Soluble Silicon Sprays Inhibit Powdery Mildew Development on Grape Leaves

Abstract

<jats:p>The effect of root or leaf applications of soluble Si on severity of grape <jats:italic>(Vitis vinifera</jats:italic> L.) powdery mildew <jats:italic>[Uncinula necator</jats:italic> (Schwein) Burrill] was determined. On potted plants, root-feeding at 1.7 m<jats:sc>m</jats:sc> Si had no effect on disease severity, but foliar sprays at 17 m<jats:sc>m</jats:sc> Si substantially reduced the number of mildew colonies that developed on inoculated leaves. Scanning electron micrographs showed that, on Si-sprayed leaves, hyphae did not develop in areas where thick Si deposits were present on the leaf surface; and where surface deposits were not present, Si was translocated laterally through the leaf and surrounded the appressoria. Leaves on plants that were fed Si via roots showed a similar deposition of Si surrounding the appressoria. On water-sprayed leaves and leaves from untreated plants, internal deposition of Si was more variable and generally less than on Si-sprayed or root-fed plants. Conidia germination and germtube development on agar media were weakly promoted by the presence of Si. Reduced severity of grape mildew by Si sprays may be partly due to a physical barrier to hyphal penetration and to a resistance response involving the lateral movement of Si and its deposition within the leaf at fungal penetration sites.</jats:p>

Induction and mechanism of cucumber resistance to anthracnose induced by Pieris rapae extract

“…Although the nature of the P. rapae extract has not been identified, the inherent compound possessed basic characteristics as an elicitor that reduces cucumber damage from C. orbiculare. It agrees with previous reports that foliar-applied Si significantly suppressed downy mildew (Bowen et al, 1992). The P. rapae extract could inhibit the conidium germination of C. orbicular but not the mycelium growth in vitro at the concentration used in this study.…”

Silicon enhances photochemical efficiency and adjusts mineral nutrient absorption in Magnaporthe oryzae infected rice plants

“…There are numerous reports on Si suppressing plant diseases and pests, such as blast and sheath blight in rice (Datnoff et al 1997;Seebold et al 2001;Rodrigues et al 2003;Cai et al 2008), powdery mildew in cucumber, Arabidopsis in wheat Fauteux et al 2006;Côté-Beaulieu et al 2009), Eldana saccharina in sugarcane (Keeping and Meyer 2002), and rust in cowpea (Heath and Stumpf 1986). Evidence showed that siliconmediated resistance to the pathogen is associated with the higher deposit of silicon in leaf and the activation of host defense response (Bowen et al 1992;Kim et al 2002;Rémus-Borel et al 2005;Cai et al 2008).…”

The Effect of Calcium and Silicon Foliar Fertilization in Sugar Beet

“…Its major role is to increase the plant resistance to pathogens, pests and diseases, especially to fungal diseases, thereby contributing to plant health and yield improvement (Bowen et al 1992;Raven 2003;Henriet et al 2006). One of the most important beneficial effects of silicon on plant growth is related to increased resistance under water stress conditions (Ma et al 2004;Sacała 2009).…”