This paper summarises research trials conducted from 2010 to 2013 to determine speed of brownout and efficacy of an aminopyralid + metsulfuron-methyl herbicide product in pastures compared to metsulfuron alone and current commercial standards

Annetts, Robert A.

Elias, Natalie V.

Love, Christopher O.

Plater, Colin L.

Wells, Gregory S.

English

University of Kentucky

Control and management of weeds and diseases of grass and forage systems © 2013 Proceedings of the 22nd International Grassland Congress  1582 Aminopyralid + metsulfuron-methyl for cost-effective control of hard to kill pasture weeds  Gregory S Wells, Christopher O Love, Natalie V Elias, Colin L Plater and Robert A Annetts  Dow AgroSciences Australia Ltd, PO Box 838, Sunbury, Vic, 3429 Australia   Contact email: wells1@dow.com     Keywords: Aminopyralid, metsulfuron-methyl, efficacy, blackberry, gorse, galenia, artichoke thistle, brownout, control. Introduction This paper summarises research trials conducted from 2010 to 2013 to determine speed of brownout and efficacy of  an aminopyralid + metsulfuron-methyl herbicide product in pastures compared to metsulfuron alone and current commercial standards.  Methods Sites Trials were conducted in eastern Australia from Tenterfield, NSW to Bairnsdale, Victoria to collect data to support the registration of the aminopyralid + metsulfuron-methyl product concept. Formulations and adjuvants Aminopyralid + metsulfuron-methyl were applied either as a tank-mix or as a formulated pre-mix product.  Treatments were applied either with non-ionic surfactant at 0.1 to 0.2%v/v (artichoke thistle and blackberry) or silicone adjuvant at 0.2%v/v (galenia and gorse).  Commercial standard comparison treatments were applied at label recommended rates and adjuvant concentrations. Blackberry, gorse and artichoke thistle trials Efficacy trials were conducted either on commercial grazing properties or roadsides.  Treatments were applied by high volume handgun and applied to the point of runoff from the leaf surface.  Total spray volume applied was 1000 to 3000 L/ha, depending on weed size and density.  Each trial had 1 to 3 replicates, with a randomised complete block trial design (where replicated). Brownout scores were taken by subjective visual assessment at 25 to 76 days after application (DAA), using a 0 to 100 scale, where 100 = complete brownout.  Control scores were taken at 137 to 189 DAA, using a similar scale.  Further assessments are required to determine final control, 2 years after application. Galenia trials Efficacy trials were conducted on commercial farms, with treatments applied to naturally occurring weed infestations.  Treatments were applied with a hand-held small plot sprayer, with 3 m boom and nozzles at 50 cm spacings, to plots  that were 3 x 10 m in size.  Three or four  replicates were used in both trials, with randomised complete block trial design.  Application volume was 100 L/ha.    Table 1.  Artichoke thistle control (%) by high volume spray of either Aminopyralid + metsulfuron-methyl (Met) or metsulfuron-methyl (Met) alone. Treatment  Rate (g/100L) 103009 63DAA 113018 45DAA 113020 137DAA Aminopyralid + Met 5.6 + 4.5  80 a 98 a Aminopyralid + Met 7.5 + 6 99 a 87 a 100 a Met 6 80 b 43 b 73 b LSD (P=0.05)  2.9 7.5 6  Table 2.  Galenia brownout (34DAA) or control (189DAA) (%) by boomspray of either Aminopyralid + metsulfuron-methyl or metsulfuron-methyl alone. Treatment Rate (g/ha) 113006 Brown out 113007 Brown out 113006 control 113007 control Amino + Met 15 + 12 43 b 37 a 63 c 82 a Amino + Met 30 + 24 58 a 27 b 81 a 78 a Amino + Met 60 + 48 63 a 43 a 91 a 88 a Met 12 25 c 37 a 33 d 50 b LSD (P=0.05)  9.6 8.8 6.5 13.6  Table 3.  Gorse brownout (%) by high volume spray of either Aminopyralid + metsulfuron-methyl or metsulfuron-methyl alone.   Treatment  Rate (g/100 L) 113021 63DAA 113022 76DAA Amino + Met 11.3 + 9 99 a 100 a Met 9 80 b 85 b LSD(P=0.05)  1.5 6.5  Results Aminopyralid + metsulfuron-methyl provided artichoke thistle, galenia, gorse and blackberry brownout or control similar to or greater than metsulfuron (Tables 1, 2, 3, 4, and 5).  Conclusion Aminopyralid + metsulfuron-methyl gave similar or better brownout and control of blackberry, gorse, galenia and artichoke thistle as metsulfuron-methyl alone.  This new product is a new option for cost-effective control of a broad spectrum of weeds in Australia pastures. Wells et al. © 2013 Proceedings of the 22nd International Grassland Congress  1583 Table 4.  Blackberry brownout (%) by high volume spray of  Aminopyralid + metsulfuron-methyl or metsulfuron-methyl alone. Treatment  Rate (g/100L) 104014 25DAA 113001 35DAA 113003 47DAA 112001 56DAA 112004 29DAA 12005 27DAA Amino + Met Met 7.5+6 6 65 a 15 b 80 a 20 b 80 a 50 b 43 a 23 b 60 a 10 b 68 a 21 b LSD (P=0.05)  50 26 13 6.5 0 12.3  Table 5.  Blackberry control (%) by high volume spray of Aminopyralid + metsulfuron-methyl or metsulfuron-methyl alone. Treatment  Rate (g/100L) 104014 685DAA 113001 222DAA 113003 364DAA 113002 364DAA 112001 301DAA Amino+ Met Met 7.5+6 6 90 b 35 a 90 a 85 a 95 a 94 a 100 90 100 b 100 b LSD (P=0.05)  43 13 7 *(1 rep only) 0   

Aminopyralid + Metsulfuron-Methyl for Cost-Effective Control of Hard to Kill Pasture Weeds

https://uknowledge.uky.edu/cgi/viewcontent.cgi?article=1770&amp;context=igc

Aminopyralid + Metsulfuron-Methyl for Cost-Effective Control of Hard to Kill Pasture Weeds

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