Key Production Techniques for Green Agricultural Product Sesame

1. Base selection: Within the surrounding area (within 2000 m) of the green agricultural product sesame production base there are no pollution sources; the atmospheric environment conforms to the air quality of a green food base; the farmland irrigation water quality conforms to the irrigation water quality standards of a green food base; and the farmland soil quality conforms to the environmental standards of a green food base.

2. Variety selection: Liaozhi No. 1, Liaozhi No. 2, Batongbai, etc.

3 Main cultivation techniques

3.1 Crop rotation and stubble change, sowing early at the right time to capture soil moisture

According to research, the root system of sesame can secrete a substance, and this secreted substance remains in the soil after the sesame harvest. It can promote the reproductive activity of certain soil microorganisms, thereby accelerating the decomposition of organic matter in the soil, increasing soil nutrients and improving soil fertility. At the same time, these microorganisms are beneficial to cereal crops but unfavorable to soybeans and sesame. If soybeans are planted after sesame or sesame is continuously cropped, the disease will be severe, especially in years with more rainfall, when the incidence of disease in sesame is even heavier, reaching about 50% in some years. Therefore, continuous cropping is avoided.

Although sesame is not strict about soil requirements, it requires a relatively dry environment in the late growth period and is most afraid of waterlogging. Therefore, flat land and sloping land with high, dry terrain and loose, fertile soil should be selected for planting. Sandy loam soil is best. Do not plant it in saline-alkali land, heavy clay land or low-lying, easily waterlogged land.

In order to reduce the harm of diseases and pests and maintain stable and high yields, sesame should be reasonably rotated with sorghum, corn or millet, preferably once every 3 years.

3.2 Fine land preparation and soil moisture conservation

Sesame is a dicotyledonous plant, and its seeds are small and weak in pushing through the soil, so it has relatively high requirements for land preparation. The plow layer is required to be loose on top and firm below, with fine, clean surface soil and good moisture conservation. Therefore, fine land preparation should be carried out before sowing, with plowing, harrowing and rolling done well to conserve moisture, stubble cleaned out, and clods broken up so that the soil is fine and crumbly. In particular, harrowing and rolling should be done promptly to conserve moisture at the freezing-thawing stage. Plots with irrigation conditions should be irrigated before sowing and moisture conserved.

3.3 Scientific fertilization

Scientific fertilization is an important measure to ensure high sesame yields. According to the current soil fertility status of our city, to obtain a yield of more than 100 kg per 667 sq m, generally 2500-3000 kg of high-quality farmyard manure and 10 kg of ternary compound fertilizer should be applied per 667 sq m. Sesame needs more fertilizer during the full flowering period, so it is appropriate to apply 10 kg of urea per 667 sq m at the bud stage or early flowering stage.

3.4 Selection of improved varieties and good seed treatment

The varieties currently promoted in production, such as Liaozhi No. 1, Liaozhi No. 2 and Batongbai, are high-yield and high-quality varieties at the present stage. Their growth period is 100-110 days, and they have wide adaptability, relatively strong lodging resistance and cold tolerance, and relatively high yields, generally about 150 kg per 667 sq m. Before sowing, a winnowing basket should be used to select seeds well to ensure that the seeds are plump.

In order to reduce the harm of diseases and pests, seeds should be disinfected before sowing. Seeds can be soaked for 1-2 hours in 0.2% carbendazim or 0.3% copper sulfate solution by seed weight, then washed clean with clear water, dried and sown. It is also possible to put the seeds in a small cloth bag 1 day before sowing, soak them in a prepared 0.5% copper sulfate solution, take the seeds out after 30 minutes, spread them flat in a dark place to dry in the shade, and then use them for sowing.

3.5 Timely sowing to ensure full stands

Sowing is an important part of sesame production. The habit of late sowing must be changed, and sowing should be done at the right time. When the temperature at a soil depth of 10 cm is stable above 12°C, sowing should be carried out. If sowing is too late, the plants will be tall and leggy, the capsules sparse, there will be many yellow tips, and the yield will be low. The results of sowing date trials indicate that sowing in early May is appropriate. Sesame is mostly sown in drills, with a seeding rate of 0.5-0.75 kg per 667 sq m and a soil covering thickness of 1-2 cm. Two to three days before sowing, moisten the manure with water. After opening the furrow, spread the manure first and then sow the seeds. After sowing the seeds, do not cover with soil; simply press twice in succession with a roller. If the soil moisture is poor at sowing, sow with water.

3.6 Reasonable dense planting

The varieties currently planted in production are mostly single-stem type varieties. The row spacing is appropriately 40-44 cm, with 12,000 plants retained per 667 sq m on flat land. On sloping land, retain 15,000 plants per 667 sq m. If a branching type variety is planted, the row spacing is 42-44 cm, with 10,000 plants retained per 667 sq m on flat land and 12,000 plants per 667 sq m on sloping land.

3.7 Strengthen field management

3.7.1 Breaking hard crust. Sesame often encounters rainfall after sowing and before emergence, and a hard crust forms on the ground, which is unfavorable for emergence. An iron rake should be used promptly to lightly break the hard crust. If drought and wind cause the surface soil to lose moisture after sowing, irrigation should also be carried out promptly and the hard crust broken.

3.7.2 Early thinning and early final thinning. In order to avoid crowding of seedlings and competition for water, fertilizer and light, early thinning and early final thinning should be carried out. Thin when the seedlings have one pair of true leaves, and final-thin when they have 2-3 pairs of true leaves. During final thinning, transplanting can be combined to fill gaps. Before transplanting, irrigate thoroughly so that the seedling root system combines closely with the soil, so as to transplant with soil. After digging holes and transplanting, water and cover with soil.

3.7.3 Hoeing and ridging management. In order to create a good environment of loose soil for sesame growth, hoeing should be carried out at the seedling stage, bud stage and flowering stage of sesame, and ridging and earthing up should be combined with topdressing. Three hoeings and two ridgings are required, with depth shallow, deep, shallow. After the rows close, stop hoeing and ridging. When large weeds are harmful, pull them out.

3.7.4 Irrigation. If drought occurs during the bud stage and flowering and capsule-setting stage of sesame, plant growth will be slow, flowers will drop, the number of capsules will decrease, empty seeds will increase, and the oil content will decrease. Therefore, irrigation should be carried out promptly. If flooding occurs in the late growth period, drainage should be carried out promptly.

3.7.5 Prevention and control of diseases and pests. First, weeds at the edges of sesame fields must be removed to eliminate overwintering hosts. In combination with spring land preparation, overwintering pests should be killed. To control larvae of the black cutworm older than the 3rd instar, manual killing should be carried out in the morning and evening. Use fully decomposed manure to reduce parasitism by insect eggs, and use light traps to kill adults.

For disease control in green agricultural product sesame, comprehensive control measures should be adopted. In addition to seed treatment before sowing, diseased plants found in the field should be promptly pulled out together with the roots and taken out of the field to be burned, so as to prevent the pathogen from spreading and infecting again.

When damping-off disease occurs at the seedling stage, hoeing and ridging management should be strengthened to raise soil temperature and reduce the harm. When bacterial wilt and leaf spot occur during the growth period, pesticides such as 75% chlorothalonil 600-fold solution, or 50% carbendazim 1000-fold solution, 70% thiophanate-methyl 500-800-fold solution, or 72.2% propamocarb aqueous solution at 60-100 ml per 667 sq m plus 30-50 L of water for spraying should be applied promptly for control.

3.7.6 Topping and flower termination. Sesame has an indeterminate inflorescence. In order to promote uniform maturity of sesame, increase grain weight, raise yield and facilitate harvest, topping and flower termination should be carried out around End of Heat. This can increase yield by about 10% compared with not topping and terminating flowers. The method of topping and flower termination is to pinch off about 1 cm of the stem tip of the sesame plant by hand.

3.7.7 Timely harvest. If sesame is harvested too late, the grains are likely to shatter, resulting in a high yield but not a good harvest. Therefore, it should be harvested promptly when 1-2 capsules on the lower part of the plant are about to split open.