Role of Silicon on Enhancing Disease Resistance in Tropical Fruits and Vegetables: A Review

Abstract

Silicon (Si) has proven to enhance disease resistance in a wide range of tropical fruits and vegetables. It has been used in controlling various diseases: mildews, rots, moulds, wilt, blight, anthracnose and leaf spots. However, the highest number of records was available on reducing diseases of powdery mildews on fruits and vegetables belonging to the family Cucurbitaceae. Siliconmediated defense responses in plant pathosystems are mainly attributed to the physical resistance, which involves reduced penetrability and/or increased hardness and abrasiveness of plant tissues because of silica deposition. The main mechanism is the chemical resistance, which involves chemical defenses to pathogen attack through the enhanced production of defensive enzymes and the production of antifungal compounds such as phenolic metabolism products, phytoalexins and pathogenesis related proteins. Silicon has been applied as soluble silicates to the substrate or to soilless media at pre-harvest level on reducing disease susceptibility. Post-harvest dips of fresh produce in silicate solutions and use of Si combined with a biocontrol agent are other aspects of silicon application in controlling diseases in fruits and vegetables.

Potassium silicate treatment enhances natural disease resistance in <i>Capsicum annuum</i> L. and reduces anthracnose disease development

“…It also satisfies the requirements, such as, no toxicity to pathogens, plants or animals, not affecting plant growth, development and yield, broad spectrum of defense and long lasting (Kessman et al, 1994;Tally et al, 1999;Kuc, 2001). There were several studies in the past proved that the enhanced natural disease resistance could be achieved with silicon (Si) treatment, in a wide range of tropical and sub-tropical fruits and vegetables (Weerahewa and Somapala, 2016;Huang et al, 2011;French-Monar et al, 2010). This has been achieved through different role of silicon, include; reduced mineral toxicity, increased photosynthetic activity, superior nutrient imbalance, and enhanced drought and frost tolerance (Ma, 2004).…”

Exploring the efficacy of silicon supplementation on control of rice grain discoloration disease

“…Most of the studies showed that seed treatment with synthetic fungicides and foliar application of synthetic fungicide are most effective to control rice grain discoloration disease (Agarwal et al, 1989;Arshad et al, 2009). However, continuous use of fungicides can lead to health and environmental problems (Korndorfer et al, 1999) and development of fungicide resistance of pathogen populations (Jayawardana and Weerahewa, 2016). Therefore, to address the current demand in sustainable crop production and concern of food safety, environmental friendly alternatives should be investigated to control rice grain discoloration disease.…”

“…Si is beneficial for plants in terms of yield (Ghasemi et al, 2013), growth and resistance to biotic and abiotic stresses (Datnoff et al, 1992). Addition of Si can decrease the incidence of several diseases in rice such as blast, brown spot, sheath blight, grain discoloration and disease bacterial leaf blight (Jayawardana and Weerahewa, 2016).…”

“…It acts as a physical barrier, deposited beneath the cuticle, to impede penetration by fungal appressoria, thereby disrupting the process of infection (Jayawardana et al, 2015). Si may signal a biochemical mechanism to suppress fungal infection and disease (Weerahewa and Somapala, 2016). Si could induce defense responses such as systemic acquired resistance (Jayawardana and Weerahewa, 2016).…”

“…Si may signal a biochemical mechanism to suppress fungal infection and disease (Weerahewa and Somapala, 2016). Si could induce defense responses such as systemic acquired resistance (Jayawardana and Weerahewa, 2016). Hence, inorganic form of Si would be used as solution form to spray on the plant.…”