Soil-applied silicon decreases severity of wheat spot blotch on silicon-deficient soils

Abstract

SUMMARYSpot bloth caused by Bipolaris sorokiniana is an important wheat desease mainly in hot and humid regions. The aim of this study was to evaluate the response of wheat to different sources and modes of Si application, as related to the severity of wheat spot blotch and plant growth, in two Si-deficient Latosols (Oxisols). An greenhouse experiment was arranged in a 2 x 5 factorial completely randomized design, with eight replications. The treatments consisted of two soils (Yellow Latosol and Red Latosol) and five Si supply modes (no Si application; Si applied as calcium silicate and monosilicic acid to the soil; and Si applied as potassium silicate or monosilicic acid to wheat leaves). No significant differences were observed between the two soils. When Si was applied to the soil, regardless the Si source, the disease incubation period, the shoot dry matter yield and the Si content in leaves were greater. Additionally, the final spot blotch severity was lower and the area under the spot blotch disease progress curve and the leaf insertion angle in the plant were smaller. Results of Si foliar application were similar to those observed in the control plants.Index terms: Triticum aestivum L., Bipolaris sorokiniana (Sacc. in Sorok.), plant nutrition, Si.(

O alto teor de silício no solo inibe o crescimento radicular de cafeeiros sem afetar as trocas gasosas foliares

“…A maior parte dos estudos que comprovam os benefícios do Si na agricultura foi realizada com espécies herbáceas de rápido crescimento (Goto et al, 2003;RomeroAranda et al, 2006;Hattori et al, 2007;Côté-Beaulieu et al, 2009;Savvas et al, 2009;Hashemi et al, 2010;Zanão Júnior et al, 2010). O hábito de crescimentolento em espécies arbóreas, como o cafeeiro, ou rápido em espécies herbáceas, como o arroz -parece ser um fator adicional que altera a resposta ao Si, sendo o benefício mais evidente nas espécies anuais.…”

“…O Si é um elemento que confere às plantas maior resistência a estresses bióticos e abióticos (Goto et al, 2003;Romero-Aranda et al, 2006;Hattori et al, 2007;Côté-Beaulieu et al, 2009;Savvas et al, 2009;Hashemi et al, 2010), assim como melhora o manejo fitossanitário de cafeeiros (Reis et al, 2008) e plantas de trigo (Zanão Júnior et al, 2010).…”