Comparison of Elemental Sulfur Products as Tank Mix Partners with Azoxystrobin for Management of Late Leaf Spot (Nothopassalora personata) of Peanut

    Authors and Affiliations
    • Albert K. Culbreath1
    • Timothy B. Brenneman1
    • Robert C. Kemerait Jr.1
    • Emily G. Cantonwine2
    1. 1Department of Plant Pathology, The University of Georgia, Coastal Plain Experiment Station, Tifton, GA 31793
    2. 2Department of Biology, Valdosta State University, Valdosta, GA 31698

    Published Online:

    Management of fungicide resistance in Nothopassalora personata, the cause of late leaf spot of peanut (Arachis hypogaea), is a challenge in peanut production areas of the southeastern United States. Field experiments were conducted in Tifton, Georgia, in 2020 and 2021 and in Plains, Georgia, in 2021 to determine the effects of mixtures of seven elemental sulfur fungicide products with the quinone outside inhibitor (QoI) fungicide azoxystrobin on late leaf spot in fields where QoI-resistant populations of N. personata are suspected. Application of azoxystrobin or sulfur alone resulted in little reduction of the standardized area under the disease progress curve (SAUDPC) or final disease intensity ratings compared with the nontreated control. However, mixtures of azoxystrobin with all micronized sulfur products evaluated had SAUDPC values and final disease intensity ratings less than those in the azoxystrobin-alone or Microthiol Disperss 80W sulfur-alone treatments. One nonmicronized sulfur formulation had SAUDPC values and final intensity ratings similar to those of azoxystrobin or Microthiol Disperss 80W sulfur alone. The results suggest that multiple micronized elemental sulfur products have potential for use as mixing partners with azoxystrobin leaf spot control in fields where the efficacy of azoxystrobin alone is not adequate.

    Literature Cited

    • Branch, W. D. 2017. Registration of ‘Georgia-16HO’ peanut. J. Plant Reg. 11:231-234. Crossref, ISIGoogle Scholar
    • Brunner, E., Domhof, S., and Langer, F. 2002. Nonparametric Analysis of Longitudinal Data in Factorial Experiments. John Wiley and Sons, New York, NY. Google Scholar
    • Cantonwine, E. G., Culbreath, A. K., Shew, B. B., and Boudreau, M. A. 2008. Efficacy of organically acceptable fungicides for management of early and late leaf spot diseases on partially resistant peanut cultivars. Plant Health Prog. 9. LinkGoogle Scholar
    • Chiteka, Z. A., Gorbet, D. W., Knauft, D. A., Shokes, F. M., and Kucharek, T. A. 1988. Components of resistance to late leafspot in peanut. II. Correlations among components and their significance in breeding for resistance. Peanut Sci. 15:76-81. CrossrefGoogle Scholar
    • Culbreath, A. K., Brenneman, T. B., Kemerait, R. C., Stevenson, K. L., and Anco, D. J. 2019. Combinations of elemental sulfur with demethylation inhibitor fungicides for management of late leaf spot (Nothopassalora personata) of peanut. Crop Prot. 125:104911. ISIGoogle Scholar
    • Culbreath, A. K., Brenneman, T. B., Kemerait, R. C., and Stevenson, K. L. 2016. Changes in the efficacy of pyraclostrobin for control of peanut leaf spot diseases. Proc Am. Peanut Res. Educ. Soc. 48:67 (abstr.). Google Scholar
    • Culbreath, A. K., Brenneman, T. B., Kemerait, R. C., Stevenson, K. L., and Henn, A. 2020. Effect of DMI and QoI fungicides mixed with the SDHI fungicide penthiopyrad on late leaf spot of peanut. Crop Prot. 137:105298. Crossref, ISIGoogle Scholar
    • Culbreath, A. K., Gevens, A. J., and Stevenson, K. L. 2018. Relative effects of demethylation-inhibiting fungicides on late leaf spot of peanut. Plant Health Prog. 19:23-26. Link, ISIGoogle Scholar
    • Kemerait, R., Culbreath, A., Prostko, E., Brenneman, T., Tubbs, S., Srinivasan, R., Abney, M., Monfort, S., Rabinowitz, A., Tillman, B., Dufault, N., Mulvaney, M., Small, I. M., Hagan, A., Chen, C., Jacobson, A., Balkum, K., Strayer-Scherer, A., Zerweller, B., and Anco, D. 2020. Peanut Rx: Minimizing diseases of peanut in the southeastern United States: The 2020 version of the peanut disease risk index. Pages 36-55 in: 2020 Peanut Production Update. W. S. Monfort, ed. University of Georgia Cooperative Extension Publication CSS-12-0130, Athens, GA. Google Scholar
    • Little, E. L. 2020. 2018 Georgia Plant Disease Loss Estimates. University of Georgia Cooperative Extension Annual Publication, Athens, GA. Google Scholar
    • Madden, L. V., Hughes, G., and van den Bosch, F. 2007. The Study of Plant Disease Epidemics. American Phytopathological Society, St. Paul, MN. Google Scholar
    • Monfort, W. S., Culbreath, A. K., Stevenson, K. L., Brenneman, T. B., Gorbet, D. W., and Phatak, S. C. 2004. Effects of reduced tillage, resistant cultivars, and reduced fungicide inputs on progress of early leaf spot of peanut (Arachis hypogaea). Plant Dis. 88:858-864. Link, ISIGoogle Scholar
    • Nutter, F. W., Jr., and Shokes, F. M. 1995. Management of foliar diseases caused by fungi. Pages 65-73 in: Peanut Health Management. H. A. Melouk and F. M. Shokes, eds. American Phytopathological Society, St. Paul, MN. Google Scholar
    • Schappe, T., Shew, B. B., and Thiessen, L. D. 2020. Surveying quinone outside inhibitor (QoI) resistance in peanut late leaf spot (Nothopassalora personata) in eastern North Carolina in 2018. (Abstr.). Phytopathology 110:S1.14. ISIGoogle Scholar
    • Schnabel, G., Layne, D. R., and Holb, I. J. 2007. Micronised and non-micronised sulphur applications control peach scab equally well with negligible differences in fruit quality. Ann. Appl. Biol. 150:131-139. Crossref, ISIGoogle Scholar
    • Shah, D. A., and Madden, L. V. 2004. Nonparametric analysis of ordinal data in designed factorial experiments. Phytopathology 94:33-43. Link, ISIGoogle Scholar
    • Shaner, G., and Finney, R. E. 1977. The effect of nitrogen fertilization on the expression of slow-mildewing resistance in Knox wheat. Phytopathology 77:1051-1056. Crossref, ISIGoogle Scholar
    • Shokes, F. M., and Culbreath, A. K. 1997. Early and late leaf spots. Pages 17-20 in: Compendium of Peanut Diseases, 2nd ed. N. Kokalis-Burelle, D. M. Porter, R. Rodriguez-Kabana, and P. Subrahmanyam, eds. American Phytopathological Society, St. Paul, MN. Google Scholar
    • Stevenson, K. L., and Culbreath, A. K. 2019. Fungicide resistance in peanut pathogens in the United States. Pages 333-338 in: Fungicide Resistance in North America, 2nd edition. K. L. Stevenson, M. T. McGrath, and C. A. Wyenandt, eds. American Phytopathological Society, St. Paul, MN. Google Scholar
    • Stevenson, K. L., Padgett, G. B., and Culbreath, A. K. 1999. Sensitivity of early and late peanut leaf spot pathogens to DMI fungicides. Proc. Am. Peanut Res. Ed. Soc. 31:23 (abstr.). Google Scholar