Background:
Silicic acid is a bio-stimulant and is the only bioavailable form of silica which the plants absorb. Its uptake by the plant is important because silicon exerts many beneficial effects on plants like a) structural strength; b) an active role in many physiological processes; c) a role in growth and development especially when plants exposed to abiotic stresses and biotic stresses; and d) decreasing damage from insects and rodents due to the fortification of the plant, acting as a functional deterrent to herbivory. Consequently, its application significantly increases both crop productivity and quality:
However, silicic acid is a relatively unstable molecule with a tendency to polymerize slowly to soft gel which is poorly available to the plants. It remains in bioavailable form only when the concentration is very below approximately 10-4 mol Si. Up to the end of last millennium, silicic acid was not available in the market because of its instability. Since 2002, silicic acid, the only plant available silicon form, is being used due to patented production process in which polymerization of silicic acid is prevented. But in this patented process very high proportion (almost 50%) of stabilizer is used. The commercially available silicic acid formulation for foliar spray is composed of 0.8% Si, 1.2% potassium chloride, 0.2%B, 47.5% PEG-400 as stabilizer (HM Laane, Silicon, DOI 10.1007/s12633-016-9466-0). All the prior arts have used very high proportion of additives to stabilize the silicic acid formulation. The addition of stabilizer in such proportion (~50%) increases the cost of the product. The use of stabilizer in such high proportion not only increase the production cost of silicic acid formulation but also reduces the percent content of silicon in the formulation. It causes several other disadvantages also like increased shipping cost, large volume for storage. Therefore, there exists a need to develop a process for the preparation of silicic acid formulation without adding a stabilizer which will not only reduce the production cost of silicic acid formulation but also increase the concentration of silicon in per unit volume of the formulation. The present invention provides a production process which will solve the above said problems:
Technology Details:
Product of the present invention takes care of these problems. Accordingly, it is an object of the present invention to provide process for preparation of silicic acid formulation which is not subject to the disadvantages of preparations heretofore used. The principal objective of the present invention is to prepare non-colloidal silicic acid formulation suitable for foliar spray on crops. It is also an object of the invention to prepare silicic acid formulation without a stabilizer to reduce the cost of the product and increase the concentration of silicon in per unit volume of the formulation. It is a further object of the invention to provide separate two parts compositions which are stable for a considerable period of time. Other objects, features, and advantages will become apparent from the detailed description and appended claims to those skilled in the art. This invention comprises a two-part system and relates to a method for achieving low cost, stabilizer free non-colloidal silicic acid formulation through mixing of these two parts systems before application. Immediately, the resulting solution of non-colloidal silicic acid is further diluted for foliar application on crops. The two compositions are part A which is an aqueous acid composition having a pH in the range of 0.2 to 0.5; and part B, an aqueous alkali solution having a having a pH of from about 12 to 14 containing solubilised silica in the range from 1% to 20%, preferably 2% to 15%.