ABSTRACT
This chapter presents progress on the bioactivity of chitin and its derivatives, such as soluble chitin oligomers, chitosan, and chitosan derivatives, like sulfonated and carboxymethylated chitosan, in plant protection and growth stimulation. Chitosan is produced by deacetylation of chitin. Water-soluble chitin oligomers, chitosan, chitosan sulfate, and carboxymethyl chitosan were used in this research. A special interest for the use of chitin and its derivatives is postharvest treatment subjected to harvest protection and harvest freshness protection. The usefulness of chitin and its derivatives in agricultural applications is in the following areas: biostimulation of plant growth; plant protection against fungi, bacterias, and viruses; and postharvest protection. Bioactivity, a most important property of polyaminosaccharides, is a function of several phenomena. A correlation between the structure of chitosan and its bioactivity resulting from the amount and type of oligoaminosaccharides produced during the biodegradation process of this natural polymer plays a most important position in the antimicrobial activity of chitosan.
