Applications of Metribuzin for The Control of Rigid Brome (Bromus rigidus) in No-Till Barley Crops of Southern Australia

Abstract

Field experiments were conducted at Warooka and Rudall on the Yorke and Eyre Peninsula of South Australia during 2004 and 2005 to investigate the effectiveness of metribuzin for the selective control of rigid brome in no-till sown barley. Metribuzin (135 to 203 g ai/ha) incorporated by sowing (IBS) was more effective in controlling rigid brome (> 67%) than the same herbicide dose applied POST. Although IBS metribuzin at the highest rate (270 g/ha) provided effective weed control (82 to 90%), it was more phytotoxic to barley, reducing crop density by 23% relative to the nontreated control at Rudall. Soil at Rudall had low clay and organic matter content. In contrast, tank mixtures of metribuzin (203 g/ha) with pendimethalin, applied IBS, provided reliable rigid brome control (89 to 93%) and resulted in little crop damage (< 5%). Over the site-by-year combinations studied, all herbicide-treated barley at Warooka and Rudall yielded 6 to 50% more grain than the nontreated crop. Although metribuzin provides growers with an opportunity to selectively control rigid brome in no-till barley, high rates (≥ 203 g/ha) of this herbicide on sandy textured soils can result in significant crop damage.

Growth stage of Phalaris minor Retz. and wheat determines weed control and crop tolerance of four post-emergence herbicides

“…Therefore, the best weed control with this herbicide was observed when it was applied at Z21-23 wheat stages. Kieloch et al (2006) indicated that pinoxaden can provide high levels of weed control even at late weed growth stage which was also supported by this study.…”

Non‐target‐site‐based resistance to ALS‐inhibiting herbicides in six Bromus rigidus populations from Western Australian cropping fields

“…Metribuzin can also be used selectively to control Bromus spp. in barley crops, although high rates may cause crop damage on some soil types 36. Most importantly, weed numbers should be kept at a minimum through the use of integrated weed management options such as competitive crops and tools that deplete the soil weed seed bank, as resistance to some of the alternative herbicide control options has already been reported 16–18…”

Identification and validation of QTL and their associated genes for pre-emergent metribuzin tolerance in hexaploid wheat (Triticum aestivum L.)

“…Infestation of broad-spectrum weeds in dry-land farming is a major yield-reducing factor (up to 50%) in wheat [ 1 ]. Metribuzin [4-amino-6-(1,1-dimethylethy1)-3-(methylthio)-1,2,4-triazin-5-(4H)-one], a triazine herbicide (group C), is a versatile herbicide that controls a wide range of weeds in dry-land farming systems [ 1 , 2 ] and is registered for use in some wheat cultivars. However, most wheat cultivars lack selectivity to metribuzin due to narrow safety margins that result in crop damage.…”