Nano-Particles: A Novel Approach in Crop Protection
Author: PATEL SANKETKUMAR VIKASHBHAI

Introduction:

"Nano" word is derived from the Greek word meaning “dwarf” In more technical terms, the word “nano” means 10^-9. The word nanotechnology evolved due to use of nanometre size particles (size of 1 to too nm). Nano-particles are completely different from their bulk materials and individual molecules because of their unique physical, chemical and biological properties (Li et al. 2001). These unique properties impart its novel applications in all the fields. In spite of it, they have large surface to volume ratio, chemically alterable physical properties, and possess strong affinity to targets such as proteins (Kumar et al. 2010).

Application of nano-particles in diseases and insect management :

Vegetables are spoiled by variety of bacterial and fungal pathogens. With the growing demand of pesticide worldwide to control the pathogens and pests, there is an urgent need to tackle the excessive usage of pesticides by finding alternatives. Chitosan, a deacetylated derivative of chitin, is found to be very effective in reducing postharvest decay of fruit and vegetables. Chitosan at a concentration of lg/L has found to be very effective in reducing the growth of several phytopathogenic fungi causing post-harvest spoilage of fruit and vegetables (Hirano, 1997). Kim et al. (2008), studied the antifungal effectiveness of colloidal nano silver (1.5 nm average diameter) solution, against rose powdery mildew caused by Sphaerotheca pannosa Var rosae. Complexation of copper with chitosan nanogels was shown to have strong synergistic effect between chitosan and copper in inhibiting the growth of phytopathogenic fungus Fusarium graminearum. Zinc nitrate derived nano-ZnO on important fungal pathogen Aspergillus Jumigatus showed hydroxyl and superoxide radicals mediated fungal cell wall deformity and death due to high energy transfer.

Nanoparticles are used to produce new pesticides, insecticides and insect repellants. Nanoencapsulation is a process which is used in pesticide industry, through which a chemical such as an insecticide is slowly but efficiently released to a particular host plant for insect pest control. Nanoencapsulation with nanoparticles in form of pesticides allows for proper absorption of-the chemical into the plants (Scrinis and Lyons, 2007). This process can also deliver DNA and other desired chemicals into plant tissues for protection of host plants against insect pests, nanoencapsulation include diffusion, dissolution, biodegradation and osmotic pressure with specific pH (Vidhyalakshmi et al, 2009). It has been reported that nanoparticles encapsulated with garlic essential oil are efficacious against Tribolium castaneum Herbst (Yang et al. 2009). Also, it is known that aluminosilicate filled nanotube can stick to plant surfaces while nano ingredients of nanotube have the ability to stick to the surface hair of insect pests and ultimately enters the body and influences certain. Physiological functions (Patil, 2009). Surface-modified hydrophobic as well as lipophilic nanosilica could be effectively used as novel drugs for treatment of nuclear polyhedrosis virus (BmNPV), a scourge in the silkworm industry. Also, research on silkworm, Bombyx mori L. race Nistari clearly demonstrates that nano particle could stimulate more production of fibroin protein which can help in producing carbon nano tube in. The above highlights the putative effects of nanoparticles on insects, as these small particles are present in their entire body parts. Research on nanoparticles and insect control should be geared toward introduction of faster and ecofriendly pesticides in future. It is high time therefore that leading chemical companies to focus on formulation of nano scale pesticides for delivery into the target host tissue through nanoencapsulation. At present, the toxicological and ecotoxicological risks linked to this expanding technology ("emerging technology") cannot be assessed yet. While nanotechnology is increasingly moving into the centre of public attention, it is currently not yet linked to any great degree to concerns about health and the environment.

References:
Li L. S., Hu J., Yang, W. and Alivisatos A. P. (2001). Band gap variation of size- and shape-controlled colloidal CdSe quantum rods. Nano Letters 1:349-351.

Kumar R., Sharon M. and Choudhary A. K. (2010). Nanotechnology in agricultural diseases and food safety. Journal of Phytology 2: 83.92.

Scrinis G. and Lyons K (2007). The emerging nano-corporateparadigm nanotechnology and the transformation of nature, food and agri-food systems. Int. J. Sociol. Food Agric. 15(2): 22-44.

Vidhyalakshmi R, Bhakyaraj R and Subhasree R. S. (2009). Encapsulation The Future of Probiotics-A Review. Adv. Biol. Res. 3(3-4):96-103.

YaneF L., Li X. G., Zhu F. and Lei C. L.(2009). Structural Characterization of Nanoparticles Lo-ided with Garlic Essential Oil and Their Insecticidal Activity against Tnbolium castancum (Herbst) (Coleop^era: Tenebrionidae). J. Agric. Food Chem.

57(21):10156-10162.

Patil SA (009). Economics of agn poverty: Nano-bio solutions. Indian Agricultural Research Institute, New Delhi, Indian.

Hirano S. (1997). Applications of chitin and Chitosan in the ecological and environment fields in: M.F.A. Goosen (Ed), Application of chitin and Chitosan, Technomic Publishing Company, pp: 31-54.

Kim H. S., Kang H. S., Chu G. J. and Byun H. S. (2008). Antifungal effectiveness of nanosilver colloid against rose powdery mildew in greenhouses. Solid State Phenomena, 135: 15-18.




About Author / Additional Info:
Ph. D. scholar (plant pathology)