在加蓬（Gabon）的热带气候条件下，实现洋葱高产的关键在于选择适配品种、精准的肥水管理以及合理的避雨栽培。以下是针对2026年种植环境总结的高产栽培技术要点： 1. 品种选择与种子处理 适配品种：在加蓬，建议选用耐热、抗湿且对长日照要求不严的品种。最新的试验显示，ARES 和 Prema 品种在西非和中非的雨季表现出较强的适应性和耐储性。此外，Red Creole 和 Texas Grano 也是非洲热带地区的常用高产大果品种。 浸种催芽：播种前使用20°C-30°C的清水浸泡种子8-12小时，可显著提高发芽率。 2. 苗床管理（育苗期 6-8 周） 苗床准备：由于加蓬降雨丰富，必须使用高畦（Raised Beds）育苗，畦宽约1米，以防止积水导致烂根。 播种密度：每平方米建议播种约7克种子。播后覆盖薄草帘遮荫保湿，并防止暴雨冲刷，待7-14天出苗后及时移除覆盖物。 炼苗：移栽前7-10天，逐渐减少水分供应并增加光照，使幼苗变硬以适应田间环境。 3. 定植与规格 移栽标准：当幼苗生长到铅笔粗细（约5-6片叶）时进行移栽。 合理密植：高产的关键是保证植株密度。建议株距保持在7.5-10厘米，行距约15-20厘米。 4. 肥水管理 科学施肥： 基肥：定植前施用充分腐熟的有机肥（如4.5-6吨/公顷）和复合肥。 追肥：定植后3周开始追肥。在生长前期以氮肥为主促进叶片生长；鳞茎膨大期需增加钾肥和微量元素（如硼、锌），以提升鳞茎大小和品质。 水分控制：洋葱对缺水敏感，土壤含水量不应低于25%。在鳞茎膨大期（移栽后约60天）需保证充足水分，但收获前2周应停止灌溉以利于成熟和储藏。 5. 病虫害防治与管理 杂草控制：洋葱根系竞争力弱，需在生长早期通过手工除草或轻耕保持田间清洁。 病虫害监测：重点监测葱蓟马（Thrips）和紫斑病。在雨季，应使用避雨棚或定期喷施杀菌剂防止霜霉病。 轮作：避免与葱属植物（如大蒜、韭菜）连作，建议进行3-4年的轮作周期以减少土传病害。 6. 收获与后处理 收获信号：当70%-80%的植株叶片发黄萎蔫并倒伏时即可收获。 晾晒处理（Curing）：采收后需在阴凉通风处进行2-3周的晾晒，待表皮干燥、颈部收缩变硬后再行储存，这对于加蓬等高温高湿地区防止腐烂至关重要。 In Gabon's tropical climate, the key to achieving high onion yields lies in selecting suitable varieties, precise fertilizer and water management, and appropriate rain-sheltered cultivation. The following are key points for high-yield cultivation techniques summarized for the 2026 planting environment: 1. Variety Selection and Seed Treatment Suitable Varieties: In Gabon, it is recommended to choose heat-resistant, moisture-tolerant varieties that are not demanding in terms of long days. Recent trials show that the ARES and Prema varieties exhibit strong adaptability and storage tolerance during the rainy season in West and Central Africa. In addition, Red Creole and Texas Grano are also commonly used high-yielding, large-fruited varieties in tropical Africa. Seed Soaking and Germination: Soaking seeds in 20°C-30°C water for 8-12 hours before sowing can significantly improve the germination rate. 2. Seedbed Management (Seedling Period 6-8 Weeks) Seedbed Preparation: Due to Gabon's abundant rainfall, raised beds (approximately 1 meter wide) must be used for seedling cultivation to prevent waterlogging and root rot. Sowing Density: It is recommended to sow approximately 7 grams of seeds per square meter. After sowing, cover with a thin straw mat for shade and moisture retention, and to prevent damage from heavy rain. Remove the covering promptly after 7-14 days when seedlings emerge. Hardening Off: 7-10 days before transplanting, gradually reduce water supply and increase light exposure to harden the seedlings and allow them to adapt to the field environment. 3. Transplanting and Size Transplanting Standard: Transplant seedlings when they reach the thickness of a pencil (approximately 5-6 leaves). Reasonable Planting Density: Maintaining a high plant density is crucial for high yields. It is recommended to maintain a plant spacing of 7.5-10 cm and a row spacing of approximately 15-20 cm. 4. Fertilizer and Water Management Scientific Fertilization: Base Fertilizer: Apply fully decomposed organic fertilizer (e.g., 4.5-6 tons/hectare) and compound fertilizer before transplanting. Topdressing: Begin topdressing 3 weeks after transplanting. In the early growth stage, focus on nitrogen fertilizer to promote leaf growth; during the bulb enlargement stage, increase potassium fertilizer and trace elements (such as boron and zinc) to improve bulb size and quality. Water Control: Onions are sensitive to water shortage; soil moisture content should not be lower than 25%. Sufficient water is needed during the bulb enlargement stage (approximately 60 days after transplanting), but irrigation should be stopped 2 weeks before harvest to facilitate maturation and storage. 5. Pest and Disease Control and Management Weed Control: Onion roots are relatively weak, so manual weeding or light tillage is necessary to keep the field clean in the early growth stage. Pest and Disease Monitoring: Focus on monitoring for onion thrips and purple blotch. During the rainy season, use rain shelters or regularly spray fungicides to prevent downy mildew. Crop Rotation: Avoid continuous cropping with Allium species (such as garlic and leeks). A 3-4 year rotation cycle is recommended to reduce soil-borne diseases. 6. Harvesting and Post-Harvest Treatment Harvest Signal: Harvest when 70%-80% of the plants have yellowed, wilted, and fallen over. Curing: After harvesting, allow the plants to dry in a cool, well-ventilated place for 2-3 weeks until the outer skin is dry and the neck has shrunk and hardened before storing. This is crucial for preventing rotting in hot and humid regions such as Gabon.