Tolerances of canola, field pea, lupin and faba bean cultivars to herbicides

Abstract

The grain yield responses of cultivars of canola, field pea, lupin and faba bean to the recommended rates and twice the recommended rates of pre- and post-emergence herbicides were examined in field trials conducted at Wagga Wagga, New South Wales, from 1986 to 1989. Significant (P<0.05) reductions in grain yield of some field pea cultivars resulted from the recommended rate of registered post-emergence herbicides: Cressy Blue (22%), Derrimut (20%) and Dundale (13%) with metribuzin (0.23 kg a.i./ha); Wirrega (26%) with cyanazine (1.0 kg a.i./ha); Wirrega (15%) and Maitland (13%) with methabenzthiazuron (0.6 kg a.i./ha). The canola lines Hyola 30 and BLC 198-82 also had significant reductions in yield (16-19%) from the recommended rate of clopyralid (0.09 kg a.i./ha). There were differences in cultivar (or advanced line) tolerance to other herbicides at twice the recommended rate: clopyralid (0.18 kg a.i./ha) applied post-emergence in canola; diflufenican (0.2 kg a.i./ha) and MCPA (0.75 kg a.i./ha) applied post-emergence in field pea; preemergence treatments of metribuzin (0.46 kg a.i./ha), cyanazine (3.0 kg a.i./ha) and simazine (3.0 kg a,i./ha), and post-emergence treatments of simazine (2.0 kg a.i./ha) and diflufenican (0.2 kg a.i./ha), in lupin. Faba bean cv. Fiord tolerated pre-emergence treatments of terbutryne (2.0 kg a.i./ha), prometryne (3.0 kg a.i./ha) and triallate (1.6 kg a.i./ha), and there was seasonal variation in faba bean tolerance to pre-emergence treatment with cyanazine (3 kg a.i./ha), metribuzin (0.42 kg a.i./ha) and simazine (2.0 kg a.i./ha). The crops tolerated the early post-emergence grass herbicides: clethodim (0.48 kg a.i./ha), diclofop-methyl (1.5 kg a.i./ha), fluazifop-P (0.21 kg a.i./ha), haloxyfop (0.156 kg a.i./ha), quizalofop (0.28 kg a.i./ha), sethoxydim (0.372 kg a.i./ha). Herbicides that were tested in field pea and found to have only marginal selectivity at the recommended rate (even though some cultivars were tolerant) were terbutryne + MCPA (0.4 + 0.15 kg a.i./ha), diuron (0.4 kg a.i./ha) and pyridate (1.35 kg a.i./ha). Pyridate was non-selective in canola, lupin and faba bean. Faba bean tolerance to glyphosate (0.18 kg a.i./ha) was achieved in 1989 if application was delayed from 11 to 15 weeks after sowing.