How to Grow Sesame? A Detailed Guide to Key Cultivation Techniques
Sesame, also known as zhim or huma, is the seed of the huma plant, an annual erect herbaceous plant, 60-150 cm tall. It is found throughout the world's tropical regions and some temperate regions. Sesame is one of China's main oil crops and has high application value. Its seeds have an oil content of up to 55%. Since ancient times, China has been famous throughout the world for the many kinds of foods and delicious dishes made with sesame and sesame oil.
I. Land Preparation and Bed Making:
Whether it is summer sesame or autumn sesame, sowing takes place in seasons with high temperatures and high evaporation, so fine land preparation and preserving soil moisture are the keys to full emergence. When there is plenty of soil moisture, after plowing, harrow the land finely in both directions, and after sowing, harrow to cover the seed. When there is little soil moisture, sow immediately after harrowing, harrow to cover the seed, and press the soil to conserve moisture. Sesame is afraid of waterlogging, and its growth period falls during a time of relatively abundant rain, so when sesame is grown alone, beds should be made——about 2-3 m wide, with well-opened bed furrows, waist furrows and surrounding furrows for timely drainage and irrigation.
II. Timely Sowing
1. Sowing time: The suitable sowing period for summer sesame is late May to early June. The suitable sowing period for autumn sesame is early to mid-July, and where heat conditions are good it can be delayed until late July.
2. Seed rate per mu: 400 g for broadcasting, 350 g for drilling, and 250 g for dibbling. On fields with high soil fertility, few pests and diseases, and high water content, the sowing rate can be appropriately reduced.
3. Sowing methods: There are three sowing methods for sesame: dibbling, broadcasting and drilling. Broadcasting is the traditional sowing method in the Jianghuai region and is suitable for sowing to catch soil moisture. When broadcasting, the seeds are evenly scattered, the soil cover is shallow, and seedlings emerge quickly, but it is not conducive to field management. Drilling can control row and plant spacing, allows rational close planting and facilitates field management such as thinning and intertillage, and is suitable for mechanized operation. For dibbling, 5-7 seeds per hole. Regardless of the sowing method, shallow and even sowing with a depth of 2-3 cm is appropriate.
III. Field Management
1. Chemical weed control: 3 days after sowing, use 60 ml of 60% Henais emulsifiable concentrate per mu, add 50 kg of water to dilute, and spray evenly on the bed surface; this can reduce weed growth.
2. Timely thinning: After more than ten days, when 2-3 cotyledons have grown, thin the seedlings, and thin again after 5-6 days, so that the plant spacing is 22-24 cm, with 8000-10000 plants per mu. Suitable plant spacing is beneficial for branching.
3. Removing the terminal bud: After the full fruiting stage, when the leaf nodes at the top of the main stem cluster and growth nearly stops, choose a sunny morning to remove the terminal bud. The topping method is very simple: pinch off the apical growing point within about 1 cm, but topping is limited only to the apical growing point, not a long section at the top. Pinching too much will reduce the number of capsules per plant and lead to reduced yield.
4. Irrigation and drainage: Sesame is most sensitive to soil moisture; it fears waterlogging and cannot tolerate long-term drought, so attention must be paid to irrigation and drainage.
IV. Rational Fertilization
1. Early application of seedling fertilizer: Because sesame seeds are relatively small, and because excessive nitrogen fertilizer is often applied as a base fertilizer, the seedlings are prone to excessive growth and form leggy seedlings. Therefore, for sesame, in combination with early thinning and early final thinning, apply a seedling fertilizer based mainly on quick-acting fertilizer early according to seedling condition. Applying seedling fertilizer well is an important measure for early development and healthy growth of sesame. For seedling-stage fertilizer, diluted decomposed human excrement and urine or urea is preferable. Generally, after final thinning, apply 2-3 kg of urea per mu as a topdressing. When drought is severe, first relieve the drought and then topdress, or dilute with thin human excrement and urine and pour it on. For those with poorer seedling vigor, the method of “opening a special meal” should also be adopted, applying a seedling-promoting fertilizer. When topdressing seedling fertilizer to sesame, because sesame roots are relatively shallow, it should be applied as shallowly as possible or mainly around the roots.
2. Skillful application of bud fertilizer: The sesame budding stage is exactly when flower bud differentiation begins, and at this time vegetative growth and reproductive growth of the plant are both vigorous. Therefore, applying bud fertilizer well plays a decisive role in high sesame yield. Bud-stage fertilizer is generally based mainly on nitrogen fertilizer, supplemented by phosphorus and potassium fertilizers. Per hectare, 75-150 kg of urea can be applied respectively, plus 150-225 kg of phosphate fertilizer and 75-150 kg of potassium fertilizer. When fertilizing, for drilled sesame, open furrows about 10 cm from the sesame plants and apply in bands or in spots, applying into a 10 cm deep soil layer to facilitate root absorption, then cover with soil after application. For broadcast sesame, decomposed cake fertilizer or granular urea can be mixed thoroughly into finely crushed soil and broadcast evenly, and immediately after fertilization, carry out intertillage and loosening of the soil to cover the fertilizer. In dry weather, after application, spray water to give full play to the fertilizer effect. A pouring method can also be used, that is, use 4-6 kg of urea per mu mixed with 200 kg of water and pour it over the base of the sesame plants. In addition, in boron-deficient areas and boron-deficient soils, boron fertilizer should also be increased as appropriate.
3. Heavy application of flower fertilizer: Sesame grows fastest when it enters the flowering stage, and the nutrients absorbed during this period account for 70%-80% of the whole growth period. In order to meet the needs of plant growth and development, spraying potassium dihydrogen phosphate 1-2 times can delay leaf senescence, make sesame grow vigorously, accumulate more photosynthetic products, increase the number of flowers and capsules, maintain stable late growth without premature senescence, and make the grains plump. At the same time, during the flower and pod stage, lateral roots have begun to form in large numbers, the absorptive capacity of the root system is enhanced, the growth rate of the plant accelerates, and the demand for nutrients also increases significantly. Therefore, a heavy application of flower and pod fertilizer is needed. Branching varieties are generally fertilized when branches appear, and single-stem varieties are fertilized from budding to early flowering. For foliar fertilization, 0.4% potassium dihydrogen phosphate is generally used. Generally, 5-8 kg of urea per mu mixed with 200 kg of water is poured over the base of the sesame plants, and composted cake fertilizer, human excrement fertilizer, etc. can also be applied. In addition, from early flowering to full flowering, foliar topdressing can be carried out by choosing a sunny afternoon and spraying a 0.3% potassium dihydrogen phosphate solution on both sides of the leaves, with an interval of 5-6 days each time, for 2-3 consecutive sprays.