Selecting a preemergence (PRE) and postemergence (POST) herbicide program that has the greatest efficacy can be difficult for corn producers and is highly dependent on weed spectrum. Weather conditions before and after herbicide application can further complicate decisions because they influence herbicide efficacy. Eleven field trials were conducted at three locations in Southwestern Ontario from 2003 to 2006, to determine the most effective PRE and POST corn herbicides for weed control. The most abundant weed species across all locations were redroot pigweed ( Amaranthus retroflexus L.), common ragweed ( Ambrosia artemisiifolia L.), common lambsquarters ( Chenopodium album L.), and green foxtail ( Setaria viridis (L.) Beauv.). Nine PRE herbicide treatments and eleven POST (applied at the 3-4 leaf stage of corn) herbicide treatments were tested. Results from this study suggest that the timing and amount of precipitation influence herbicide efficacy. For example, precipitation levels 0-17 mm within seven days after herbicide application (PRE or POST) provided unacceptable weed control in treatments that included atrazine, dimethenamidp, isoxa-flutole/atrazine or S-metolachlor/benoxacor. Cumulative precipitation during the 14 days after PRE application that exceeded the monthly average (by at least 64%) reduced Setaria viridis control with pendimethalin. This study demonstrates that a better understanding of how environmental conditions, especially precipitation affect herbicide efficacy, need to be considered by growers when selecting a corn herbicide program to reduce the possibility of weed control failure.
G. R. Armel, H. P. Wilson, R. J. Richardson and T. E. Hines, “Mesotrione, Acetochlor, and Atrazine for Weed Management in Corn (Zea mays),” Weed Technology, Vol. 17, No. 2, 2003, pp. 284-290. doi:10.1614/0890-037X(2003)017[0284:MAAAFW]2.0.CO;2
J. A. Bond and J. L. Griffin, “Weed Control in Corn (Zea mays) with an Imazethapyr plus Imazapyr Prepackaged Mixture,” Weed Technology, Vol. 19, No. 4, 2005, pp. 992-998. doi:10.1614/WT-04-267R1.1
A. R. Isensee and A. M. Sadeghi, “Effects of Tillage and Rainfall on Atrazine Residue Levels in Soil,” Weed Science, Vol. 42, No. 3, 1994, pp. 462-467.
D. J. Lyon and R. G. Wilson, “Chemical Weed Control in Dryland and Irrigated Chickpea,” Weed Technology, Vol. 19, No. 4, 2005, pp. 959-965. doi:10.1614/WT-05-013R.1
C. L. Stewart, R. E. Nurse, A. S. Hamill and P. H. Sikkema, “Environment and Soil Conditions Influence Pre- and Post-Emergence Herbicide Efficacy in Soybean,” Weed Technology, Vol. 24, No. 3, 2010, pp. 234-243. doi:10.1614/WT-09-009.1
M. A. Ferrell, T. D. Whitson and S. D. Miller, “Basic Guide to Weeds and Herbicides,” The University of Wyoming, College of Agriculture, Department of Plant Sciences, Cooperative Extension Service, MP18, 2004, pp. 1-19.
C. A. Damalas, and I. G. Eleftherohorinos, “Dicamba and Atrazine Antagonism on Sulfonylurea Herbicides Used for Johnsongrass (Sorghum halepense) Control in Corn (Zea mays),” Weed Technology, Vol. 15, No. 1, 2001, pp. 62-67. doi:10.1614/0890-037X(2001)015[0062:DAAAOS]2.0.CO;2
D. L. Jordan, R. E. Frans and M. R. McClelland, “Interactions of DPXPE350 with fluazifop-P, Sethoxydim, Clethodim, and Quizalofop-P,” Weed Technology, Vol. 7, 1993, pp. 605-610.
W. A. Pline, J. W. Wilcut and K. L. Edmisten, Postemergence Weed Control in Soybean (Glycine max) with Cloransulam-Methyl and Diphenyl Ether Tank-Mixtures,” Weed Technology, Vol. 16, No. 4, 2002, pp. 737-742. doi:10.1614/0890-037X(2002)016[0737:PWCISG]2.0.CO;2
A. J. Chomas and J. J. Kells, “Triazine-Resistant Common Lambsquarters (Chenopodium album) Control in Corn with Preemergence Herbicides,” Weed Technology, Vol. 18, No. 3, 2004, pp. 551-554. doi:10.1614/WT-03-077R
M. M. Loux, A. F. Dobbels, W. G. Johnson, G. R.W Nice, T. T Bauman and J. M. Stachler, “Weed Control Guide for Ohio and Indiana,” Ohio State University Extension Bulletin 789/Purdue Extension Pub No. WS16, 2008, 201 p.
C. M. Whaley, G. R. Armel, H. P. Wilson and T. E. Hines, “Comparison of Mesotrione Combinations with Standard Weed Control Programs in Corn,” Weed Technology, Vol. 20, No. 3, 2006, pp. 605-611. doi:10.1614/WT-05-042R1.1
A. Hager and K. Renner, “Common Ragweed (Ambrosia artemisiifolia) Control in Soybean (Glycine max) with Bentazon as Influenced by Imazethapyr or Thifensulfuron Tank-Mixes,” Weed Technology, Vol. 8, No. 4, 1994, pp. 766-771.
S. A. Gower, M. M. Loux, J. Cardina and S. K. Harrison, “Effect of Planting Date, Residual Herbicide, and Postemergence Application Timing on Weed Control and Grain Yield in Glyphosate-Tolerant Corn (Zea mays),” Weed Technology, Vol. 16, No. 3, 2002, pp. 488-494. doi:10.1614/0890-037X(2002)016[0488:EOPDRH]2.0.CO;2
F. J. Muehlbauer, R. J. Summerfield, W. J. Kaiser, S. L. Clement, C. M. Boerboom, M. M. Welsh-Maddux and R. W. Short, “Principles and Practice of Lentil Production,” 1998, Accessed on 1 June 2012. http://www.ars.usda.gov/is/np/lentils/lentils.htm?pf51
I. Riethmuller-Haage, L. Bastiaans, C. Kempenaar, V. Smunty and M. J. Kropff, “Are Pre-Spraying Growing Conditions a Major Determinant of Herbicide Efficacy?” Weed Research, Vol. 47, No. 5, 2007, pp. 415-424. doi:10.1111/j.1365-3180.2007.00584.x
D. D. Buhler, “Early Preplant Atrazine and Metolachlor in Conservation Tillage Corn (Zea mays),” Weed Technology, Vol. 5, 1991, pp. 66-71.
D. D. Buhler and V. L. Werling, “Weed Control from Imazaquin and Metolachlor in No-Till Soybeans (Glycine max),” Weed Science, Vol. 37, 1989, pp. 392-399.
K. M. Novosel, K. A Renner, J. J. Kells and E. Spandl, “Metolachlor Efficacy as Influenced by Three Acetolactate Synthase-Inhibiting Herbicides,” Weed Technology, Vol. 12, 1998, pp. 248-253.
F.P. Salzman and K. A. Renner, “Response of Soybean to Combinations of Clomazone, Metribuzin, Linuron, Alachlor, and Atrazine,” Weed Technology, Vol. 6, 1992, pp. 922-929.
W.A Bailey, H. P. Wilson and T. E. Hines, “Influence of Cultivation and Herbicide Programs on Weed Control and Net Returns in Potato (Solanum tuberosum),” Weed Technology, Vol. 15, No. 4, 2001, pp. 654-659. doi:10.1614/0890-037X(2001)015[0654:IOCAHP]2.0.CO;2
J. P. Kelley and T. F. Peeper, “MON 37500 Application Timing Affects Cheat (Bromus secalinus) Control and Winter Wheat,” Weed Science, Vol. 51, No. 2, 2003, pp. 231-236. doi:10.1614/0043-1745(2003)051[0231:MATACB]2.0.CO;2
P. Sikkema, W. Deen and S.Vyas, “Weed Control in Pea with Reduced Rates of Imazethapyr Applied Preemergence and Postemergence,” Weed Technology, Vol. 19, No. 1, 2005, pp. 14-18. doi:10.1614/WT-03-051R3
C. M. Boerboom, D. E. Stolenberg, M. R. Jeschke, T. L. Trower and J. M. Gaska, “Factors Affecting Glyphosate Control of Common Lambsquarters,” North Central Weed Science Society Proceeding, Vol. 61, 2006, p. 54.
K. N. Reddy and M. A. Locke, “Imazaquin Spray Retention, Foliar Washoff Andrunoff Losses under Simulated Rainfall,” Pesticide Science, Vol. 48, No. 2, 1996, pp. 179-187. doi:10.1002/(SICI)1096-9063(199610)48:2 3.0.CO;2-M
Anonymous, “Frontier? Herbicide Product Label,” Mississauga, ON, BASF Canada Inc., 2008, 17 p.
Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA), “Guide to Weed Control, Publication 75,” Toronto, ON, 2008, 379 p.
L. E. Steckel, C. L. Sprague and A. G. Hager, “Common Waterhemp (Amaranthus rudis) Control in Corn (Zea mays) with Single Preemergence and Sequential Applications of Residual Herbicides,” Weed Technology, Vol. 16, No. 4, 2002, pp. 755-761. doi:10.1614/0890-037X(2002)016[0755:CWARCI]2.0.CO;2
S. Taylor-Lovell, G. K. Sims, L. M. Wax and J. J. Hassett, “Hydrolysis and Soil Adsorption of the Labile Herbicide Isoxaflutole,” Environmental Science & Technology, Vol. 34, No. 15, 2000, pp. 3186-3190. doi:10.1021/es991382f
Y. Lee, H. Kim, J. Chung and B. Jeong, “Loss of Pendimethalin in Runoff and Leaching from Turfgrass Land under Simulated Rainfall,” Journal of Agricultural and Food Chemistry, Vol. 48, No. 11, 2000, pp. 5376-5382. doi:10.1021/jf0005869
K. E. Savage, “Persistence of Several Dinitroaniline Herbicides as Affected by Soil Moisture,” Weed Science, Vol. 26, 1978, pp. 465-471.
J. Li., W. G. Johnson and R. J. Smeda, “Interactions between Glyphosate and Imazethapyr on Four Annual Weeds,” Crop Protection, Vol. 21, No. 10, 2002, pp. 1087-1092. doi:10.1016/S0261-2194(02)00047-9
L. C. Gonzini, S. E. Hart and L. M. Wax, “Herbicide Combinations for Weed Management in Glyphosate-Resistant Soybean (Glycine max),” Weed Technology, Vol. 13, 1999, pp. 354-360.
R. E. Nurse, A. S. Hamill, C. J. Swanton, F. J. Tardif, W. Deen and P. H.Sikkema, “Is the Application of a Residual Herbicide Required Prior to Glyphosate Application in No-Till Glyphosate-Tolerant Soybean (Glycine max)?” Crop Protection, Vol. 26, No. 4, 2007, pp. 484-489. doi:10.1016/j.cropro.2006.04.018
S. A. Payne and L. R. Oliver, “Weed Control Programs in Drilled Glyphosate-Resistant Soybean,” Weed Technology, Vol. 14, No. 2, 2000, pp. 413-422. doi:10.1614/0890-037X(2000)014[0413:WCPIDG]2.0.CO;2
J. W. Barnes and L. R. Oliver, “Cloransulam Antagonizes Annual Grass Control with Aryloxyphenoxypropionate Graminicides but Not Cyclohexanediones,” Weed Technology, Vol. 18, No. 3, 2004, pp. 763-772. doi:10.1614/WT-03-181R
R. E. Nurse, C. J. Swanton., F. J. Tardif and P. H. Sikkema, “Weed Control and Yield Are Improved When Glyphosate Is Preceded by a Residual Herbicide in Glyphosate-Tolerant Maize (Zea mays),” Crop Protection, Vol. 25, No. 11, 2006, pp. 1174-1179. doi:10.1016/j.cropro.2006.02.015
Statistical Analysis Systems, “The SAS System for Windows,” Release 8.0, Statistical Analysis Systems Institute, Cary, 2000, 3884 p.
Anonymous, “Outlook? Herbicide Product Label,” BASF Corporation, Research Park Triangle, 2008, 17 p.
B. G. Young, S. E. Hart and F. W. Simmons, “Preemergence Weed Control in Conventional-Till Corn (Zea mays) with RPA 201772,” Weed Technology, Vol. 13, 1999, pp. 471-477.
C. L. Schuster, K. Al-Khatib and J. A. Dille, “Mechanism of Antagonism of Mesotrione on Sulfonylurea Herbicides,” Weed Science, Vol. 55, No. 5, 2007, pp. 429-434. doi:10.1614/WS-06-217.1
C. L. Schuster, K. Al-Khatib and J. A. Dille, “Efficacy of Sulfonylurea Herbicides When Tank Mixed with Mesotrione,” Weed Technology, Vol. 22, No. 2, 2008, pp. 222-230. doi:10.1614/WT-07-131.1
C. A. Morton and R. G. Harvey, “Simulated Environments Influence Primisulfuron Efficacy,” Weed Science, Vol. 42, 1994, pp. 424-429.