The aim of this study was to find the optimal gibberellic acid (GA₃) and copper sulfate (CuSO₄·5H₂O) concentrations to reduce the number of seeds and increase the quality of Bac Son mandarin fruit. In experiment 1, the control plants (without GA₃) were sprayed with water, and the remaining plants were sprayed with different concentrations of GA₃ (50, 75, 100, or 125 ppm). In experiment 2, the control plants (without CuSO₄·5H₂O) were sprayed with water, and the remaining plants were sprayed with different concentrations of CuSO₄·5H₂O (50, 75, 100, or 125 ppm). Spraying GA₃ at 100 ppm in 2018 produced the lowest seed number and the highest theoretical yield. In 2019, spraying GA₃ led to a lower seed number and a higher actual yield compared with the control. Similarly, spraying CuSO₄·5H₂O significantly reduced the number of seeds/fruit and significantly increased the theoretical yield in 2018. In 2019, the total number of seeds/fruit was significantly lower in the CuSO₄·5H₂O treatments than in the control. Importantly, both GA₃ and CuSO₄·5H₂O treatments did not adversely affect the fruit’s biochemical parameters or yield. These findings demonstrate that spraying GA₃ or CuSO₄·5H₂O at a certain concentration can effectively reduce the number of seeds per fruit in Bac Son mandarin without compromising fruit quality or yield.

Background: Vietnam is experiencing a significant “double burden” of malnutrition, characterized by the persistent challenge of undernutrition, particularly stunting in ethnic minority and mountainous regions, alongside a rising prevalence of overweight and obesity. Understanding dual nutritional status and its related factors in adolescents from these vulnerable areas is crucial for effective intervention. Objective: The current study explored the nutritional status of ethnic minority secondary school students in some mountainous provinces in the northwest of Vietnam and identified some related factors. Methods: We conducted a cross-sectional study over six months (June–December 2023), involving 1847 ethnic minority high school students from Son La and Dien Bien provinces, recruited through convenience sampling in primary healthcare settings. Nutritional status was determined using WHO 2006 Child Growth Standards, specifically height-for-age Z-scores (HAZ) and body mass index (BMI)-for-age Z-scores (BAZ). A 4-point scale assessed nutritional practices, including food consumption frequency and eating habits. Results: This study identified a stunting (HAZ < −2 SD) prevalence of 16.7% and wasting (BAZ < −2 SD) of 5.6%; overweight/obesity (BAZ > +1 SD) prevalence was 8.2%. Key factors related to stunting were being male, having more siblings, poor/near-poor household economic status, low maternal education level, and frequent occurrences of gastrointestinal and respiratory diseases. A higher risk of overweight/obesity was associated with consuming more than three meals daily, nocturnal snacking, frequent intake of fried foods, insufficient consumption of vegetables and fruits, and inadequate daily physical activity. Conclusions: Our study shows a comprehensive picture of malnutrition among children in ethnic minority areas. Essential nutritional intervention programs, projects, and models are a top priority to reduce the disease burden for children’s bright future and to enhance socio-economic development in the mountainous regions of Vietnam.

Background: Malnutrition among Vietnamese children, especially children in ethnic minority and mountainous areas, remains high. Objective: The current study explored the nutritional status of ethnic minority secondary school students in some mountainous provinces in the Northwest of Vietnam and identified some related factors. Methods: We recruited 1,847 high school students who are ethnic minorities in 2 provinces of the northwestern mountainous region of Vietnam by convenience sampling from a primary healthcare setting to carry out the cross-sectional study over 6 months. The malnutrition status of study participants was measured using the 2006 WHO Child Growth Standards. The nutritional practices of study participants were assessed using a 4-point scale based on food consumption frequency and eating habits. Results: This study found that the prevalence of stunting and wasting in children was 16.7% and 6.2%, respectively, while the prevalence of overweight/obesity in children was 8.3%. Some factors related to the rate of stunting are male students, the number of children born living in the family, poor/near-poor household economy, low maternal education level, and frequent gastrointestinal and respiratory diseases. Children who ate more than 3 meals/day, snacked at night, ate fried foods, ate less vegetables and fruits, and were less active/day were associated with a higher risk of overweight/obesity. Conclusions: Our study shown a comprehensive picture of malnutrition among children in ethnic minority areas. Essential nutritional intervention programs, projects and models are a top priority to reduce the disease burden, for children’s bright future and to enhance socio-economic development in the Northwest mountains.