**3.6 Chitosan-Cu nanocomposites (Ch-CuNCs)**

Copper (Cu) is one of the most important nutrients in plants. Although excessive use of Cu is harmful to all plants, Cu is allowed for organic farming. There are several reported copper-based fungicides. Various formulas are designed for the successful absorption of Cu by plants. It acts as an elicitor in plant cells to accelerate enzymatic activity. In other compounds, chitosan-copper nanocomposites (Ch-CuNCs) have also been tested for their antifungal activity in tomato inhibitors; Alternaria solani and Fusarium oxysporum. TEM, SEM-EDS, AAS-TEM, and SEM micrographs successfully demonstrated the inclusion of Cu in the chitosan matrix. Ch-CuNCs inhibits 70.5% and 73.5% mycelia growth and 61.5 and 83.0% algae growth rate in Alternaria solicit and Fusarium oxysporum, respectively. Plant lesion control was demonstrated when a significant decrease was observed in nano formulation-treated plants. The percentage efficacy of disease control (PEDC) success rate for Ch-Cu was recorded as 87.7%. In another report, Ch-Cu nanocomposite has shown significant antifungal activity against Sclerotium rolfsii and Rhizoctonia solani. The synthesized compound shows a means diameter of around 2–3 nm and is shown to be evenly distributed in nanocomposite uniforms. The results showed excellent results for the prevention of tested fungal diseases. Nanoparticles synthesized in acetone, produced a much higher degree of inhibition compared to those inferred by using toluene solvent. Jaiswal et al. synthesized Ch-CuNCs by adding copper sulfate to a chitosan solution followed by the incorporation of NaOH. The size of the copper particles produced was recorded as 700–750 nm. The solution is applied to plants referred to as a fungicide. The results revealed an important protective effect built against fungal pathogens. Chitosan-Cu nanocomposite has also been shown to be an important growth promoter in a variety of plants that performs Ch-Cu nano formulation and is combined with maize seedlings. Nano formulation has shown promising effects on plant growth by reducing the activity of α-amylase and protease enzyme and increasing the amount of protein content in seed germination (see **Figure 2**).

#### **Figure 2.**

*Flow chart diagram for the synthesis of nanocomposites.*

*Recent Progress and Overview of Nanocomposites DOI: http://dx.doi.org/10.5772/intechopen.102469*
