Growth, Yield and Biochemical Qualities of Spinach (Spinacia oleracea) being Influenced by the Foliar Application of Chitosan

The study was carried out to evaluate the effects of various doses of foliar application of chitosan on spinach growth, yield, and quality characteristics (including chlorophyll-a, chlorophyll-b, total chlorophyll, carotenoids, total ash, and main nutrient contents). The Randomized Completely Block Design (RCBD) was used to set up the field experiment, with six treatment combinations [T0 = Control (no chitosan application), T1 = 100 ppm chitosan solution, T2 = 150 ppm chitosan solution, T3 = 200 ppm chitosan solution, T4 = 250 ppm chitosan solution, and T5 = 300 ppm chitosan solution] and three replications. The results revealed that applying chitosan at different doses significantly affected growth (viz., plant height, the number of leaves per plant) and yield of spinach. Moreover, due to the application of chitosan at various doses, there were notable differences observed in chlorophyll, total phenol, and ash contents of spinach. The spinach sample contained an average of 13.61–15.82 mg per g of chlorophyll–a, 9.16–10.18 mg per g of chlorophyll–b, and 22.77–25.85 mg per g of total chlorophyll. On the contrary, the effect of foliar application of chitosan at different doses showed a statistically significant difference in the P, K, Zn, and Fe contents of spinach. The highest amounts of chlorophyll-a, total ash, P, and K in spinach were obtained from treatment T3. However, the results showed that most of the biochemical properties of spinach were reduced by the higher doses (treatments T4 and T5) of foliar application of chitosan. Finally, according to the study's findings, foliar application of chitosan at the rate of 200 ppm significantly affects the growth, yield, pigments, total ash, P, and K contents of spinach.