Prospective applications of chitosan and chitosan-based nanoparticles formulations in sustainable agricultural practices

Chemical pesticides, fungicides, fertilizers, and high-breeding crop varieties are normally used to enhance crop productivity worldwide. Nevertheless, overuse and persistence of these chemicals has negative effects on soil, water, and air, disrupting the food chain and the ecosystem. Recent advances in nanotechnology, particularly for the agriculture sector are being explored in crop production and protection with particular focus on nano-pesticides, nano-fertilizers, nanobiosensors, nano-devices as remediation strategies to deal with toxic effects of chemicals. The efficiency and fate of nanomaterials are heavily influenced by their properties and interactions with soil constituents. Chitosan (CH) and chitosan nanoparticles (CHNPs) are the remarkable due to their exceptional structural and functional properties including antimicrobial potential against several phytopathogens (feed, food, cereals, fibre, oil, industrial, medicinal, ornamental crops). CH and CHNPs can be applied individually and/or in combinations with other active components to manage plant diseases. This review highlights the role of CH and CHNPs in the defence mechanisms in plants and other promising agricultural applications. It also presents information on fungal chitosan (FCH) along with its promising functional properties over the CH of crustacean origin and strategies employed for the preparation of NPs-based (CHNPS or FCHNPs) formulations. Biosynthesis of CHNPs or FCHNPs using CH or FCH is also described briefly. Information on the patents granted for CH and CHNPs in the agriculture sector is included. The role of other additives like surface active or wetting agents, dispersants, UV protectants in designing the powerful agro-nanoformulations for future development of a sustainable nano-enabled agriculture practices are described.