Silicon is the second most abundant element in the crust of the earth after oxygen, with a mean content of 28.8 % (weight). It is essential part of plant tissues analysis indicates that silicon makes up between 0.2% and 10% of a plant dry weight.
Silicon application enhance the resistance in plants against herbivorous insects and diseases. Silicon strengthen the cell wall of plant and prevent the many insects like that stem borer, Brown plant hopper, green leaf hopper and White back plant hopper.
Source of silicon:
Si is the second most abundant element in the earth’s crust, it is easy to find Si sources. But, Si is always combined with other elements and most sources are insoluble. The responses of the crops to the Si-soluble applications in the sands (largely SiO2) provide an example of the insolubility of a source. Slags, by products of the processing of the iron and alloy industries, have been used quite extensively. Its concentrations and solubility of Si and its content of other elements vary widely. For a given source, the solubility is indirectly related to the particle size.
Some sources are soluble, but too expensive for general use. Potassium silicate is used in agricultural agriculture to control diseases in some high-value crops. Sodium silicate and silica gel have also been used to supply Si in research and in high value crops.
Calcium silicates have become the most important sources for soil applications. Of these, calcium meta-silicate (wollasonite, CaSiO3) has been the most effective source in many places with low concentrations of soluble Si in soils. Said material, supplied as a slag byproduct of the production of elemental P high temperature electric furnaces, is extensively applied to the Everglades droppings and associated sands that are sown in sugarcane and rice.
Location and composition of Si in plants:
Site and arrangement of Si with in plant is very important in restricting the larval feeding and oviposition for egg laying. The density of the silica bodies present in the abaxial epidermis at the base of the first, second and third leaf sheaths (the area where the insect penetrates the plant) was higher than in a susceptible cultivar. Similarly, a study on rice revealed that the silica pattern in the epidermis of cultivars resistant to the leaf roller.
Action of Silicon:
The most widely accepted mechanisms for the action of Si in increasing the resistance of plants to attack by insects are a reduced digestibility and a greater hardness and abrasiveness of plant tissues (especially epidermal) due to the deposition of silica, mainly as opaline phytoliths and in association with cell walls. Silicon is not a much more mobile element in plants; therefore, a continuous supply of this element would be required, particularly for the healthy and productive development of the plant during all stages of growth.
In a field study, the height of the plant was quadratically related to the rate of application of Si, while it was linearly related to the stem diameter of the crop plant. In another solution, the experiment of cultivation with shoots of dry matter of cotton plants increased three times with the application of Si compared to the control.
Fungal hyphae and parasitic historian that successfully infect plant cells must break the cell wall, which they do through chemical means. The formation of a physical barrier in the epidermal cells by Si deposition contributes to the resistance of the plant against diseases and pests.
Pakistan’s climate is arid and semi-arid, and water stress in the fields is a common effect on crop yields. Silicon significantly improves the water economy of plants by reducing circular transpiration.
Silicon Supplementation doesn’t leave the residual in food and environment and its cheap easily available and integrated with other pest management practices like biological, chemical and cultural practices.
Collective efforts of Hafiz Muhammad waqas Amjad *1 Hamza khaliq 1 Shahroz khalid2