Effects of tobacco (Nicotiana tabacum) applied with gibberellic acid (GA3) in response to different durations of drought and flooding

Abstract

Background and Objective: Tobacco (Nicotiana tabacum) is a major industrial crop used in cigars and cigarettes. Drought and flooding can significantly impact its growth. Gibberellic acid (GA3) explored its potential to enhance the resilience. Therefore, this study investigates the effects of GA3 on tobacco growth under varying drought and flooding conditions. Methodology: The study utilized 6 × 2 factorials in a randomized complete block design (RCBD) with three replications. Factor A included stress duration treatments: control (Con), drought for three days (D), prolonged drought for five days (PD), flood for three days (F), prolonged flood for five days (PF), flood followed by prolonged drought (F + PD), and prolonged flood followed by prolonged drought (PF + PD). Factor B involved gibberellic acid 3 (GA3) application, with B1 representing GA3 application (WG) and B2 without GA3 (WOG). Data was analyzed with two-way ANOVA. Treatment means differences assessed via Tukey’s HSD test. Main Results: Gibberellic acid 3 (WG) significantly influenced (P < 0.05) plant height (PH), number of leaves (NL), leaf length (LL), root length (RL), and biomass yield (BY), averaging 35.71 ± 2.34 cm, 5.00 ± 0.53, 31.14 ± 1.87 cm, 25.14 ± 1.42 cm, and 195.43 ± 7.65 g, respectively. Con + WG notably had significantly higher PH (63.00 ± 3.12 cm), NL (7.00 ± 0.53), LL (50.00 ± 2.34 cm), RL (36 ± 1.87 cm), and BY (255.65 ± 9.72 g). Different durations of drought and flooding stress conditions high significantly impaired tobacco growth, resulting in decreased PH from 60.00 ± 17.07 to 17.50 ± 7.79 cm and LL from 43.00 ± 8.60 to 17.50 ± 0.71 cm. Conclusions: GA3 application enhances tobacco growth, boosting plant height, leaf count, length, and biomass yield, counteracting water stress’s adverse effects. Water stress diminishes tobacco metrics like plant height, leaf area, and fresh weight.