Silicon, acibenzolar-S-methyl and potassium phosphite in the control of brown spot in rice

Kelly Juliane Telles Nascimento,Washington Luís Da Silva,Fabrício De Ávila Rodrigues,Renata Sousa Resende,Daniel Augusto Schurt,Leonardo Araujo

doi:10.1590/1678-4499.281

Kelly Juliane Telles Nascimento, Washington Luís Da Silva + Show 4 more

Open Access

https://doi.org/10.1590/1678-4499.281

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Journal: Bragantia	Publication Date: Feb 26, 2016
Citations: 24	License type: cc-by

Affiliation: Universidade Federal de Viçosa

Abstract

This study investigated the effects of silicon (Si), acibenzolar-S-methyl (ASM), and potassium phosphite (Phi) on the potentiation of rice resistance to infection by Bipolaris oryzae. The treatments included the soil amended with Si (1.25 g of calcium silicate per kg of soil), spraying of plants with ASM (500 mg∙L–1), Phi (5 mL∙L–1), and distilled water (control) 24 h before inoculation with B. oryzae. The treatments Si supply and the spraying of ASM and Phi were effective in reducing the area under brown spot progress curve and the number of lesions per cm2 of leaf. Polyphenoloxidases activity was higher for plants supplied with Si. On plants sprayed with ASM, the activities of polyphenoloxidases, phenylalanine ammonia-lyases, chitinases, and β-1,3-glucanases increased. The spraying of plants with Phi did not increase the activities of the studied defense enzymes. Taken together, the results of this study indicated that brown spot symptoms can be greatly reduced with the use of Si, ASM, and Phi.

Highlights

Rice (Oryza sativa L.) is the second most widely grown cereal crop and the staple food for more than half the world’s population (Van Nguyen and Ferrero 2006)
Strategies for brown spot control are limited because commercial cultivars with a high level of resistance are not available to the growers, the control of the disease is mainly dependent on fungicides application (Ou 1985)
Wollastonite was used as the Si source [calcium silicate (CS; CaSiO3); Vansil, EW-10, Ipiranga Chemical Co., São Paulo, Brazil], and it is composed of 24.2% Si and 31% Ca

Summary

Introduction

Rice (Oryza sativa L.) is the second most widely grown cereal crop and the staple food for more than half the world’s population (Van Nguyen and Ferrero 2006). Strategies for brown spot control are limited because commercial cultivars with a high level of resistance are not available to the growers, the control of the disease is mainly dependent on fungicides application (Ou 1985) In this way, finding alternative methods for brown spot management is necessary to avoid the yield losses caused by this disease (Dallagnol et al 2011; 2013; Rezende et al 2009). In light of these concerns, the supply of silicon (Si) and the use of inducers of resistance to crops of economical importance, such as rice, are shown as an environmentally friendly choice considering the potential of these products to decrease the intensities of important diseases (Araujo et al 2008, 2015, 2016; Rios et al 2014; Rodrigues et al 2003, 2004, 2005)

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