Effects of biochar treatments on the elemental composition of tobacco (Nicotiana tabacum L.) leaves based on the priming period

Heliyon. 2023 Dec 4;10(1):e23307. doi: 10.1016/j.heliyon.2023.e23307. eCollection 2024 Jan 15.

Abstract

This study determined the effects of different doses of biochars (B) on Virginia tobacco (Nicotiana tabacum L.) cultivar, on first and second harvest dependent change in plant nutrients (N, P, K, Ca, Mg, Cl, Zn, Fe, Mn, Cu, and B), leaf color parameters (L*, a*, and b*), chlorophyll value (SPAD), electrolyte leakage (EL), crude ash, number of leaves, and plant height. Pot experiments were conducted with biochar treatments of 10 tons ha-1 (B1), 20 tons ha-1 (B2), 40 tons ha-1 (B3), and 80 tons ha-1 (B4). Tobacco leaf macroelement (N, P, K, Ca, and Mg) levels increased with increasing biochar doses. The highest values were obtained for B4 treatments (80 tons ha-1) and the lowest for control (B0) treatments. Microelements (Fe, Zn, Mn, and B) exhibited a non linear change, while Cl and Cu exhibited a linear change. Color parameters (L*, a*, and b*) for the first and second priming showed the highest L* and b* values for B2 and B3 treatments, respectively, and the highest a* values for the B2 treatment. Leaf SPAD values increased with increasing biochar doses; further, the obtained SPAD values were ordered as B4 > B3 > B2 > B1 > B0. Leaf electrolyte leakage values were 25.90 %-37.25 % in the first priming and 26.90 %-40.59 % in the second priming. For both the primings, the highest crude ash values (21.94 % and 19.05 %) were observed for the B4 treatments, whereas the lowest values (17.89 % and 17.01 %) were observed for the B0 treatments. the tallest plant height (121.9 cm) and the highest number of leaves (45.3) were determined in B4 applications. Overall, considering the nutrition and quality of tobacco, B2 application is recommended.

Keywords: Biochar; Color parameter; Plant nutrient; SPAD; Tobacco (Nicotiana tabacum L.).