Tree Genetics and Molecular Breeding 2025, Vol.15, No.4, 147-153 http://genbreedpublisher.com/index.php/tgmb 148 means conducting retraction pruning twice a year. This method can make the branches thicker and have more leaves, laying the foundation for large fruits to grow in the second year (Su et al., 2024). When pruning, cross branches, diseased and insect-infested branches, and weak branches should also be removed. Then, based on the number of branches, an appropriate amount should be retained to ensure good ventilation and light for the tree. 2.2 Effects on shoot maturation, flower bud differentiation, and carbohydrate accumulation Pruning in autumn can make new shoots grow faster and mature well, and also promote flower bud differentiation. Research has found that vigorous new shoots are more conducive to cell division and flower bud formation, thereby affecting the size and yield of fruits (Su et al., 2024). After pruning, the diameter of the central branches will increase, the leaves will be thicker, the internodes will be shorter, the quality of the fruiting mother branches will be higher, and the weight and sugar content of the single fruit will also increase. In addition, pruning helps accumulate more carbohydrates, storing energy for the development of flower buds and fruits in the following year. 2.3 Impacts on disease management and canopy microclimate Reasonable autumn pruning can also improve the canopy structure, enhance ventilation and light conditions, and reduce pests and diseases. By adjusting the main branch Angle and branch distribution, the light distribution in the tree canopy can be made more uniform, the photosynthetic efficiency can be improved, and the microclimate environment in the garden can be enhanced (Tang et al., 2019). This can not only improve the quality of the fruit, but also facilitate daily management and pest control. 3 Nitrogen-Potassium (N-K) Ratio Regulation Principles 3.1 Roles of nitrogen and potassium in vegetative and reproductive growth Nitrogen (N) can promote the growth of loquat branches and leaves, enhance the photosynthesis of leaves, drive the growth of branches and leaves, and increase the biomass of the plant. Potassium (K) plays a significant role in regulating water metabolism, enhancing stress resistance, promoting carbohydrate transport and improving fruit quality (Huang et al., 2020; Ali et al., 2021). Proper combination of nitrogen and potassium can enable loquat to maintain a balance between vegetative growth and reproductive growth, and increase yield and fruit quality (Yang et al., 2023; Zhao et al., 2024). Zhang et al. (2025) recently proposed that excessive application of nitrogen or potassium could disrupt the nutritional balance, affect the diversity of arbuscular mycorrhizal fungi (AMF), and influence the rhizosphere microecology and nutrient absorption. 3.2 Seasonal dynamics of nutrient demand in loquat trees In spring and summer, new shoots and leaves grow rapidly, and the demand for nitrogen in loquats will increase significantly. During the fruit expansion and ripening stages, loquat has a significantly increased demand for potassium, which is beneficial for fruit development and flavor enhancement (Yang et al., 2023). Soil moisture and climatic conditions can also affect the availability and absorption efficiency of nitrogen and potassium. Hu et al. (2023) and Zhao et al. (2024) both hold that fertilization should be flexibly adjusted in accordance with seasonal changes and environmental conditions. 3.3 Common fertilization strategies to achieve target N-K ratios Precision fertilization is the core to controlling the N-K ratio well (Gomes et al., 2020; Xu et al., 2020). Common methods include: applying nitrogen and potassium fertilizers in stages and in appropriate amounts based on soil nutrient testing and the growth stage of loquats. Combined with the spatial distribution of available nitrogen and available potassium in the soil, focus on supplementing the deficient nutrients (Zhao et al., 2024). Meanwhile, excessive fertilization should be avoided and bio-fertilizers (such as bio-fertilizers containing AMF) should be used appropriately to improve nutrient utilization rate and soil ecological stability (Zhang et al., 2025). In actual management, it is recommended to dynamically adjust the nitrogen-potassium ratio in combination with soil testing, weather conditions and the growth cycle of loquats to achieve high-yield, high-quality and sustainable production (Hu et al., 2023).
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