 12%
early-season visible injury to safflower, although
the injury was not evident beyond 30 DAT. Sulfentrazone alone or with pendimethalin and pyroxasulfone (59 g·ai·ha-1) with pendimethalin had a season-long residual
activity on kochia [Kochia scoparia (L.) Schrad] and Russian-thistle (Salsola tragus L), with 89% to 99% control at 60 DAT, and up to 98% reduction in weed
density compared
with dimethenamid-P (213 g·ai·ha-1) and S-metolachlor
(433 g·ai·ha-1) at 65
DAT. Pyroxasulfone (59 or 118 g·ai·ha-1) alone
or dimethenamid-P with pendimethalin provided
a moderate to good control (65% to 79% at 60 DAT) of kochia and
Russian-thistle. However, the end-season control of kochia or Russian-thistle
was inadequate ( S-metolachlor
alone program. Safflower
grain yield with sulfentrazone alone or with pendimethalin, pyroxasulfone alone
or with pendimethalin, and dimethenamid-P with pendimethalin averaged 3559 kg·ha-1, which
was 195% higher compared with the nontreated check. In conclusion, sulfentrazone and pyroxasulfone or dimethenamid-P in combination
with pendimethalin will be effective PRE
herbicide programs for kochia and Russian-thistle control in safflower.