Detailed Explanation of Key Points for High-Yield Cultivation Techniques of Black Sesame

There are many varieties of black sesame. "Zhongzhi No. 9", bred by the Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, is the foremost 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, with a 1000-grain weight of 2.63 grams. The oil content reaches 47.3%, and the protein content is over 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". This method mainly involves removing the growing tip 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 changing plots, and sowing early to seize soil moisture. Before sowing, 8 grams 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 rotation system of 2 crops in 4 years is advocated. It is best to seize a good preceding crop and sow early.

2. Sow early at the appropriate time and master the density. The sowing period for summer sesame 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 node above the leaves. In the same field, the standard for retaining true leaves should be consistent, and topping should be completed in one go.

4. Pay attention to supplementary application of seedling fertilizer. After topping sesame, to prevent nutrient deficiency in the newly grown branches, a suitable amount of quick-acting fertilizer can be applied as a top dressing; when the newly grown branches produce the second and third pairs of true leaves, 100-fold diluted mepiquat chloride or paclobutrazol should be sprayed to prevent lodging later and increase the number of effective capsules.

5. Prevent waterlogging, carry out early intertillage and early management, 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 arrangement 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 spacing, with row spacing of 36 cm x 12-15 cm, and carry out one intertillage and weeding. When the seedlings are 33 cm tall, combine top dressing with earthing up.

6. Scientifically apply fertilizer and prevent diseases and pests. Because summer sesame has a short growth period and requires much fertilizer in a concentrated manner, it is advisable to apply base fertilizer mainly. Apply about 15 kg of ammonium bicarbonate per mu, plus 30-40 kg of phosphate fertilizer and about 6-8 kg of potash fertilizer. During the growth period, for fields with sparse seedlings and weak growth, 3-5 kg of urea can be applied per mu as a top dressing. At the jointing stage, to prevent angular leaf spot and leaf blight, 50% iprodione 1000-fold dilution can be sprayed on the leaves twice. If aphids occur, imidacloprid can be used for spraying.