Prospects of garlic extracts, selenium and silicon application for plant protection against herbivorous pests. Review

Protection of plants against herbivorous pests is an important aspect that guarantees agricultural efficiency, i.e., food provision to populations. Environmental, water and foodstuff pollution by toxic pesticides, along with climate changes, highlight the necessity to achieve intensive development of ecologically safe methods of herbivory control. This review discusses modern methods of plant protection against insect pests: the biofortification of plants with selenium, treatment of plants with bulk and nano-silicon, and utilization of garlic extracts. The peculiarities of such methods of defense are described in relation to growth stimulation as well as increasing the yield and nutritional value of products. Direct defense methods, i.e., mechanical, hormonal, through secondary metabolites and/or mineral element accumulation, and indirect defense via predator attraction are discussed. Examples of herbivorous pest control during plant growth and grain/seed storage are emphasized. A comparison of sodium selenate, silicon containing fertilizer (Siliplant) and garlic extract efficiency is analyzed on Raphanus sativus var. lobo infested with the cruciferous gall midge Contarinia nasturtii, indicating the quick annihilation of pests as a result of the foliar application of garlic extract or silicon-containing fertilizer, Siliplant.