Sharp R G. Agronomy, 2013, 3(4), 757-793.
There are lots of research evidence that chitin and its derivatives can increase crop yields. Aside from direct nutrition and growth stimulation in plants, chitin derivatives are also toxic to plant pests and pathogens, increase plant defences, and increase the activity of beneficial microbes. We include some related research examples here:
· Direct antimicrobial action: Chitosan has been repeatedly found to have potent antimicrobial activity, which is attributed to its cationic properties and disruption of potassium signaling in pathogens. The fungus diseases in many crops, including fusarium wilt and gray mould, have been effectively controlled by soil amendments such as chitosan, for instance. Yet polymeric chitin is not significantly antimicrobial, and it's because chitin is insoluble and uncharged that it isn't antimicrobial.
· Enhance probiotic microorganisms: Adding chitin to the environment changes the rhizosphere and phyllosphere conditions so that microbial balance favors probiotics and plants pathogens. For instance, in addition to their bactericidal activity against Bacillus subtilis, chitin and chitosan reduce tomato and cucumber fusarium wilt diseases when used on soil containing different species of chitin-degrading microorganisms.
· Induces plant defense responses: Chitin, especially chitosan, is a potent inducer of plant defense, thereby enabling plants to resist or tolerate a variety of diseases. A series of "chitin elicitor binding proteins" (CEBiPs) have been isolated from a variety of crops. CEBiP receptors respond to chitin oligomers released by pests and pathogens when they are degraded by chitinases produced by the plant in the apoplast and symplast.
