Table 1 Key causes of premature senescence in Bt cotton
From: Premature senescence in Bt Cotton: understanding the mechanisms and control measures
Category | Contributing factors | Examples/details |
|---|---|---|
Genetic factors | Specific genotypes with reduced root vigor, inefficient nutrient remobilization | Some Bt cotton varieties are inherently more prone to senescence under stress due to their genetic makeup (e.g., weak root systems) |
Physiological disorders | Imbalances in source-sink relationships, root-shoot allocation issues | Increased boll load leads to poor nutrient allocation to roots, impairing development and causing senescence (Chen et al. 2016) |
Environmental influences | Drought, high temperatures, waterlogging, salinity, and other abiotic stresses | Stress conditions disrupt physiological processes and accelerate aging (Zhu et al. 2023; Ahmed et al. 2024) |
Nutrient deficiencies | Imbalances in nitrogen, potassium, phosphorus, and trace elements | Potassium deficiency is particularly critical, affecting photosynthesis and stress resistance (Wang et al. 2022; Tian et al. 2024) |
Hormonal imbalance | Endogenous hormones affecting senescence (ethylene, cytokinin, auxin, gibberellin, etc.) | Ethylene and abscisic acid promote senescence, while cytokinin delays it (Chen et al. 2016; Zhang et al. 2021) |
Agronomic practices | Improper fertilization, excessive nitrogen, low planting density, poor crop management | Excessive vegetative growth, nutrient imbalances, and suboptimal planting practices exacerbate senescence (Chen et al. 2016) |