A Review of Potassium Use Efficiency in Banana Plants Under Flooding Conditions

Abstract

Banana (Musa spp.) is a staple food and cash crop in tropical and subtropical regions, but its production is severely constrained by flooding stress, which has become increasingly frequent due to climate- induced extreme weather. Waterlogging is a major abiotic stress affecting plant growth and productivity. Regardless of rainfall or irrigated environments, plants frequently face waterlogging, which may range from short-term to prolonged durations. Excessive precipitation and soil moisture disrupt crop growth, not because of the water itself but due to oxygen deficiency caused by water saturation. This lack of oxygen triggers a cascade of detrimental effects. Potassium (K), the most abundant cation in banana tissues (3-4% of dry weight), plays critical roles in osmotic regulation, stomatal function, enzyme activation, and stress tolerance. Potassium is the third macronutrient required for plant growth, after nitrogen and phosphorus and carries out vital functions in metabolism, growth and stress adaptations. The important functions in which potassium is involved with the plant are enzyme activation, cation/anion balance, stomatal movement, assimilate translocation and turgor regulation. However, potassium use efficiency (KUE) in banana under flooding stress remains poorly characterized. The review synthesizes current knowledge on the physiological and biochemical responses of banana to flooding stress. The role of potassium in mitigating flooding induced damage, genotypic variations in KUE, and strategies for optimizing potassium management in flood-prone environments. Key findings indicate that flooding reduces root respiration, photosynthetic capacity, chlorophyll content, and nutrient uptake while inducing oxidative stress and hormonal imbalances. Potassium application mitigates these effects by maintaining stomatal conductance, enhancing antioxidant enzyme activities, preserving photosynthetic pigments, and improving root system architecture. Genotypic variation in KUE is linked to differences in root morphology, K uptake kinetics, and the ability to form aerenchyma and radial oxygen loss barriers. ABB genomic group cultivars exhibit superior flooding tolerance compared to AA, AAA, and AAB genotypes. This review identifies critical knowledge gaps and proposes future research directions to improve banana productivity in flood-prone areas through optimized K nutrition. Key words: antioxidant, banana, condition, efficiency, flooding potassium, Genotypic variation

Banana (Musa spp.) is a staple food and cash crop in tropical and subtropical regions, but its production is severely constrained by flooding stress, which has become increasingly frequent due to climate- induced extreme weather. Waterlogging is a major abiotic stress affecting plant growth and productivity. Regardless of rainfall or irrigated environments, plants frequently face waterlogging, which may range from short-term to prolonged durations. Excessive precipitation and soil moisture disrupt crop growth, not because of the water itself but due to oxygen deficiency caused by water saturation. This lack of oxygen triggers a cascade of detrimental effects. Potassium (K), the most abundant cation in banana tissues (3-4% of dry weight), plays critical roles in osmotic regulation, stomatal function, enzyme activation, and stress tolerance. Potassium is the third macronutrient required for plant growth, after nitrogen and phosphorus and carries out vital functions in metabolism, growth and stress adaptations. The important functions in which potassium is involved with the plant are enzyme activation, cation/anion balance, stomatal movement, assimilate translocation and turgor regulation. However, potassium use efficiency (KUE) in banana under flooding stress remains poorly characterized. The review synthesizes current knowledge on the physiological and biochemical responses of banana to flooding stress. The role of potassium in mitigating flooding induced damage, genotypic variations in KUE, and strategies for optimizing potassium management in flood-prone environments. Key findings indicate that flooding reduces root respiration, photosynthetic capacity, chlorophyll content, and nutrient uptake while inducing oxidative stress and hormonal imbalances. Potassium application mitigates these effects by maintaining stomatal conductance, enhancing antioxidant enzyme activities, preserving photosynthetic pigments, and improving root system architecture. Genotypic variation in KUE is linked to differences in root morphology, K uptake kinetics, and the ability to form aerenchyma and radial oxygen loss barriers. ABB genomic group cultivars exhibit superior flooding tolerance compared to AA, AAA, and AAB genotypes. This review identifies critical knowledge gaps and proposes future research directions to improve banana productivity in flood-prone areas through optimized K nutrition. Key words: antioxidant, banana, condition, efficiency, flooding potassium, Genotypic variation