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Control of cucumber downy mildew with novel fungicidal mixtures of Oxathiapiprolin


The efficacy of four oxathiapiprolin (OXPT)-based, novel fungicidal mixtures against downy mildew in cucumber caused by Pseudoperonospora cubensis was examined in growth chambers. OXPT+chlorothalonil (CHT) mixed at weight ratio of 1 + 66.7; OXPT+ azoxystrobin (AZ) 1 + 10.3; OXPT+mandipropamid (MPD) 1 + 8.3; and OXPT+mefenoxam (MFX) 1 + 3, were compared with each other and with individual components. Mixtures performed better than all fungicides alone except for oxathiapiprolin. Of the four mixtures, OXPT+MFX outperformed the other treatments with the highest preventive, curative, translaminar, root treatment and seed treatment efficacies. Deployment in the field of such mixtures with reduced doses of oxathiapiprolin may lower the selection pressure imposed on P. cubensis and delay the buildup of subpopulations resistant to oxathiapiprolin.

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active ingredient


parts per million (by weight)


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effective dose


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dispersible concentrate


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soluble liquid concentrate


oil dispersion


minimal inhibitory concentration


  • Andreassi, I. I. J. L., Gutteridge, S., Pember, S. O., and Sweigard, J. A. 2013. Detection and screening method and materials useful in performance thereof. International Patent no. WO13/009971 World Intellectual Property, Geneva.

  • Belisle, R. J., Hao, W., Mckee, B., Manosalva, P. M., & Adaskaveg, J. E. (2017). Baseline sensitivities of new fungicides for Phytophthora cinnamomi causing avocado root rot in California. Phytopathology, 107, 182.

    Google Scholar 

  • Bittner, R., & Mila, A. (2016). Production of Phytophthora nicotianae isolates resistant to oxathiapiprolin. Phytopathology, 106, 76–76.

    Article  Google Scholar 

  • Bittner, R. J., & Mila, A. L. (2017). Efficacy and timing of application of oxathiapiprolin against black shank of flue-cured tobacco. Crop Protect., 93, 9–18.

    CAS  Article  Google Scholar 

  • Cohen, Y. (2015). The novel oomycide oxathiapiprolin inhibits all stages in the asexual life cycle of Pseudoperonospora cubensis - causal agent of cucurbit downy mildew. PLoS One, 10, e0140015.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  • Cohen, Y. (2017). Control of late blight and downy mildews with fungicidal mixtures of oxathiapiprolin. Phytoparasitica, 45, 264.

    Google Scholar 

  • Cohen, Y., Van den Langenberg, K. M., Wehner, T. C., Ojiambo, P. S., Hausbeck, M., Quesada-Ocampo, L. M., Lebeda, A., Sierotzki, H., & Gisi, U. (2015). Resurgence of Pseudoperonospora cubensis: The causal agent of cucurbit downy mildew. Phytopathology, 105, 998–1012.

    Article  Google Scholar 

  • Cohen, Y., Rubin, A. E., Ben Naim, Y., & Galperin, M. (2018). Control of basil downy mildew with oxathiapiprolin-based fungicides. Phytoparasitica, 43, 425.

    Google Scholar 

  • Elderfield, J. A. D., Lopez-Ruiz, F. J., van den Bosch, F., & Cunniffe, N. J. (2018). Using epidemiological principles to explain fungicide resistance management tactics: Why do mixtures outperform alternations? Phytopathology, 108, 803–817.

    Article  Google Scholar 

  • Gisi, U., & Cohen, Y. (1996). Resistance to phenylamide fungicides: A case study with Phytophthora infestans involving mating type and race structure. Annual Review of Phytopathology, 34, 549–572.

    CAS  Article  Google Scholar 

  • Gray, M. A., Hao, W., Forster, H., & Adaskaveg, J. E. (2018). Baseline sensitivities of new fungicides and their toxicity to selected life stages of Phytophthora species from citrus in California. Plant Disease, 102, 734–742.

    Article  Google Scholar 

  • Ji, P., & Csinos, A. S. (2015). Effect of oxathiapiprolin on asexual life stages of Phytophthora capsici and disease development on vegetables. Ann. App. Biol., 166, 229–235.

    CAS  Article  Google Scholar 

  • Kosman, E., & Cohen, Y. (1996). Procedures for calculating and differentiating synergism and antagonism in action of fungicide mixtures. Phytopathology, 86, 1263–1272.

    CAS  Google Scholar 

  • Levy, Y., Benderly, M., Cohen, Y., Gisi, U., & Bassand, D. (1986). The joint action of fungicides in mixtures: Comparison of two methods for synergy calculation. EPPO Bull., 16, 651–657.

    Article  Google Scholar 

  • Miao, J. Q., Cai, M., Dong, X., Liu, L., Lin, D., Zhang, C., Pang, Z. L., & Liu, X. L. (2016). Resistance assessment for oxathiapiprolin in Phytophthora capsici and the detection of a point mutation (G769W) in PcORP1 that confers resistance. Frontiers in Microbiology, 7, 615–620.

    Article  Google Scholar 

  • Miao, J., Dong, X., Chi, Y., Lin, D., Chen, F., Du, Y., Liu, P., & Liu, X. (2018). Pseudoperonospora cubensis in China: Its sensitivity to and control by oxathiapiprolin. Pesticide Biochem. Physiol., 147, 96–101.

    CAS  Article  Google Scholar 

  • Olaya, G., Linley, R., Edlebeck, K., Kousik, S., & Kuhn, P. (2016). Oxathiapiprolin baseline sensitivity distribution of Phytophthora capsici isolates. Phytopathology, 106, 76.

    Article  Google Scholar 

  • Pasteris, R. J., Hanagan, M. A., and Shapiro, R. 2008. World Patent Appl. WO 2,008,013,925.

  • Pasteris, R. J., Hanagan, M. A., Bisaha, J. J., Finkelstein, B. L., Hoffman, L. E., Gregory, V., Andreassi, J. L., Sweigard, J. A., Klyashchitsky, B. A., Henry, Y. T., & Berger, R. A. (2016). Discovery of oxathiapiprolin, a new oomycete fungicide that targets an oxysterol binding protein. Biorg. Med. Chem., 24, 354–361.

    CAS  Article  Google Scholar 

  • Thomas, A., Neufeld, K. N., Seebold, K. W., Braun, C. A., Schwarz, M. R., & Ojiambo, P. S. (2018). Resistance to fluopicolide and propamocarb and baseline sensitivity to ethaboxam among isolates of Pseudoperonospora cubensis from the eastern United States. Plant Disease, 102, 1619–1626.

    Article  Google Scholar 

  • Weber-Boyvat, M., Zhong, W. B., Yan, D. G., & Olkkonen, V. M. (2013). Oxysterol-binding proteins: Functions in cell regulation beyond lipid metabolism. Biochemical Pharmacology, 86, 89–95.

    CAS  Article  Google Scholar 

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Correspondence to Yigal Cohen.

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The authors declare that they have no conflict of interest. This study complies with the ethical requirements of Phytoparasitica as appear in the Instructions to Authors.

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Cohen, Y., Rubin, A.E. & Galperin, M. Control of cucumber downy mildew with novel fungicidal mixtures of Oxathiapiprolin. Phytoparasitica 46, 689–704 (2018).

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  • Cucurbits
  • Fungicides
  • Mefenoxam
  • Oomycetes
  • Oxysterol binding proteins
  • Orondis
  • Resistance to fungicides
  • Zorvec