Later fruit development stages require more potassium: Đầu Trâu Nuôi Trái 14-7-21 for durian, grapefruit, orange, mandarin, dragon fruit
Published · Út Nữ Co., Ltd
> Warning: The content of this article is generated/supported by AI based on publicly available documents. Út Nữ Co., Ltd disclaims responsibility for damages arising from the use of information in this article. Farmers and dealers should cross-reference packaging, manufacturer's instructions, local seasonal calendars, and contact the hotline for advice suitable for actual conditions. As fruits grow larger, many farmers ask why, despite applying a lot of nitrogen at the initial stage, the fruits later do not develop flesh or sweetness. The answer often lies in the fertilizer ratio: later fruit development stages require more potassium than nitrogen and phosphorus. Đầu Trâu Nuôi Trái 14-7-21 is a typical example: with a 14-7-21 formula, potassium is one and a half times higher than nitrogen. Đầu Trâu Nuôi Trái 14-7-21: What does the manufacturer state? According to the description by Bình Điền Fertilizer Joint Stock Company (n.d.):
- NPK fertilizer supplemented with sulfur and micronutrients, high potassium, in the form of uniform purple granules, dissolves quickly.
- Ingredients: Total N 14%, Available P₂O₅ 7%, Available K₂O 21%, S 7%; Cu 50 ppm, Zn 290 ppm, B 155 ppm, Mn 70 ppm; moisture 2.5%.
- Potassium in sulfate form (SOP) as printed on the bag.
- Instructions: “Fruit development stage: grapefruit, orange, tangerine, durian, avocado 0.5–1.5 kg/tree, apply 2–3 times; dragon fruit 0.3–0.5 kg/post/time, apply 1–2 times”.
- According to Bình Điền's description: supplemented with boron and zinc (Smart Zinc), contributing to limiting premature fruit drop and supporting fruit development; actual effectiveness depends on garden conditions.
- 20 kg bag, uniform purple granules, dissolves quickly (according to goods in stock).
Reading the formula: every 10 kg of fertilizer contains approximately 1.4 kg N, 0.7 kg P₂O₅, and 2.1 kg K₂O. High potassium is a distinguishing feature compared to balanced formulas like 16-16-16 or 20-20-15. In later fruit development stages, plants need potassium to transport sugars into the fruit, develop flesh, and enhance color; nitrogen is still needed but is no longer the main role. Dividing application times by plant type 1. Grapefruit, orange, tangerine, durian, avocado: 0.5–1.5 kg/tree, divided into 2–3 applications during the fruit development stage. For large trees with many fruits, use the higher end of the range; for small trees with fewer fruits, use the lower end. 2. Dragon fruit: 0.3–0.5 kg/post/time, apply 1–2 times. Illustrative example: a durian garden with 100 trees, each tree applied 1 kg/time, 2 times, the whole garden needs 200 kg, which is 10 bags of 20 kg. A dragon fruit garden with 500 posts, each post 0.4 kg/time, 2 times, needs 400 kg, which is 20 bags. These figures are for calculation practice only; application rates vary depending on soil type, variety, and growth conditions; read the instructions on the bag carefully. How to apply for plant absorption
- Apply according to the canopy projection, where there are many absorbing roots, not concentrated at the base.
- Lightly loosen or cover thinly, water sufficiently after application. In the early dry season, if the soil is dry, the fertilizer remains on the surface, making it difficult for plants to absorb.
- Divide into smaller applications instead of one large application: growing fruits need consistent nutrition.
- Coastal gardens: The Department of Crop Production and Plant Protection recommends storing fresh water and measuring salinity before irrigation (Dân Việt, 2026). The rainy season is forecast to end early, around October 25–November 10 (Thúy Lam, 2026), so mulch the base to retain moisture now.
Dealers advise farmers 1. What type of plant, how old, and what stage the fruit is in. 2. How many trees/posts to calculate the amount in kg per application. 3. How many times it has been applied since fruit set, to ensure the entire schedule falls within Bình Điền's guidelines. 4. Look for the correct Đầu Trâu Nuôi Trái 14-7-21 SOP bag, with uniform purple granules, 20 kg bag. Út Nữ Co., Ltd distributes wholesale in Vĩnh Long – Trà Vinh – Mekong Delta region; if you need to replenish stock, you can call / Zalo 0294 3882069 – 02943 883791 – 02943 882837. Conclusion Later fruit development stages require more potassium: Đầu Trâu Nuôi Trái 14-7-21 is recommended by Bình Điền at 0.5–1.5 kg/tree, 2–3 times for grapefruit, orange, tangerine, durian, avocado, and 0.3–0.5 kg/post/time for dragon fruit. Applying according to the canopy, watering adequately, and dividing applications are the correct ways to apply the right type, at the right time, and in the right amount for later fruit development. References Bình Điền (n.d.) *Đầu Trâu Nuôi Trái 14-7-21 SOP* (product description, ingredients, and usage instructions). Available at: https://binhdien.com (Accessed: 10 October 2026). Dân Việt (2026) 'Latest seasonal calendar to “avoid” El Nino-induced salinity for the 2026-2027 Winter-Spring crop, what does the Department of Crop Production and Plant Protection recommend?', *Báo Dân Việt*, 19 June. Available at: https://danviet.vn/khung-thoi-vu-moi-nhat-ne-han-man-do-el-nio-cho-vu-dong-xuan-2026-2027-cuc-trong-trot-va-bvtv-khuyen-cao-gi-d1436554.html (Accessed: 8 October 2026). Thúy Lam (2026) 'Guidance on seasonal calendar and rice variety structure for the 2026–2027 Winter-Spring crop', *Cà Mau Provincial Agricultural Extension Center*, 6 October. Available at: http://khuyennongcamau.vn/thong-tin-va-truyen-thong/huong-dan-lich-thoi-vu-va-co-cau-giong-lua-vu-dong-xuan-2026-2027-85460 (Accessed: 8 October 2026). About content and responsibility Content developed by Grokbot AI. Út Nữ Co., Ltd and Grokbot AI disclaim responsibility for any damages arising from the use of information in this article. All content is for exploratory and academic purposes only, does not replace professional technical advice, official recommendations from manufacturers or state agencies, and does not constitute a commercial promise of yield or economic efficiency.