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Five field trials were conducted over a 2-yr period (2007, 2008) at various locations in Ontario to evaluate the tolerance of black, cranberry, kidney, otebo, pink, pinto, small red Mexican (SRM), and white bean to halosulfuron applied PPI, PRE, and POST at 35 and 70 g ai/ha. There was minimal injury (3% or less) with halosulfuron applied PPI or PRE in dry bean. At Exeter and Ridgetown, halosulfuron applied POST at 35 and 70 g/ha caused 3 to 5% and 4 to 8% injury in dry bean, respectively at 1 wk after herbicide application (WAA). The injury was transient with no significant injury at 2 and 4 WAA. At Harrow, halosulfuron POST at 35 and 70 g/ha caused as much as 4% injury at 35 g/ha and 14% injury at 70 g/ha in dry bean. Halosulfuron applied PPI, PRE, and POST at 35 and 70 g/ha caused no decrease in plant height of dry bean except for kidney bean, which was reduced 6% at 70 g/ha, and white bean, which was reduced 3% at both 35 and 70 g/ha. Halosulfuron applied PPI, PRE, and POST at 35 and 70 g/ha caused no decrease in dry bean yield except for kidney bean, which was reduced 9% at 35 g/ha and 10% at 70 g/ha; otebo bean, which was reduced 3% at 70 g/ha; and white bean, which was reduced 7% at both 35 and 70 g/ha. On the basis of these results, there is an adequate margin of crop safety in dry bean to halosulfuron applied PPI or PRE at 35 and 70 g/ha. In addition, there is an adequate margin of crop safety in black, cranberry, pink, pinto, and SRM bean to halosulfuron applied POST at 35 and 70 g/ha. However, further research is required to ascertain the tolerance of kidney, otebo, and white bean to halosulfuron applied POST.

Three field trials were conducted over a 2-yr period (2004 and 2005) at Exeter and Ridgetown, Ontario to evaluate the tolerance of eight market classes of dry beans to KIH-485 applied PRE at 210 and 420 g ai/ha. KIH-485 PRE caused as much as 67% visual injury in small-seeded and 44% visual injury in large-seeded dry beans. KIH-485 applied PRE at 420 g/ha reduced plant height up to 47% at Ridgetown and 8% at Exeter in 2004, and reduced height of brown and white bean by 15 and 19%, respectively, but had no effect on the height of the other beans in 2005. Shoot dry weight was not affected at Exeter in 2004 but was reduced by 46% at Ridgetown in 2004 and 14% at Exeter in 2005. In 2004, seed moisture content increased by 5, 6, and 12% in black, otebo, and pinto beans, respectively. Seed yield was reduced up to 27% at Ridgetown and 11% at Exeter in 2004 but was not affected at Exeter in 2005. On the basis of this research, KIH-485 PRE causes unacceptable injury in some dry bean market classes. Nomenclature: KIH...

Three field trials were established from 2001 to 2003 in Ontario to determine the effect of foramsulfuron POST (35 and 70 g ai/ha), isoxaflutole PRE (105 and 210 g ai/ha), and isoxaflutole plus atrazine PRE (105 + 1063 and 210 + 2126 g ai/ha) applied in the previous years to field corn on cranberry, black, kidney, and white (navy) bean. Foramsulfuron residues did not cause visible injury, or reductions in shoot dry weight or yield of dry bean 1 yr after application in corn. In contrast, visual injury across the four market classes varied from 4 to 37% 1 yr after application of isoxaflutole, and from 30 to 54% 1 yr after application of isoxaflutole plus atrazine. Isoxaflutole residues reduced shoot dry weight and yield as much as 81 and 44% in cranberry, 52 and 39% in black, 53 and 19% in kidney, and 42 and 19% in white bean, respectively. Isoxaflutole plus atrazine residues reduced shoot dry weight and yield as much as 87 and 64% in cranberry, 75 and 61% in black, 71 and 46% in kidney, and 65 and 33% in white navy bean, respectively. Injury was not detected regardless of market classes 2 yr after application of isoxaflutole alone or in tank mix with atrazine. Based on these results, it is recommended that none of the market classes of dry bean tested in this study should be grown 1 year after an application of isoxaflutole or isoxaflutole plus atrazine. A recropping interval of 2 years is currently recommended following applications of isoxaflutole or isoxaflutole plus atrazine for these market classes of dry bean.

There is little information on the sensitivity of dry beans to flumioxazin. Tolerance of eight cultivars of dry beans representing four market classes (black, cranberry, kidney, and white beans) to preplant incorporated (PPI) and preemergence (PRE) applications of flumioxazin at the rate of 52.5, 70, and 140 g ai/ha were studied in three field experiments in Ontario in 2002 and 2003. There were no differences (P < 0.05) between two cultivars within a market class in their responses to flumioxazin. However, the four market classes differed in their responses to flumioxazin. Black and white beans were more sensitive to the PRE application of flumioxazin than cranberry and kidney beans. Flumioxazin applied PRE at 140 g/ha caused as much as 34% visual injury and reduced plant height by 23 to 28%, shoot dry weight by 35 to 39%, and yield by 20 to 30% in black and white bean market classes. Flumioxazin-applied PPI did not injure any market class. On the basis of this research, there is an acceptable margin of crop safety in these black and white bean cultivars only when flumioxazin is applied PPI. The two cranberry and kidney bean cultivars were tolerant to all rates of flumioxazin applied both PPI and PRE.

White bean producers have a limited number of herbicide options available for annual grass and broadleaf weed control. Tolerance of two white bean cultivars to preemergence (PRE) applications ofS-metolachlor,S-metolachlor + imazethapyr, flumetsulam +S-metolachlor, cloransulam-methyl, clomazone, clomazone + imazethapyr, and clomazone +S-metolachlor at the maximum labeled rate in soybean (1×) and twice the labeled rate (2×) were studied at two Ontario locations (Exeter and Ridgetown) in 2001 and 2002.S-Metolachlor, clomazone, and clomazone +S-metolachlor generally had no negative effect on plant height, dry weight, maturity, and yield.S-Metolachlor + imazethapyr and clomazone + imazethapyr reduced plant height, dry weight, and yield as much as 21, 42, and 24%, respectively. Flumesulam +S-metolachlor and cloransulam-methyl reduced plant height, dry weight, and yield as much as 39, 58, and 43%, respectively. White beans are tolerant to PRE applications ofS-metolachlor, clomazone, and clomazone +S-metolachlor. White beans are sensitive to PRE applications ofS-metolachlor + imazethapyr, flumetsulam +S-metolachlor, clomazone + imazethapyr, and cloransulam-methyl.

Field and laboratory studies were conducted to determine if differences existed in pinto bean varietal toler- ance to postemergence application of imazethapyr under field conditions; if differences in tolerance were due to differ- ential acetolactate synthase enzyme sensitivity or differences in 14C-imazethapyr absorption, translocation, and metabo- lism; and the heritability of inazethapyr tolerance in pinto bean. All rates of imazethapyrinjured Olathe, Sierra, UI-114, P89405, Aztec, and P90570 pinto bean varieties 7 d after treatment in 1991 and 1992, except 53 g ai ha-1 of imaze- thapyr applied to Sierra pinto bean in 1991. Olathe was injured more than other varieties in 1991, and physiological maturity of Olathe was delayed more than Sierra in 1991 and 1992. Seed yields of all varieties were not reduced in 1991, and only P90570 had reduced seed yields from 53 g ha-' of imazethapyr in 1992. Differential sensitivity of the acetolac- tate synthase enzyme to imazethapyr was not the mechanism of differential varietal response. Olathe pinto bean absorbed and translocated 1.4 and 1.3 times more 14C-imazethapyr, respectively, than Sierra pinto bean 24 h after application. No differences in 14C-imazethapyr metabolism were detected between Olathe and Sierra pinto bean. Broad heritability of inazethapyr tolerance in pinto bean was calculated to be 0.85. The number of genes controlling the inheritance of inazethapyr tolerance in pinto bean was greater than one. Nomenclature: Imazethapyr, 2-(4,5-dihydro-4-methyl-4- methyl-4-(1-methylethyl)-5-oxo-lH-imidazol-2-yl)-5-ethyl