Bioscience Methods 2026, Vol.17, No.1, 43-56 http://bioscipublisher.com/index.php/bm 43 Research Insight Open Access The Effects of Different Potassium Fertilizer Application Rates on Sweet Potato Yield, Dry Matter Content and Sugar Accumulation Yanhong Zhong1,2 1 Kaihua Wohua Family Farm, Kaihua, 324304, Zhejiang, China 2 Zhejiang Agronomist College, Hangzhou, 310021, Zhejiang, China Corresponding author: 407292539@qq.com Bioscience Methods, 2026, Vol.17, No.1 doi: 10.5376/bm.2026.17.0005 Received: 09 Jan., 2026 Accepted: 10 Feb., 2026 Published: 22 Feb., 2026 Copyright © 2026 Zhong, This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Preferred citation for this article: Zhong Y.H., 2026, The effects of different potassium fertilizer application rates on sweet potato yield, dry matter content and sugar accumulation, Bioscience Methods, 17(1): 43-56 (doi: 10.5376/bm.2026.17.0005) Abstract Sweet potatoes are a typical potassium-loving crop. Achieving a simultaneous increase in both high yield and high quality is of great significance for the sweet potato industry. However, the current production practice, which focuses on yield while neglecting quality, leads to limited improvement in the stability of yield and the quality of sweet potato tubers. This study focuses on the regulation of potassium fertilizer dosage to achieve a coordinated improvement in yield and quality of sweet potatoes. By setting different potassium fertilizer gradients (with consistent nitrogen and phosphorus supply and staged potassium application), the yield, dry matter rate, sugar components, and related physiological indicators were systematically observed. A multi-objective comprehensive evaluation was used to select the optimal potassium application strategy. The results show that an appropriate amount of potassium fertilizer can significantly increase the yield and commercial rate of sweet potato tubers, promote the accumulation of dry matter and starch, and increase the sucrose content of tubers, thereby achieving a balance between yield and quality. Insufficient potassium application limits yield due to insufficient nutrient supply and the poor flavor of tubers; excessive potassium application leads to a slower increase in yield and a decrease in fertilizer utilization rate. Mechanism analysis reveals that potassium enhances photosynthesis and the distribution of assimilates to the tubers, accelerating starch synthesis and sugar accumulation to simultaneously improve yield and quality. Based on the evaluation of all indicators, this study determined the appropriate range of potassium application for high-yield and high-quality sweet potatoes and proposed a fertilization strategy of "staged potassium application + goal-oriented", which can provide guidance for sweet potato production. Keywords Sweet potato; Potassium fertilizer application; Dry matter ratio; Sugar composition; Yield and quality 1 Introduction Sweet potatoes are an important food and industrial raw material crop in China, widely cultivated due to their wide adaptability and tolerance to poor soil conditions (Etana et al., 2019). With the upgrading of residents' consumption and the development of the processing industry, the market has put forward the requirement of both high yield and high quality for sweet potatoes (Sharmin et al., 2024). Achieving the coordinated improvement of sweet potato yield and quality is not only related to farmers' income increase and industrial competitiveness, but also to food processing and health consumption demands. However, there is currently a problem of unbalanced fertilization in production: farmers often focus on nitrogen fertilizer input while neglecting potassium fertilizer supplementation, resulting in insufficient potassium supply in the soil, which becomes a key factor limiting the stable yield and quality improvement of sweet potatoes (Walter et al., 2011). Therefore, it is urgent to clarify the mechanism of potassium fertilizer management on the yield and quality of sweet potatoes, and to formulate fertilization strategies that balance high yield and high quality to meet the needs of the sustainable development of the sweet potato industry (Aboyeji et al., 2019). Potassium is one of the key nutrient elements required for the growth and development of sweet potatoes (Lv et al., 2021). Throughout the entire growth period, sweet potatoes have a higher demand for potassium than for nitrogen and phosphorus. Especially during the period of tuber enlargement, a large amount of potassium supply is needed. An appropriate level of potassium nutrition is an important guarantee for achieving high yields (Geng et al., 2024). Potassium acts as an activator for various enzymes in sweet potatoes, which can enhance the intensity of photosynthesis in leaves and the transport capacity of assimilates, and strengthen the plant's resistance and storage
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