Abstract

Vegetable crops are increasingly exposed to new environmental conditions, including elevated temperatures, erratic rainfall patterns, and declining soil fertility, which threaten global food security. Traditional synthetic fertilizers and pesticides exacerbate environmental degradation. Chitosan, a biodegradable and non-toxic biopolymer derived from chitin, has been developed into nanomaterials such as nanoparticles and nanofibers. These chitosan-based nanomaterials, typically less than 100 nm in size, exhibit high biocompatibility and bioactivity, enhancing the chlorophyll content, nutrient uptake, and disease resistance in crops. Nonetheless, differences in synthetic processes and composition cause unstable efficacy, affording a 5–20% field-level increase in the yield, in comparison with 15–25% in controlled settings. This review explores current advances in chitosan nanomaterials for vegetable crop improvement under biotic and abiotic stress conditions, focusing on crops like tomatoes, potatoes, and lettuce. It critically evaluates benefits and limitations while emphasizing nanotechnology's role in achieving higher yields and environmental sustainability.