High-Yield and High-Efficiency Cultivation Techniques for Export-Oriented White Sesame

China's annual sesame export volume has remained at around 90,000 tons, accounting for 15% of total global exports, giving sesame exports a strong advantage. Since last year, due to strong consumer demand from Japan, South Korea, Europe and the United States, the price of pure white sesame on the international market has gradually risen, with high-quality sesame exceeding 1,000 USD/ton. According to relevant data analysis, the sesame market is stabilizing, and developing export-oriented white sesame production offers considerable benefits. The key high-yield and high-efficiency cultivation techniques are as follows.

1 Site selection: select sites far from industrial and mining enterprises (more than 5 km away), free of industrial "three wastes," with abundant light and heat resources and diverse ecological environments. The environmental quality of air, water, soil, etc. must comply with the environmental quality standards for pollution-free agricultural product production bases. The land should be sandy loam and light loam with high, dry terrain, good irrigation and drainage, fertile soil and loose texture.

2 Variety selection: choose white-skinned sesame varieties such as "Zhongzhi No. 11 and No. 12" and "Ezhi No. 3."

3 Cultivation techniques

Crop rotation: the root exudates of sesame are beneficial to cereal crops but harmful to soybean and sesame, and can easily cause serious diseases. Therefore, sesame should be reasonably rotated with sorghum, corn or millet, preferably once every 3 years.

Land preparation: sesame is a dicotyledonous plant with small seeds and weak soil-emergence ability. Before sowing, fine land preparation should be carried out, with plowing, harrowing and rolling to preserve soil moisture, removing stubble and breaking up clods so that the soil is fine and crumbly.

Fertilization: the root layer of sesame is shallow, and shallow application of base fertilizer gives good yield-increasing results. Seed fertilizer can be mixed with seeds for sowing, or broadcast in sowing furrows or holes. Generally, apply 5-8 kg of cake fertilizer per mu, or 3-4 kg of potassium sulfate or 300-400 kg of farmyard manure. Topdressing should be applied in stages at the seedling stage, bud stage and full flowering stage. During flowering, spray a 0.4% potassium dihydrogen phosphate solution on sunny afternoons, once every 5-6 days, for 2-3 consecutive times; if rain occurs, re-spray, so as to increase capsule number, increase grain weight and raise oil content.

Timely sowing: spring sesame is best sown in early May, and summer sesame in early June, with a sowing rate of about 0.5 kg per mu. Drilling is the better sowing method for sesame. Before sowing, use 12.5% tepraloxydim or 2.5% pendimethalin for seed dressing, which gives more obvious disinfection and disease prevention effects. Sesame should be sown shallowly, with a sowing depth of 1-2 cm; when soil moisture is insufficient, sow slightly deeper and cover with shallow soil. After sowing, press promptly so that the seeds are in close contact with the soil, which helps the seeds absorb water, germinate and emerge.

Reasonable close planting: generally, single-stem varieties should be planted more densely than branching varieties, and varieties tolerant to poor soil and widely adaptable should be appropriately planted densely; spring sowing should be thinner than summer sesame. For single-stem varieties, the row spacing should be 40-44 cm, with an average of 12,000 plants retained per mu, and 15,000 plants per mu on sloping land; for branching varieties, the row spacing should be 42-44 cm, with an average of 10,000 plants retained per mu, and 12,000 plants per mu on sloping land.

Strengthen field management. ① Early thinning and early final thinning can avoid crowding of seedlings and competition for water, fertilizer and light. Thin when 1 pair of true leaves appears, and final-thin when 2-3 pairs of true leaves appear. During final thinning, transplanting can be combined to fill gaps; before transplanting, irrigate thoroughly so that the seedling roots closely combine with the soil, allowing transplanting with soil. ② Intertillage and earthing up. Generally, carry out intertillage once each at the 1 pair of true leaves stage, the 2-3 pairs of true leaves stage and the branching stage. If high temperature and rainy weather occur, follow the rule of "hoe after every rain, hoe whenever there are weeds" to prevent weed overgrowth and seedling overcrowding. Combine the last intertillage with earthing up to cover the roots, so as to facilitate drainage and irrigation and prevent waterlogging damage and drought. ③ Timely topping to reduce ineffective flowers. Promote the double-stem cultivation technique for single-stem sesame: at the seedling stage, remove the main stem growing point to induce axillary buds to sprout and form stem sesame. That is, for spring-sown sesame retain the first pair of true leaves, and for summer-sown sesame retain the second pair of true leaves; when the retained leaves are half-unfolded and the internode below the half-unfolded leaf has elongated by about 5 mm, remove the half-unfolded leaf and the main stem growing point, and after pinching keep 2-3 mm of stem node above the retained leaves. At the late full flowering stage, remove the top growing tip about 1 cm from the top. Immediately after topping, spray a mixture of 800-fold carbendazim and 0.3% potassium dihydrogen phosphate once, which can improve the photosynthetic efficiency of sesame leaves in the later stage, delay leaf senescence, increase grain weight and raise yield. ④ Pest and disease control. First, weeds at the edges of sesame fields must be eradicated to eliminate overwintering hosts. In combination with spring land preparation, capture and kill overwintering pests; to control cutworm larvae over the 3rd instar, carry out manual capture in the morning and evening. Use fully decomposed fertilizer to reduce egg parasitism. Use light trapping to kill adults; promptly and effectively control sesame seedling damping-off, stem spot blight, bacterial wilt and fusarium wilt. ⑤ Harvesting and threshing. When 1-2 capsules at the lower part of the plant crack slightly and the seeds in the middle and upper capsules reach the original seed color, harvest promptly, bundle, dry in the sun and thresh. Thresh and store separately to prevent variety mixing and inconsistency in seed coat color, which would affect export quality.