Sustainable Agriculture Systems in Vegetable Production Using Chitin and Chitosan as Plant Biostimulants.

Mohamad Hesam Shahrajabian,Nikolaos Tzortzakis,Nikolaos Polyzos,Spyridon A Petropoulos,Christina Chaski

doi:10.3390/biom11060819

Mohamad Hesam Shahrajabian, Nikolaos Tzortzakis + Show 3 more

Open Access

https://doi.org/10.3390/biom11060819

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Abstract

Chitin and chitosan are natural compounds that are biodegradable and nontoxic and have gained noticeable attention due to their effective contribution to increased yield and agro-environmental sustainability. Several effects have been reported for chitosan application in plants. Particularly, it can be used in plant defense systems against biological and environmental stress conditions and as a plant growth promoter—it can increase stomatal conductance and reduce transpiration or be applied as a coating material in seeds. Moreover, it can be effective in promoting chitinolytic microorganisms and prolonging storage life through post-harvest treatments, or benefit nutrient delivery to plants since it may prevent leaching and improve slow release of nutrients in fertilizers. Finally, it can remediate polluted soils through the removal of cationic and anionic heavy metals and the improvement of soil properties. On the other hand, chitin also has many beneficial effects such as plant growth promotion, improved plant nutrition and ability to modulate and improve plants’ resistance to abiotic and biotic stressors. The present review presents a literature overview regarding the effects of chitin, chitosan and derivatives on horticultural crops, highlighting their important role in modern sustainable crop production; the main limitations as well as the future prospects of applications of this particular biostimulant category are also presented.

Highlights

Modern agriculture needs to be adapted to the ongoing climate change and the growing food demands due to increasing population
Chitosan lactate foliar application may promote the accumulation of bioactive substances; increase the activity of antioxidant enzymes; improve photosynthetic rate and plant growth
Oligochitosan, with 3 to 10 saccharide residues of Nacetylglucosamine or glucosamine, include homo or hetero oligomers obtained from chitin by chemical or enzymatic hydrolysis [145], or though oxidative and ultrasonic degradation [146,147]

Summary

Introduction

Modern agriculture needs to be adapted to the ongoing climate change and the growing food demands due to increasing population. Modern crop production has to cope with biotic and abiotic stressors such as soil and irrigation water salinity, water limitations, extreme and untimely weather phenomena and infections from pathogens and pests, which severely affect crop performance and quality of the final products [29,30] In this context, the application of chitin, chitosan and derived biopolymers can play a pivotal role due to their confirmed biostimulatory activity in various crops, especially in vegetable species, which are more prone to stressors [31,32,33]. The chemical methods for production of chitin and their derivatives that are currently being applied on a commercial scale consist of two steps, namely, deproteinization by alkali treatment and demineralization by acidic treatment under high temperature, followed by the decolorization step which focuses on removing lipids and pigments [35]. Chitin goes through deacetylation by sodium hydroxide and produces chitosan [61,63]

Practical Applications of Chitosan on Vegetable Crops

Activities and Applications of Oligochitosan

The Use of Chitin as Biostimulant

Conclusions