Abstract
This study aimed to determine if potassium silicate (KSi) sprays could reduce the intensity of soybean rust. In the field experiment 1, soybean plants were sprayed with KSi (pH 10.5) at rates of 8, 20, 40 and 60 g/L. In the field experiment 2, with the same treatments, the pH of the KSi solutions was 5.5. In experiment 3, the treatments were KSi (40 g/L, pH 10.5), potassium hydroxide (KOH) (6.5 g/L,pH10.5), epoxiconazole + pyraclostrobin, and control. In experiment 4, the treatments were the same as in experiment 3, but the pH of the KSi and KOH solutions was adjusted to 5.5. Plants sprayed with water served as a control treatment for all field experiments. Plants were artificially inoculated with Phakopsora pachyrhizi before the application of products. Even though there was no relationship between silicon (Si) concentration in leaf tissue and KSi rates, Si concentration increased by 67% and 73% respectively above the control, when averaged across all KSi rates for experiments 1 and 2. The relationship between the severity of soybean rust and KSi rates atpH10.5 and 5.5 was, respectively, linear and quadratic. Soybean rust severity at the highest KSi rate (pH 5.5) was70%less than the control. In experiments 3 and 4, the highest disease severity was observed on the control treatment which differed from other treatments. The application of KSi at pH of 10.5 (Exp. 3) and 5.5 (Exp. 4) decreased soybean rust severity by 36% and 43%, respectively, over the control. No significant difference in disease severity was found between KSi and KOH treatments, but they were significantly different, regardless of pH used, from the epoxiconazole + pyraclostrobin treatment. In greenhouse experiments, Si concentration in leaf tissue was higher with the application of KSi, regardless of the pH of the solutions, as compared with water spray. Soybean rust severity and the number of pustules were higher on leaves of plants sprayed with water, as well as on those sprayed with phosphoric acid + NaOH, and phosphoric acid + KOH, when compared with the application of KSi. There was no difference between the KSi and KOH treatments, regardless of the pH, and epoxiconazole + pyraclostrobin sprays for disease severity and number of pustules. This is the first study where field and greenhouse experiments have demonstrated a reduction of soybean rust intensity with foliar application of KSi. This information may be valuable in areas where soybean is grown as a monoculture, and where high yielding but susceptible cultivars cannot be grown because of the occurrence of frequent severe epidemics.
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References
Bélanger RR, Bowen PA, Ehret DL, Menzies JG (1995) Soluble silicon: its role in crop and disease management of greenhouse crops. Plant Disease 79, 329–336.
Bowen P, Menzies J, Ehret D (1992) Soluble silicon sprays inhibit powdery mildew development on grape leaves. Journal of the American Society for Horticultural Science 117, 906–912.
Bromfield KR (1980) Soybean rust: some considerations relevant to threat analysis. Protection Ecology 2, 251–257.
Costamilan LM, Godoy CV, Soares RM, Yorinori JT, Almeida AMR (2008) Studies on rust in south Brazil. JIRCAS Working Report 58, 39–40.
Datnoff LE, Rodrigues FA, Seebold KW (2007) Silicon and Plant Disease In ‘Mineral Nutrition and Plant Disease’. (Eds LE Datnoff, WH Elmer, DM Huber) pp. 233–246. (The American Phytopathological Society Press: St Paul)
Fehr WR(1977) Stages of soybean development. Special Report, Agriculture and Home Economics Experiment Station, Iowa State University of Science and Technology, 11 pp.
Godoy CV, Koga LJ, Canteri MG (2006) Diagrammatic scale for assessment of soybean rust severity. Fitopatologia Brasileira 31, 63–68. doi: 10.1590/S0100-41582006000100011
Gomez KA, Gomez AA (1994) Statistical Procedures for Agricultural Research. 2nd edn. (JohnWiley & Sons: New York)
Guével MH, Menzies JG, Bélanger RR (2007) Effect of root and foliar applications of soluble silicon on powdery mildew control and growth of wheat plants. European Journal of Plant Pathology 119, 429–436. doi: 10.1007/s10658-007-9181-1
Koch E, Hoppe HH (1988) Development of infection structures by the direct-penetrating soybean rust fungus (Phakopsora pachyrhizi Syd.) on artificial membranes. Journal of Phytopathology 122, 232–244. doi: 10.1111/j.1439-0434.1988.tb01012.x
Korndörfer GH, Pereira HS, Nolla A (2004) Análise de silício: solo, planta e fertilizante. Boletin Técnico 1, vol. 1. Grupo de Pesquisa em Silício, ICIAG-Universidade Federal de Uberlândia, 28 pp.
Liang YC, Sun WC, Si J (2005) Effects of foliar- and root-applied silicon on the enhancement of induced resistance to powdery mildew in Cucumis sativus. Plant Pathology 54, 678–685. doi: 10.1111/j.1365-3059.2005.01246.x
Ma JF, Miyaki Y, Takahashi E (2001) Silicon as a beneficial element for crop plants. In ‘Silicon in Agriculture’. (Eds LE Datnoff, GH Snyder, GH Korndörfer) pp. 17–39. (Elsevier Science Publishing: New York, NY, USA)
Melching JS, Dowler WM, Koogle DL, Royer MH (1989) Effects of duration, frequency, and temperature of leaf wetness periods on soybean rust. Plant Disease 73, 117–122. doi: 10.1094/PD-73-0117
Menzies J, Bowen P, Ehret DL, Glass ADM (1992) Foliar applications of potassium silicate reduce severity of powdery mildew on cucumber, muskmelon, and zucchini squash. Journal of the American Society for Horticultural Science 117, 902–905.
Miles MR, Hartman GL, Levy C, Morel W (2003) Current status of soybean rust control by fungicides. Pesticide Outlook 14, 197–200. doi: 10.1039/ b311463p
Mitani N, Ma JF (2005) Uptake system of silicon in different plant species. Journal of Experimental Botany 56, 1255–1261. doi: 10.1093/jxb/eri121
Miyaki Y, Takahashi E (1985) Effect of silicon on the growth of soybean plants in a solution culture. Soil Science and Plant Nutrition 31, 625–636.
Nolla A, Korndörfer GH, Coelho L (2006) Efficiency of calcium silicate and carbonate in soybean disease control. Journal of Plant Nutrition 29, 2049–2061. doi: 10.1080/01904160600932658
Novais RF, Neves JCL, Barros NF (1991) Ensaio em ambiente controlado. In ‘Métodos de pesquisa em fertilidade do solo”. (Eds AL Oliveira, WE Garrido, JD Araújo, S Lourenço) pp. 153–189. (Brasilia, DF: EMBRAPA-SEA)
Reis EF, Lima Neto VC, Godoy CV, Rosa CT, Castanho HE, Vicente NG (2007) Controle quimico da ferrugem asiática da soja na região sul do Paraná. Scientia Agrária 8, 319–323.
Rodrigues FA, Datnoff LE, Korndörfer GH, Seebold KW, Rush MC (2001) Effect of silicon and host resistance on sheath blight development in rice. Plant Disease 85, 827–832. doi: 10.1094/PDIS.2001.85.8.827
Rodrigues FA, Vale FXR, Datnoff LE, Prabhu AS, Korndörfer GH (2003) Effect of rice growth stages and silicon on sheath blight development. Phytopathology 93, 256–261. doi: 10.1094/PHYTO.2003.93.3.256
Seebold KW, Kucharek TA, Datnoff LE, Correa-Victoria JF, Marchetti MA (2001) The influence of silicon on components of resistance to blast in susceptible, partially resistant, and resistant cultivars of rice. Phytopathology 91, 63–69. doi: 10.1094/PHYTO.2001.91.1.63
Sinclair JB, Hartman GL (1999) Soybean diseases. In ‘Compendium of soybean diseases’. (Eds GL Hartman, JB Sinclair, JC Rupe) pp. 3–4. (The American Phytopathological Society Press: St Paul)
Takahashi E, Ma JF, Miyake Y (1990) The possibility of silicon as an essential element for higher plants. Comments Agricultural and Food Chemistry 2, 357–360.
Yang XB, Tschanz AT, Dowler WM, Wang TC (1991) Development of yield loss models in relation to reductions of components of soybean infected with Phakopsora pachyrhizi. Phytopathology 81, 1420–1426. doi: 10.1094/Phyto-81-1420
Yorinori JT, Paiva WM, Frederick RD, Costamilan LM, Bertagnolli PF, Hartman G, Godoy CV, Nunes Júnior J (2005) Epidemics of soybean rust (Phakopsora pachyrhizi) in Brazil and Paraguay from 2001 to 2003. Plant Disease 89, 675–677. doi: 10.1094/PD-89-0675
Yoshida S, Ohnishi Y, Kitagishi K (1962) Chemical forms, mobility and deposition of silicon in rice plant. Soil Science and Plant Nutrition 8, 15–21.
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Rodrigues, F.A., Duarte, H.S.S., Domiciano, G.P. et al. Foliar application of potassium silicate reduces the intensity of soybean rust. Australasian Plant Pathology 38, 366–372 (2009). https://doi.org/10.1071/AP09010
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DOI: https://doi.org/10.1071/AP09010
