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Late Glyphosate Applications Alter Yield and Yield Components in Glyphosate-Resistant Canola (Brassica napus)

  • Eric Tozzi (a1), K. Neil Harker (a2), Robert E. Blackshaw (a3), John T. O'Donovan (a2), Stephen E. Strelkov (a2) and Christian J. Willenborg (a1)...

Abstract

The development of glyphosate-resistant canola has provided improved weed-management options for growers, but crop tolerance to glyphosate may be inadequate at later growth stages. In this study, glyphosate-resistant canola 45H28 (RR) was used to determine the effects of glyphosate application timing on yield and yield components at several sites in western Canada. Canola received a single glyphosate applications at the two-leaf, six-leaf, bolting, and early bloom stages and sequential applications at the two-leaf + six-leaf, two-leaf + bolting, and two-leaf + early bloom stages. Contrasts were made between early vs. late, single vs. sequential, and on-label (two to six-leaf stage) vs. off-label (above six-leaf stage). In general, differences between application timings were observed for yield and yield components in 3 of 8 site-yr. Off-label applications of glyphosate (later than six-leaf) significantly decreased yield, seeds per pod, and increased thousand-seed weight and aborted pods in canola at the Lethbridge and St. Albert locations. Increased glyphosate translocation because of adequate, but not excessive, moisture to new growth may have suppressed new seed formation and encouraged pod abortion at the time of application in the 2010 and 2011 seasons. Results from this experiment demonstrate the importance of proper application timing of glyphosate on canola and can help better predict the effects of late applications.

El desarrollo de colza resistente a glyphosate ha brindado más opciones de manejo de malezas para los productores. En este estudio, se usó colza resistente a glyphosate 45H28 (RR) para determinar los efectos del momento de aplicación de glyphosate sobre el rendimiento y los componentes del rendimiento, en varios sitios en el oeste de Canada. La colza recibió una aplicación sencilla en los estadios de dos hojas, seis hojas, producción de tallo floral, y floración temprana y aplicaciones secuenciales en los estadios de dos hojas + seis hojas, dos hojas + producción de tallo floral, y dos hojas + floración temprana. Se realizaron contrastes entre las aplicaciones temprana vs. tardía, sencilla vs. secuencial, y dentro de las recomendaciones de la etiqueta (estadios de dos a seis hojas) vs. fuera de las recomendaciones de la etiqueta (después del estadio de seis hojas). En general, se vieron diferencias entre momentos de aplicación en el rendimiento y los componentes del rendimiento en 3 de los 8 sitios-años. Aplicaciones de glyphosate fuera de la etiqueta disminuyeron significativamente los rendimientos, el número de semillas por vaina, e incrementaron el peso de mil semillas y las vainas abortadas en colza en las localidades de Lethbridge y St. Albert. La precipitación excesiva podría haber causado una reducción en el rendimiento en la temporada 2012. Una translocación aumentada de glyphosate hacia tejidos de crecimiento nuevo, debido a una humedad adecuada, más no excesiva, podría haber prevenido la formación de semilla nueva y promovido el aborto de vainas al momento de aplicación en las temporadas 2010 y 2011. Los resultados de este experimento muestran la importancia de la aplicación de glyphosate en el momento adecuado en la colza y ayudan a predecir mejor los efectos de aplicaciones tardías.

Copyright

Corresponding author

Corresponding author's E-mail: chris.willenborg@usask.ca.

References

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Anonymous (2006) CanolaFact: Missing Pods or Blanks on the Main Stem! What Could Be the Cause? Winnipeg, MB: Canola Council of Canada. 5 pp
Barker, B (2007) Canola pod abortion investigated. Top Crop Manager 34:1617
Baucom, RS, Mauricio, R (2008) Constraints on the evolution of tolerance to herbicide in the common morning glory: resistance and tolerance are mutually exclusive. Evolution 62:28422854
Beckie, HJ, Harker, KN, Légère, A, Morrison, MJ, Séguin-Swartz, G, Falk, KC (2011) GM Canola: the Canadian experience. Farm Policy J 8:4349
Clayton, GW, Harker, KN, O'Donovan, JT, Baig, MN, Kidnie, MJ (2002) Glyphosate timing and tillage system effects on glyphosate-resistant canola (Brassica napus). Weed Technol 16:124130
Din, J, Khan, SU, Ali, I, Gurmani, AR (2011) Physiological and agronomic response of canola varieties to drought stress. J Anim Plant Sci 21:7882
Krausz, RF and Young, BG (2001) Response of glyphosate-resistant soybean (Glycine max) to trimethylsulfonium and isopropylamine salts of glyphosate. Weed Technol 15:745749
Main, CL, Jones, MA, Murdock, EC (2007) .Weed response and tolerance of enhanced glyphosate-resistant cotton to glyphosate. J Cotton Sci 11:104109
Martin, SG, Van Acker, RC, Friesen, LF (2001) Critical period of weed control in spring canola. Weed Sci 49:326333
Norsworthy, JK (2004) Tolerance of a glyphosate-resistant soybean to late-season glyphosate applications. Weed Technol 18:454457
Pline, WA, Edmisten, KL, Oliver, T, Wilcut, JW, Wells, R, Allen, HS (2002a) Use of digital image analysis, viability stains, and germination assays to estimate conventional and glyphosate-resistant cotton pollen viability. Crop Sci 42:21932200
Pline, WA, Viator, R, Wilcut, JW, Edmisten, KL, Thomas, J, Wells, R (2002b) Reproductive abnormalities in glyphosate-resistant cotton caused by lower CP4-EPSPS levels in the male reproductive tissue. Weed Sci 50:438447
Pline, WA, Wilcut, JW, Duke, SO, Edmisten, KL, Wells, R (2002c) Tolerance and accumulation of shikimic acid in response to glyphosate applications in glyphosate-resistant and conventional cotton (Gossypium hirsutum L.). J Agric Food Chem 50:506512
Pline, WA, Edmisten, KL, Wilcut, JW, Wells, R, Thomas, J (2003) Glyphosate-induced reductions in pollen viability and seed set in glyphosate-resistant cotton and attempted remediation by gibberellic acid (GA3). Weed Sci 51:1927
Pline-Srnić, WA, Thomas, WE, Viator, RP, Wilcut, JW (2005) Effects of glyphosate application timing and rate on sicklepod (Senna obtusifolia) fecundity. Weed Sci 19:5561
SAS Institute (2013) SAS User's Guide. Version 9.3. Cary, NC: SAS Institute
[SMA] Saskatchewan Ministry of Agriculture (2015) Guide to Crop Protection. Pages 554 p
Schilling, BS, Harker, KN, King, JR (2006) Glyphosate can reduce glyphosate-resistant canola growth after individual or sequential applications. Weed Technol 20:825830
Smyth, SJ, Gusta, M, Belcher, K, Phillips, PBW, Castle, D (2011) Changes in herbicide use after adoption of HR canola in western Canada. Weed Technol 25:492500
Thomas, WE, Pline-Srnić, WA, Thomas, JF, Edmisten, KL, Wells, R, Wilcut, JW (2004) Glyphosate negatively affects pollen viability but not pollination and seed set in glyphosate-resistant corn. Weed Sci 52:725734
Young, BG, Young, JM, Gonzini, LC, Hart, SE, Wax, LM, Kapusta, G (2001) Weed management in narrow- and wide-row glyphosate resistant soybean (Glycine max). Weed Technol 15:112–12

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