Chitosan as a Plant Growth Biostimulant: Enhancing Crop Yield and Quality

Vibrant crop growth in a sustainable farming landscape, exemplifying the promise of chitosan-based biostimulants for enhanced yield and resilience.

Introduction

In an era demanding sustainable agricultural practices and increased food security, the exploration of novel, environmentally friendly solutions for crop enhancement is paramount. Traditional agricultural methods often rely on synthetic chemicals, which, while effective, can pose significant environmental and health concerns. This necessitates a shift towards biostimulants that can naturally bolster plant growth, resilience, and productivity. Among these, chitosan, a natural biopolymer derived from chitin, has emerged as a highly promising candidate. Having examined chitosan's remarkable ability to remediate heavy metal contamination in agricultural soils in a previous article, we now turn to another of its agricultural applications: its multifaceted properties as a plant growth biostimulant offer a sustainable pathway to improving crop yield and quality, aligning perfectly with the global push for ecological agriculture. This article delves into the science behind chitosan's efficacy in this capacity, exploring its mechanisms of action, diverse applications, and the tangible benefits it offers in enhancing crop yield and quality.

The Multifaceted Role of Chitosan in Plant Physiology

Chitosan is a linear polysaccharide composed of randomly distributed β-(1→4)-linked D-glucosamine and N-acetyl-D-glucosamine, primarily obtained from the deacetylation of chitin, the second most abundant natural polymer after cellulose. Its unique chemical structure, particularly the presence of free amino and hydroxyl groups, underpins its remarkable biological activities and versatility in agricultural applications (Stasińska-Jakubas et al., 2022).

Healthy, vibrant tomatoes illustrate the impact of chitosan-mediated nutrient uptake, stress resilience, and enhanced crop quality.

Mechanisms of Action

Chitosan exerts its biostimulant effects through several key mechanisms:

1. Enhanced Nutrient Uptake and Mobilisation: Chitosan can improve the availability and absorption of essential nutrients by plants. It forms complexes with metal ions, making them more soluble and accessible in the soil. This chelating activity is particularly beneficial for micronutrients like iron, zinc, and copper, which are often limited in soil (Rojas-Pirela et al., 2024). Furthermore, chitosan can stimulate root development, increasing the root surface area for nutrient and water absorption (Román-Doval et al., 2023).

   
   

2. Modulation of Phytohormone Production: Chitosan influences the synthesis and balance of various plant hormones, including auxins, gibberellins, and cytokinins. For instance, it can promote the production of indole-acetic acid (IAA), a key auxin involved in cell elongation and root growth (Panichikkal et al., 2022). This hormonal modulation leads to improved plant growth, flowering, and fruit development (Abobatta, 2023).

   
   

3. Activation of Plant Defense Mechanisms: Chitosan acts as an elicitor, triggering systemic acquired resistance (SAR) in plants. It mimics pathogen-associated molecular patterns (PAMPs), activating defense genes and leading to the accumulation of phytoalexins, pathogenesis-related (PR) proteins, and antioxidant enzymes (Stasińska-Jakubas et al., 2022). This enhanced immunity provides protection against a wide range of biotic stresses, including fungal, bacterial, and viral infections (Abobatta, 2023).

   
   

4. Alleviation of Abiotic Stress: Chitosan helps plants cope with various abiotic stresses such as drought, salinity, extreme temperatures, and heavy metal toxicity. It achieves this by regulating osmotic adjustment, enhancing antioxidant enzyme activity (e.g., superoxide dismutase, catalase, peroxidase), and reducing oxidative damage (Rojas-Pirela et al., 2024; Abobatta, 2023). This improved stress tolerance translates into more stable yields under challenging environmental conditions.

   
   

5. Improvement of Soil Health: Chitosan can positively influence soil microbial communities, promoting the growth of beneficial microorganisms that contribute to nutrient cycling and disease suppression (Shahrajabian et al., 2021). It can also improve soil structure and water retention capacity, creating a more favorable environment for root growth and overall plant health.

   
   

Enhancing Crop Yield and Quality

The application of chitosan as a biostimulant has demonstrated significant potential in improving both the quantitative and qualitative aspects of crop production across various agricultural systems.

Increased Crop Yield

Numerous studies have reported that chitosan application leads to substantial increases in crop yields. This is attributed to its ability to promote vigorous vegetative growth, enhance flowering and fruit set, and improve nutrient use efficiency. For example, foliar application of chitosan has been shown to increase the biological and grain yield of wheat under limited irrigation conditions (Kocięcka et al., 2021). Similarly, in maize, chitosan application improved seed yield (Mondal et al., 2013). In horticultural crops like bell pepper, cucumber, lettuce, and carrot, chitosan has been observed to increase growth, development, germination, and overall yield (Reyes-Pérez et al., 2025). The use of chitosan nanoparticles, particularly when combined with other biostimulants, has further amplified these effects, leading to significant increases in plant height and overall biomass in crops like tomato (Munaro et al., 2024).

Improved Crop Quality

Golden wheat heads in a sunlit field showcase the enhanced yield and superior grain quality possible through chitosan biostimulant application.

Beyond yield quantity, chitosan plays a crucial role in enhancing the quality attributes of agricultural produce, which is vital for market value and consumer health.

1. Nutritional Content: Chitosan can boost the accumulation of valuable phytochemicals and nutrients in crops. Studies have shown increased levels of chlorophyll, carotenoids, flavonoids, and lycopene in fruits like tomatoes following chitosan treatment (Munaro et al., 2024). It can also enhance the nutrient content in various crops by acting as a carrier for slow-release delivery of ions (Nandini et al., 2025).

2. Post-Harvest Longevity: Chitosan's film-forming properties make it an excellent natural coating for fruits and vegetables, extending their shelf life. This coating reduces water loss, delays ripening, inhibits microbial spoilage, and maintains firmness, thereby preserving freshness and reducing post-harvest losses (Abobatta, 2023). This is particularly beneficial for perishable commodities, ensuring that high-quality produce reaches consumers.

3. Sensory Attributes: Chitosan application can positively influence the sensory characteristics of fruits, including taste, aroma, and texture, making them more appealing to consumers. For instance, chitosan derivatives have been shown to improve the fruit quality of kiwifruit (Hua et al., 2012) and enhance the accumulation of valuable phytochemicals in herbs like basil and lemon balm (Mohamed & Ahmed, 2013).

   
   

Future Prospects and Entoplast's Role

The continuous research and development in chitosan technology are paving the way for even more sophisticated and effective agricultural applications. Future innovations are likely to focus on tailored chitosan formulations, such as specific molecular weights or nanoparticle forms, to optimise their efficacy for different crops and environmental conditions. The integration of chitosan with other sustainable agricultural practices, including precision farming and integrated pest management, will further unlock its potential.

At Entoplast, we are at the forefront of harnessing the power of this extraordinary biopolymer. As a leading UK-based manufacturer of high-quality chitin and chitosan, we are committed to advancing sustainable agriculture through innovative solutions. Our dedication to rigorous research and development ensures that our products are not only of the highest purity and efficacy but also tailored to meet the evolving needs of the agricultural sector. We believe that chitosan is not just an additive but a fundamental component of future-proof farming, offering unparalleled benefits for crop yield, quality, and environmental stewardship.

We invite scientists, academics, and industry experts to partner with Entoplast. By collaborating with us, you gain access to premium-grade chitosan products and the expertise of a team dedicated to pioneering sustainable agricultural solutions. Contact Entoplast today to discuss potential collaborations or investments in our product lines, and together, let us cultivate a more productive and sustainable future for agriculture.