Annual ryegrass and volunteer cereal control in lupins using selective post-emergent herbicides

Abstract

The relative effectiveness of herbicides from the aryloxyphenoxypropionate (fop) and cyclohexanedione (dim) chemical families for the control of volunteer wheat (Triticum aestivum L.), oats (Avena sativa), triticale (Triticum x Secale) and annual ryegrass (Lolium rigidum Gaud.) in narrow-leafed lupins (Lupinus angustifolius) were evaluated over a 3-year period near Rutherglen in north-eastern Victoria. Herbicides tested included diclofop-methyl, fluazifop-pethyl, haloxyfop, propaquizafop, quizalofop-p-ethyl, clethodim, cycloxydim, sethoxydim, and mixes of fluazifop-p-ethyl + diclofop-methyl, and fluazifop-pethyl + sethoxydim. Effective grass control needed to prevent disease carryover is defined as greater than 98%. Haloxyfop at 78 g a.i./ha and clethodim at 120 g a.i./ha consistently gave greater than 98% control of all target species. Quizalofop-p-ethyl at 12 g a.i./ha gave greater than 98% control of volunteer cereals but annual ryegrass control ranged from 83.7 to 44.1%. Cycloxydim at 100 g a.i./ha produced similar oat and ryegrass control to that of 563 g a.i./ha diclofop-methyl. Sethoxydim at 93 g a.i./ha, gave significantly (P < 0.05) better control of annual ryegrass than the recommended rates of diclofop-methyl, fluazifop-p-ethyl and propaquizafop. The addition of 47 g a.i./ha sethoxydim to 32 g a.i./ha fluazifop-p-ethyl significantly improved ryegrass control than low rates of fluazifop-p-ethyl alone.