other name:sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio)benzoate
CAS No.: [ 123343-16-8 ]
Molecular Formula: C13H10ClN2NaO4S
Pyrithiobac-sodium is primarily a post-emergence herbicide though it can be used from pre- to post-emergence since the compound exhibits residual activity. It is taken up rapidly by roots and shoots and has greatest activity when applied at the 1-3 leaf stage of the weeds. Death occurs 10-14 days after application. Activity is enhanced by the addition of adjuvants such as: non-ionic surfactants; silicon-type adjuvants; and crop oil concentrates. Tank mixes with bromoxynil and/or glyphosate have extended pyrithiobac sodium's weed control spectrum and it is suitable for use on cotton genetically modified to be tolerant to these herbicides. Pyrithiobac has, however, been shown to be antagonistic to some other herbicides in tank mixes. FMC recommends that pyrithiobac-sodium is applied with clomazone pre-emergence, or early post-emergence following clomazone.
When applied post-emergence, pyrithiobac-sodium does not damage the cotton crop at the recommended use rate. Some chlorosis and stunting has been observed, but the quality and yield of cotton is not affected. It is safe to rotational crops. Early-season insecticides can be applied in mixtures or in sequence with pyrithiobac-sodium without crop injury, although some weakening of the cotton fibre has been observed. In field trials, pyrithiobac-sodium gave better control of weeds than commercial standards at lower application rates.
Branched chain amino acid synthesis (ALS or AHAS) inhibitor. Selectivity is based on differing rates of metabolism.
Mode of action
Initial symptoms are cessation of growth and yellowing, followed by necrosis of terminal tissue and death.
Control of a wide range of broad-leaved weeds in cotton. Weeds controlled post-emergence, at 40-105 g/ha include Ipomoea spp., Xanthium spp., and Amaranthus spp.; those controlled pre-emergence, at 35-50 g/ha include Amaranthus spp., Sida spinosa, and Abutilon theophrasti. Phytotoxicity Non-phytotoxic to cotton when applied as directed.
Formulation types SP; SL.
|Acetone insoluble matter||0.5% max.|
GHS complaint Safety Data Sheet (SDS) for commercial product of Pyrithiobac Sodium is available uopn requested.