Sensitivity and resistance level of sourgrass population subjected to glyphosate application
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Department of Plant Protection, São Paulo State University (UNESP), Botucatu, São Paulo, Brazil
A - Research concept and design; B - Collection and/or assembly of data; C - Data analysis and interpretation; D - Writing the article; E - Critical revision of the article; F - Final approval of article
Jhonatan Diego Cavalieri   

Department of Plant Protection, São Paulo State University (UNESP), 18610-034, Botucatu, Brazil
Submission date: 2020-07-15
Acceptance date: 2020-10-16
Online publication date: 2021-02-23
Journal of Plant Protection Research 2021;61(1):47–56
The intensive use of glyphosate in agricultural areas has increased the frequency of weeds that are resistant to herbicides. Thus, this study was aimed to assess the sensitivity and resistance level of Digitaria insularis (L.) Fedde (sourgrass) populations to glyphosate. Sixtytwo sourgrass populations were collected from the states of Paraná and São Paulo, Brazil, and subjected to glyphosate application at 1,080 and 2,160 g of acid equivalent (a.e.) · ha–1 in screening assays. Five sourgrass populations were selected, three of which are resistant and two of which are susceptible to glyphosate, to determine the resistance factors (RFs) through dose-response studies at two phenological stages of plant growth: the 2–4-leaf stages and the 2–4-tiller stage. The trials were conducted in a greenhouse in accordance with a completely randomized design. In both trials, the control was evaluated based on the score of the visual control symptoms (VC) and the percentage of dry matter (DM) in relation to those of the control (without application). In the screening test, the data obtained for the response variables were adjusted for frequency curves by following the regression model proposed by Gompertz. The results indicated low sensitivity of D. insularis to glyphosate in 100% of the samples from areas in which soybeans are tolerant to this herbicide. Populations with susceptible plants were found in fallow areas, pasture areas and sugar cane fields. Based on the values of VC50 and DM50, the maximum RF obtained among the populations was 15. More advanced stages of development make sourgrass control difficult, requiring doses that are 3.5 times greater than those at the initial stage.
The authors wish to thank the National Council for Scientific and Technological Development (CNPq, Brazil, Grant no 159038/2013-8) for granting a scholarship to the first author and financial aid for the completion of the study.
The authors have declared that no conflict of interests exist.
Grant: CNPq, Brazil, Grant no 159038/2013-8
Asociación Latinoamericana De Malezas – ALAM. 1974. Recommendations on the unification of disease control evaluation. Journal of the Latin American Weed Association 1: 6–38. (in Spanish).
Burgos N.R., Tranel P.J., Streibig J.C., Davis V.M., Shaner D., Norsworthy J.K., Ritz C. 2013. Review: confirmation of resistance to herbicides and evaluation of resistance levels. Weed Science 61 (1): 4–20. DOI: https://doi.org/10.1614/WS-D-1....
Carvalho S.J.P., Lombardi B.P., Nicolai M., López-Ovejero R.F., Christoffoleti P.J., Medeiros D. 2005. Dose-response curves to evaluate the control of weed emergence fluxes by imazapic. Planta Daninha 23 (3): 535–542. DOI: http://dx.doi.org/10.1590/S010.... (in Portuguese).
Carvalho L.B., Hipólito H.C., Torralva F.G., Alves P.L.C.A., Christoffoleti P.J., De Prado R. 2011. Detection of sourgrass (Digitaria insularis) biotypes resistant to glyphosate in Brazil. Weed Science 59 (2): 171–176. DOI: https://doi.org/10.1614/WS-D-1....
Carvalho L.B., Alves P.L., González-Torralva F., Cruz-Hipolito H.E., Rojano-Delgado A.M., Prado R., Gil-Humanes J., Barro F., de Castro M.D. 2012. Pool of resistance mechanisms to glyphosate in Digitaria insularis. Journal of Agricultural and Food Chemistry 60 (2): 615–622. DOI: 10.1021/jf204089d.
Christoffoleti P.J. 2002. Rate-response curves of resistant and susceptible Bidens pilosa L. biotypes to als-inhibitor herbicides. Scientia Agricola 59 (3): 513–519. DOI: https://doi.org/10.1590/S0103-... (in Portuguese).
CONAB. 2018. National Supply Company. Monitoring the Brazilian harvest: grains, ninth survey. 2018. Available on: https://www.conab.gov.br/safra.... [Accessed: 10 February 2019].
CTNbio. 2019. National Technical Commission on Biosafety. Commercial Releases. Available on: http://ctnbio.mcti.gov.br/libe... BvU&p_p_lifecycle=0&p_p_state=normal U_fileEntryId=2061402#/liberacao comercial/consultar-processo. [Accessed: 01 January 2020] (in Portuguese).
Hall L.M., Stromme K.M., Horsman G.P. 1998. Resistance to acetolactate synthase inhibitors and quinclorac in a biotype of false cleavers (Galium spurium). Weed Science 46 (4): 390–396. DOI: https://doi.org/10.1017/S00431....
Heap I. 2020. Herbicide resistant sourgrass globally (Digitaria insularis). Available: <http://www.weedscience.org/Sum...>. [Accessed: 01 April 2020].
Gemelli A., Oliveira Jr. R.S., Constantin J., Braz G.B.P., Jumes T.M.C., Oliveira Neto A.M., Dan H.A., Biffe D.F. 2012. Biology aspects of Digitaria insularis resistant to glyphosate and implications for its control. Revista Brasileira de Herbicidas 11 (2): 231–240. DOI: https://doi.org/10.7824/rbh.v1... (in Portuguese).
Gompertz B. 1825. On the nature of the function expressive of the law of human mortality, and on a new mode of determining the value of life contingencies. Philosophical Transactions of the Royal Society of London 115: 513–583.
Kissmann K.G., Groth D. 1997. Weed and Harmful Plants. 3rd ed. Tomo I. São Paulo, Brazil, 606 pp.
Lopez Ovejero R.F., Takano H.K., Nicolai M., Ferreira A., Melo M.S.C., Cavenaghi A.L. 2017. Frequency and dispersal of glyphosate-resistant sourgrass (Digitaria insularis) populations across brazilian agricultural production areas. Weed Science 65 (2): 285–294. DOI: https://doi.org/10.1017/wsc.20....
Melo M.S.C., Rocha L.J.F.N., Brunharo C.A.C.G., Nicolai M., Tornisiello V.L., Nissen S.J., Christoffoleti P.J. 2019. Sourgrass resistance mechanism to the herbicide glyphosate. Planta Daninha. Viços. 37: e019185746. DOI: https://doi.org/10.1590/s0100-....
Mendonça G.S., Martins C.C., Martins D., Costa N.V. 2014. Ecophysiology of seed germination in Digitaria insularis (L.) Fedde. Revista Ciência Agronômica 45 (4): 823–832. DOI: https://doi.org/10.1590/S1806-....
Mondo V.H.V., Carvalho S.J.P., Dias A.C.R., Júlio M.F. 2010. Light and temperature effects on the seed germination of four Digitaria weed species. Revista Brasileira de Sementes. 32 (1): 131–137. DOI: https://doi.org/10.1590/S0101-... (in Portuguese).
Reinert C.S., Prado A.B.C.A., Christoffoleti P.J. 2013. Comparative dose-response curves between sourgrass (Digitaria insularis) resistant and susceptible biotypes to glyphosate. Revista Brasileira de Herbicidas 12 (3): 260–267. DOI: https://doi.org/10.7824/rbh.v1... (in Portugese).
Rodrigues B.N., Almeida F.S. 2018. Herbicide Guide. Londrina, PR, Brazil, 764 pp.
Sammons R.D., Gaines T.A. 2014. Glyphosate resistance: state of knowledge. Pest Management Science 70 (9): 1367–1377. DOI: 10.1002/ps.3743.
Seefeldt S.S., Jensen J.E., Fuerst E.P. 1995. Log-logistic analysis of herbicide dose-response relationships. Weed Technology 9 (2): 218–227. DOI: https://doi.org/10.1017/S08900....
Silveira H.M., Langaro A.C., Cruz R.A., Sediyama T., Silva A.A. 2018. Glyphosate efficacy on sourgrass biotypes with suspected resistance collected in GR-crop fields. Acta Scientiarum, Agronomy: 40. DOI: http://dx.doi.org/10.4025/acta....
SYSTAT. 2013. Systat Software Products. Available on: https://systatsoftware.com/pro.... [Accessed: 11 February 2019].
Souza R.T.I., Velini E.D., Palladini L. 2007. Methodological aspects for spray deposit analysis by punctual deposit determination. Planta Daninha 25 (1): 195–202. DOI: https://doi.org/10.1590/S0100-... (in Portuguese).
Takano H.K., Oliveira Jr. R.S., Constantim J., Mangolim C.A., Machado M.F.P.S., Bevilaqua M.R.R. 2018. Spread of glyphosate-resistant sourgrass (Digitaria insularis): Independent selections or merely propagule dissemination? Weed Biology and Manegement 18: 50–60. DOI: https://doi.org/10.1111/wbm.12....
USDA. 2018. United States Department of Agriculture – Brazil – Agricultural Biotechnology Report. Avaliable on: http://usdabrazil.org.br/en/re....>. [Accessed: 10 February 2019].