The use of chitosan as a biological control remedy

Abstract

A review. Losses in agricultural products occur due to soil and leaf pathogens, such as viruses, fungi and insects, before and after harvest. Damage to the agricultural products also causes economic losses in the domestic and international trade. Chem. insecticides and fungicides are used to limit the losses, but their use can pose a risk to human health and disrupt biol. balance in the environment. The emergence of pesticide-tolerant pathogenic organisms has revealed the inadequacy of such chem. protection products. Ecol. natural products, which do not harm human health, can be an alternative to chem. control means. The use of natural products to control pathogenic fungi and bacteria and to prolong storage shelf-life of fruit and vegetables is getting more attention. Examples of the natural products are acetic acid, jasmonate, propolis, chitosan, essential oils, and plant exts. Chitin, a polymer based on N-acetyl-D-glucosamine monomer residues linked by β-1,4 bonds, is the most abundant renewable natural resource after cellulose. Chitin is the main component of cell walls of fungi and exoskeletons of arthropods, crustaceans, crabs, lobsters, shrimps, mollusk radula, cephalopods, and octopuses. Chitin can be obtained from these sources by chem. methods. Chitosan, produced by partial deacetylation of chitin, is a natural product with antimicrobial, antifungal, and insecticidal activities and can be used in the biol. control. Chitosan can inhibit the growth of soil and foliar plant pathogens, increase plant disease resistance, and extend the shelf-life of horticultural commodities. Chitosan and its derivs. are of interest also for their biomedical properties, in food processing, agriculture, and waste water treatment. [on SciFinder(R)]