Analysis of Key Points for High-Yield Cultivation Techniques of Black Sesame

There are many varieties of black sesame, and "Zhongzhi No. 9", bred by the Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, is the primary variety. This variety is of the branching type, with a yield of up to 58.33 kg per mu. The growth period for summer sowing is 95 days. The seed coat is jet black, and the 1000-grain weight is 2.63 g. The oil content reaches 47.3%, and the protein content is above 21%. This variety has strong resistance to stem blight and is a variety worth promoting.

At present, sesame cultivation mainly adopts the "double-stem cultivation method". In this method, the growing tip is removed when the third pair of true leaves of the sesame seedling is half-unfolded, so that the axillary buds of the first (or second) pair of true leaves sprout and grow, forming double stems. To adopt this method, the following points should be mastered:

1. Seed dressing with chemicals, crop rotation, and early sowing by seizing soil moisture. Before sowing, 8 g of 50% carbendazim wettable powder or 40% carbendazim suspension concentrate can be mixed with 0.5 kg of water into a paste and stirred evenly with 0.5 kg of seeds, ready for sowing. Sesame should not be planted continuously; a 4-year 2-crop rotation system is advocated. Make the most of good preceding crops and sow early.

2. Sow early at the appropriate time and control density. For summer sesame, the sowing date should be no later than June 15, and generally the earlier the better. The cultivation density is generally suitable at 8000-10000 plants per 667 sq m.

3. Strictly master the timing and method of topping. For summer sesame, retain 2 pairs of true leaves for topping, and retain 2-3 cm of stem nodes above the leaves. In the same field, keep the standard for retained true leaves consistent, and complete topping in one pass.

4. Pay attention to supplementary seedling fertilizer. After topping sesame, to prevent nutrient deficiency in the new branches, a suitable amount of quick-acting fertilizer can be applied; when the new branches grow the second and third pairs of true leaves, spray 100-fold mepiquat chloride or paclobutrazol solution to prevent later lodging and increase the number of effective capsules.

5. Prevent waterlogging, manage early, and prevent weed infestation. When planting, first open the bed furrows and surrounding furrows. Generally, the bed surface width is 2-2.5 m, the bed furrow depth is 0.3 m, and the surrounding furrow depth is 0.4-0.5 m. The layout of furrows and beds depends on the terrain and soil quality, and in flat areas waist furrows should also be made. When the seedlings grow 2-3 pairs of true leaves, thin them to a fixed stand, with a row spacing of 36 cm × 12-15 cm, and cultivate and weed once. When the seedlings are 33 cm tall, earth up in combination with topdressing.

6. Fertilize scientifically and prevent diseases and pests. Because summer sesame has a short growth period and requires much fertilizer in a concentrated way, basal fertilizer should be the main application. Apply about 15 kg of ammonium bicarbonate per mu, plus 30-40 kg of phosphate fertilizer and about 6-8 kg of potassium fertilizer. During the growth period, for fields with sparse seedlings and weak growth, 3-5 kg of urea can be topdressed per mu. At the jointing stage, to prevent angular leaf spot and leaf blight, spray leaves twice with 1000-fold 50% iprodione solution. If aphids occur, spray with imidacloprid.