Chitin nanofibers and chitosan nanoparticles are used as means of combating plant diseases. For example, chitin nanofibers prepared from high molecular weight polymer, dispersed in water were used for treatment of Brassicaceae family sprouts (Arabidopsis seedlings) (Article Chitin Nanofiber Elucidates the Elicitor Activity of Polymer...
). Chitin triggered production of reactive oxygen species important for signaling role in growth and development and induced defense-related gene expression in Arabidopsis seedlings. Furthermore, pre-treatment of Arabidopsis leaves with chitin nanofibers effectively reduced pathogen infection by both the fungus Alternaria brassicicola and the bacterium Pseudomonas syringae pv. tomato DC3000.
Pragathi G et al. showed that (in the attached file) a coating based on polyvinyl alcohol and chitosan nanofibers with immobilized growth-promoting microbial cells increased the germination and viability of cotton seeds.