Effects of Nanosilica Powder from Rice Hull Ash on Seed Germination of Tomato (Lycopersicon esculentum)

Nanosilica powders were synthesized from rice hull ash (RHA) and their effects on seed germination of tomato plants were investigated. Synthesized nanosilica powder was subjected to various characterization studies for identification of the size, structure, morphology and elemental composition. Atomic force microscopy (AFM) and transmission electron microscopy (TEM) results showed that the nanoparticles were in agglomerated form with an average diameter of 46.5 nm and 40 nm, respectively. X-ray diffractometry (XRD) indicated that nanosilica powder is amorphous in nature. The nanosilica powder was also characterized as having a purity of 98.33% using EDXRF spectroscopy and having a surface area 172.19 m2 g-1 using the Brunauer-Emmett-Teller (BET) method. The study showed that nanosilica powder significantly improved germination parameters such as germination percentage, germination index, vigor index, mean germination time and average shoot length of tomato but not fresh weight and dry weight. The best results were found at 5gL-1 nanosilica powder. The increase over untreated control seeds was 22% for germination percentage, 47% for germination index, 92% for vigor index and 55% for average shoot length with the addition of 5 gL-1 nanosilica powder. Nanosilica powder-mediated improvement of seed germination in tomato suggests a potential application of nanosilica powder in seed germination of the plant. The study can serve as theoretical basis for further agricultural applications of nanosilica powder.