Abstract
The efficacy of cymoxanil, Pulsan (oxadixyl + mancozeb + cymoxanil, 1:7:0.4) and Sandocur-M (oxadixyl + mancozeb + cymoxanil, 1:7:2) in controlling late blight was examined in potatoes (cv. ‘Alpha’). Nine oxadixyl-sensitive and seven oxadixyl-resistant isolates ofPhytophthora infestons from six countries were tested. ED90 values of cymoxanil ranged between 64 and 467 mg a.i./l. No relationship was observed between sensitivity to cymoxanil and sensitivity to oxadixyl. Isolate S6A (1305) from California was the most sensitive to cymoxanil (ED90 = 64 mg/l), whereas isolate R11 from Israel was the least sensitive (ED90 = 467 mg/l). Most isolates from Israel were less sensitive (ED90 = 151–467 mg/l) than isolates from Switzerland, the Netherlands, Ireland, Mexico or California (ED90 = 64–152 mg/l). Three-way mixtures of cymoxanil with mancozeb and oxadixyl were more inhibitory than cymoxanil alone, regardless of the isolate. Sandocur-M was, for most isolates, more effective than Pulsan. The correlation coefficient between sensitivity to cymoxanil and sensitivity to Sandocur-M was 0.67, while that between cymoxanil and Pulsan was 0.76.
Similar content being viewed by others
References
Bertrand, A., Ducret, J., Debourge, J.C. and Homère, D. (1977) Etude des propriétés d’une nouvelle famille de fongicides: les monoethyl phosphites. Caractéristiques physicochimiques et propriétés biologiques.Phytiat.-Phytopharm. 26:3–17.
Cohen, Y. (1986) Fungicides mixtures controlling late blight in potatoes.Meded. Fac. Landbouwwet. Rijksuniv. Gent 51:715–718.
Cohen, Y., Eyal, H. and Sheinboin, Y. (1985) Efficacy of cymoxanil in controlling metalaxyl-resistant isolates ofPhytophthora infestons andPseudoperonospora cubensis.in: Smith, I.M. [Ed.] Fungicides for Crop Protection, 100 Years of Progress. Monogr. 31, pp. 307–310. British Crop Protection Council, Croyden, England.
Cohen, Y. and Grinberger, M. (1987) Control of the metalaxyl-resistant causal agents of late blight in potato and tomato and downy mildew in cucumber by cymoxanil.Phytopathology 77:1283–1288.
Cohen, Y. and Samoucha, Y. (1984) Cross-resistance to four systemic fungicides in metalaxyl-resistant strainsof Phytophthora infestons andPseudoperonospora cubensis.pl. Dis. 68:137–139.
Denis, S.J. (1976) DPX-3217 for control of grape downy mildew and potato/tomato late blight.Proc. Am. phytopath. Soc. 3:324 (abstr.).
Douchet, J.P., Absi, M., Hay, S.J.P., Muntan, L. and Villani, A. (1977) European results with DPX 3217, a new fungicide for the control of grape downy mildew and potato late blight.Proc. 1977 British Crop Protection Conference, Pests and Diseases (Brighton, U.K.), PP. 535–540.
Eberhard, K. (1978) Vergleichende Untersuchungen über die Wirksamkeit von Systemfungiziden gegen Oomyzeten.Arch. Phytopath. PflSchutz 14:115–122.
Grabski, C. and Gisi, U. (1987) Quantification of synergistic interactions of fungicides againstPlasmopara andPhytophthora.Crop Prot. 6:64–71.
Klopping, H.L. and Delp, C.J. (1980) 2-Cyano-N-[(ethylamino) carbonyl]-2-(methoxyimino) acetamide, a new fungicide.J. agric. Fd Chem. 28:467–468.
Ray, A.A. [Ed.] (1982) PROBIT. SAS User’s Guide: Statistics. SAS Institute, Inc., Cary, NC.
Richards, B.L. Jr. and Delp, C.J. (1976) Fungicide, DPX-3217, for control of downy mildews and potato/tomato late blight.Proc. Am. phytopath. Soc. 3:288 (abstr.).
Samoucha, Y. and Cohen, Y. (1985) Efficacy of fosetyl-Al in controlling metalaxyl-sensitive and -resistant isolates ofPhytophthora infestons.Phytopathology 75:1384 (abstr.).
Samoucha, Y. and Cohen, Y. (1988) Control of metalaxyl-resistantPhytophthora infestons in potato by synergistic cymoxanil mixtures.Phytopathology 78 (in press).
Samoucha, Y. and Gisi, U. (1987) Systemicity and persistence of cymoxanil in mixture with oxadixyl and mancozeb againstPhytophthora infestans andPlasmopara viticola.Crop Prot. 6:393–398.
Serres, J.M. and Carraro, G.A. (1976) DPX-3217, a new fungicide for the control of grape downy mildew, potato late blight and otherPeronosporales.Meded. Fac. Landbouwwet. Rijksuniv. Gent 41:645–650.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Samoucha, Y., Cohen, Y. Sensitivity ofPhytophthora Infestans to cymoxanil. Phytoparasitica 16, 39–45 (1988). https://doi.org/10.1007/BF02979575
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF02979575