Soltani, N., Shropshire, C., Cowan, T. and Sikkema, P. 2003. Tolerance of cranberry beans (Phaseolus vulgaris) to soil applications of s-metolachlor and imazethapyr. Can. J. Plant Sci. 83: 645-648. There is little information on the tolerance of cranberry beans to preplant incorporated (PPI) and preemergence (PRE) applications of s-metolachlor and imazethapyr, either alone or in tank mix combination, for selective weed control in cranberry beans in Ontario. Tolerance of two cranberry bean cultivars, Hooter and SVM Taylor, to PPI and PRE applications of s-metolachlor, imazethapyr and their tank mix combination at the label rate (1×) and twice the label rate (2×) were studied at two Ontario locations (Exeter and Ridgetown) in 2001 and 2002. There were no differences between the two cultivars in their responses to the herbicide treatments. PPI and PRE applications of s-metolachlor alone at the 1× and 2× rate had no effect on visual crop injury and no negative effect on plant height, dry weight and yield compared to the control. The PPI and PRE applications of imazethapyr at the 1× rate did not result in significant visual crop injury, and had no negative effect on bean height and dry weight, but at the 2× rate there was significant visual crop injury, a decrease in height with the PPI application and decreased dry weight with PPI and PRE applications. No negative effect on cranberry bean yield was observed with the application of imazethapyr at either the 1× or 2× rates. The PPI and PRE applications of the tank mix of s-metolachlor plus imazethapyr at the 1× rate did not result in significant visual crop injury or decreases in bean plant height or dry weight. At the 2× rate, there was significant visual crop injury, a decrease in bean plant height with PPI and PRE applications and decreased dry weight with the PPI application. The tank mix of s-metolachlor plus imazethapyr at the 1× rate had no effect on yield, but the PPI application at the 2× rate caused a decrease in yield at 1 of the 4 site-years. Les deux cultivars ont réagi de la même manière aux traitements. L'usage PPI et PRE du s-méto-lachlor aux deux taux d'application n'entraîne pas de dommages visibles à la culture et n'a aucune incidence négative sur la hauteur des plants, le poids sec ni le rendement, comparativement aux témoins. L'usage PPI et PRE d'imazéthapyr au taux 1× n'entraîne pas non plus de dommages visibles importants à la culture et n'a pas d'incidence négative sur la hauteur des plants ni sur le poids sec, mais au double du taux normal, on note d'importants dommages à la culture, les plants sont plus petits avec le traitement PPI et il y a réduction du poids sec avec les traitements PPI et PRE. Le rendement du haricot canneberge n'est affecté par l'imazéthapyr à aucun des deux taux d'application. L'usage PPI et PRE du mélange n'entraîne pas de dommages visibles importants ni de forte diminution de la hauteur des plants et du poids sec au taux d'application normal, mais au double de ce taux, on note des dommages visibles sensibles, une rédu...

Weed control in white beans is currently limited by the small number of registered herbicides. The tolerance of two white bean cultivars, ‘AC Compass’ and ‘OAC Thunder’, to various postemergence (POST) herbicides at the maximum use rate and twice the maximum use rate for soybean or corn was evaluated at two Ontario locations in 2001 and 2002. Generally, the two cultivars did not differ in their response to the POST herbicides. POST applications of imazamox plus fomesafen, imazamox plus bentazon, and cloransulam-methyl decreased plant height, shoot dry weight, and yield by as much as 29, 41, and 55%, respectively, and increased seed moisture content up to 3.9%. POST applications of thifensulfuron, chlorimuron, and bromoxynil decreased plant height as much as 57%, shoot dry weight by up to 71%, yield as much as 93% and increased seed moisture content up to 15.5%. Based on these results, AC Compass and OAC Thunder white beans do not possess sufficient tolerance to support the registration of imazamox plus bentazon, imazamox plus fomesafen, cloransulam-methyl, thifensulfuron, chlorimuron, and bromoxynil.

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.

This study was conducted to evaluate the tolerance of two black bean cultivars, AC Harblack and Midnight Black Turtle, to preplant incorporated (PPI) and preemergence (PRE) applications of S-metolachlor at 1.6 and 3.2 kg ai/ha, imazethapyr at 0.075 and 0.15 kg ai/ha, and S-metolachlor plus imazethapyr at 1.6 plus 0.075 and 3.2 plus 0.15 kg ai/ha, respectively, at Exeter and Ridgetown, Ontario, Canada, in 2001 and 2002. There were generally no differences between the two cultivars in their responses to the herbicide treatments. PPI and PRE applications of S-metolachlor did not reduce black bean growth or yield. The PPI and PRE applications of imazethapyr alone or in tank mixture with S-metolachlor at the low and high rates did not have a significant effect on plant height, dry weight, seed moisture content, or yield at Ridgetown but caused as much as 14% visual crop injury at Exeter and reduced plant height, dry weight, and yield as much as 25, 40, and 49%, respectively. The higher rate of either herbicide alone or in tank mixture generally caused greater crop injury than the lower rate. At sites where there was a significant difference, the PPI application caused less crop injury than the PRE application. On the basis of these results, the PPI and PRE applications of S-metolachlor can be applied safely at the recommended label rate for the control of annual grass in black beans. However, the PPI and the PRE applications of imazethapyr alone and in tank mixture with S-metolachlor require careful application to avoid spray overlaps because there is potential for crop injury and yield reduction under some environmental conditions.

There is little information on the efficacy of mesotrione for the control of broadleaved weeds in spring planted cereals under Ontario environmental conditions. A total of eight studies were conducted in Ontario over a twoyear period (2010 to 2011) to evaluate cereal tolerance and weed control efficacy of mesotrione applied preemergence (PRE) at 25, 50, 100, 140, and 280 g ai ha −1 in spring planted barley, durum wheat, oats, and wheat. Mesotrione, applied preemergence at the rates evaluated, caused no injury in either year in spring planted barley, durum wheat, oats, or wheat evaluated at 1, 2 and 4 week after emergence (WAE). The predicted mesotrione rate required to give adequate control of AMBEL, CHEAL, POLCO and SINAR was generally greater than 280 g ai ha −1 . The average yield of the weedy check was 81% of the weed-free check. According to the exponential to maximum regression, the mesotrione rates required to give 90%, 95% and 98% of the weed-free check were 15, 30 and 45 g ai ha −1 , respectively. To provide yield equivalent to the standard treatment of bromoxynil/MCPA, 36 g ai ha −1 of mesotrione was needed. Based on these results, mesotrione applied preemergence at 25, 50, 100, 140, and 280 g ai ha −1 can be safely used in spring planted barley, durum wheat, oats, and wheat. However, greater than 280 g ai ha −1 of mesotrione was needed to adequately control AMBEL, CHEAL, POLCO and SINAR.

Sikkema, P., Soltani, N., Shropshire, C. and Cowan, T. 2004. Sensitivity of kidney beans (Phaseolus vulgaris) to soil applications of S-metolachlor and imazethapyr. Can. J. Plant Sci. 84: 405-407. Tolerance of Montcalm and Redhawk kidney beans to preplant incorporated (PPI) and preemergence (PRE) applications of S-metolachlor, imazethapyr and their tank mix at the maximum label rate in soybeans (1×) and twice that rate (2×) was studied at two Ontario locations (Exeter and Ridgetown) in 2001 and 2002. There were no differences between the two cultivars in their responses to the herbicide treatments. Visual evaluations of crop injury never exceeded 2% for any herbicide treatment. With the exception of a 7% height reduction after the PPI application of imazethapyr plus S-metholachlor at the 2× rate, none of the other treatments reduced plant height, dry weight, seed moisture content or seed yield. At sites where there was a significant difference, the PRE application caused more crop injury than the PPI application. These results indicate that there is an acceptable margin of crop safety for PPI and PRE applications of S-metolachlor and imazethapyr alone and in tank mix combination in kidney beans in Ontario. Les deux cultivars réagissent de la même façon à l'usage des herbicides. L'évaluation visuelle des dommages aux cultures ne dépasse pas 2 %, quel que soit le traitement. Outre une baisse de 7 % de la hauteur des plants après le traitement IAP d'imazétaphyr mélangé au S-métolachlor, aucun traitement ne réduit la taille des plants, le poids sec, la teneur en eau des graines ni le rendement grainier. Aux endroits où l'on a noté une variation sensible, le traitement AAL cause plus de dommages que le traitement IAP. Ces résultats révèlent que les deux types de traitement laissent une marge de manoeuvre acceptable pour l'application de s-métolachlor, d'imazétaphyr ou de leur mélange aux cultures de haricot, en Ontario.

No abstract

A limited number of preplant (PP) herbicides are available for spring seeded cereals in Ontario. Six field trials were conducted at the Huron Research Station, Exeter, Ontario, over a two-year period (Exeter, 2010 and 2011) to evaluate glyphosate, prosulfuron, and glyphosate plus prosulfuron applied PP for weed management in spring seeded no-till barley, oats, and wheat. There was no injury in barley, oats, and wheat with glyphosate, prosulfuron, and glyphosate plus prosulfuron applied preplant at the rates evaluated at 1, 2, and 4 weeks after crop emergence. Prosulfuron provided 49–99% control of AMBEL, 28% or less control of CONAR, 31–94% control of POLCO, 49–98% control of SINAR, and 46–79% control of SONAR. Prosulfuron in combination with glyphosate provided 73–98% control of AMBEL, less than 43% control of CONAR, 39–94% control of POLCO, 63–98% control of SINAR, and 60–85% control of SONAR. Prosulfuron reduced density of AMBEL 76% and SINAR 93% but had no significant effect on density of CONAR, POLCO, or SONAR. Prosulfuron in combination with glyphosate reduced biomass of AMBEL as much as 96% and SINAR 98% but had no significant effect on biomass of CONAR, POLCO, or SONAR. Yield of barley, oats, and wheat was not affected with glyphosate, prosulfuron, and glyphosate plus prosulfuron at the rates evaluated.