Sesame planting technology and management

Sesame is an extremely high-quality oil crop and is widely used in refining sesame oil and other products. It has a short growth management cycle and is suitable for planting in spring, summer and autumn. Different varieties of sesame have different maturity periods: early-maturing varieties take about 3 months, mid-maturing varieties take about 3 and a half months, and late-maturing varieties take about 4 months of growth. Let’s learn about sesame planting techniques and management.

1. Choose the variety

When planting sesame in spring, since the period from sowing to harvesting is short, it is recommended to choose medium- and late-maturing varieties with a longer growth cycle , low temperature resistance, and taller plants. When planting in summer and autumn, considering that the growth cycle is also short, you should choose medium-early varieties that are heat-resistant and drought-resistant (especially when planting in autumn, you need to pay attention to preventing drought) and have shorter plants.

It is recommended to plant sesame varieties with high per-acre yield in areas with fertile soil, good water and fertilizer conditions, and high soil fertility levels. These varieties have a greater demand for fertilizers. On the contrary, in areas with poor soil, insufficient water and fertilizer conditions, and poor soil fertility, sesame varieties with lower per-acre yields should be selected, as these varieties require relatively less fertilizer.

For plots where field diseases and insect pests occur frequently, it is recommended to choose sesame varieties with strong disease and insect pest resistance. Alternatively, before sowing, the soil can be disinfected, sterilized and dewormed using fungicides and insecticides, or the seeds can be dipped in drugs to prevent the occurrence of pests and diseases.

2. Sowing time

The sowing time for spring sesame is usually from early April to the end of May. It is recommended to choose between the Grain Rain and Grain Full solar terms when the soil temperature rises to above 15 to 18 degrees Celsius, because sesame prefers a warm environment, and temperatures below 15 degrees Celsius are not conducive to germination and emergence.

Summer sesame is suitable for sowing from the end of May to the end of June, and it is recommended to sow around the Grain in Ear solar term, which is in early summer. The sowing time for autumn sesame is from mid-June to the end of July, but care should be taken not to sow later than the Beginning of Autumn, so as to avoid insufficient growth cycle and affect yield and grain maturity.

3. Sowing Depth

Since sesame seeds are small, they should not be sown too deep. The ideal sowing depth is about 2 cm. After sowing, cover the seeds with a thin layer of soil. The sowing depth should be controlled between 1.5 cm and 3 cm, avoiding being too deep or too shallow, so as not to affect the germination and emergence of seeds. When using the mulch covering method for planting, the seeds can be sown shallowly, with a depth of between 1.5 and 2 cm. For direct seeding in the open field or in areas with strong winds and sand, it is recommended to sow deeply, with a depth of between 2.5 and 3 cm.

4. Planting density and seed amount

The impact of season on sowing amount: For sesame sowing in spring, the recommended seed amount is about 0.4 kg per mu; for sowing in summer, it is about 0.3 to 0.4 kg; for sowing in autumn, it is recommended to increase to 0.4 to 0.5 kg to adapt to the shorter growing season.

The influence of sowing method on sowing amount: broadcast sowing method uses the largest amount of seeds, and 0.4 to 0.5 kg per mu is recommended. The row sowing method is in the middle, with the recommended amount being 0.35 to 0.45 kg per mu; the hole sowing (spot sowing) method uses the least amount of seeds, with the recommended amount being 0.3 to 0.35 kg per mu.

Plantings in the North and Northwest regions may be slightly greater than in the South. Single-stem tall upright varieties should be sown densely to increase the number of flowers and pods and the yield per mu. Varieties with many branches and low plants should be planted sparsely to ensure sufficient growing space.

The impact of plant type on planting density: For low-branched sesame varieties, the recommended plant spacing is about 22 cm and the row spacing is about 33 cm, ensuring 8,000 to 9,000 seedlings per acre. For straight and tall single-stem sesame varieties, the recommended plant spacing is about 14 cm and the row spacing is about 25 cm, ensuring 10,000 to 12,000 seedlings per acre.

5. Sowing Method

Because sesame seeds are tiny, direct sowing may be difficult to control density. It is recommended to mix the seeds evenly with a small amount of wood ash or fine dry soil first to facilitate sowing. Sesame sowing requires appropriate soil moisture. If the soil moisture is insufficient, water it 2 to 3 days in advance to create moisture, then loosen the soil and sow. Avoid watering immediately after sowing to prevent the seeds from being washed away. It is effective to loosen the soil and sow seeds after a light rain, or to remove the stubble and loosen the soil in time after the previous crop is harvested and sow seeds while the soil is moist.

Whether broadcasting or drilling, ensure that the seeds are sown evenly and covered with a thin layer of soil to promote rapid emergence. For hole sowing and row sowing, it is recommended to keep the row spacing at 30 to 40 cm and the plant spacing at 20 to 25 cm to avoid over-dense sowing and affect later yields.

Considering that sesame has shallow roots and is afraid of waterlogging and cannot tolerate waterlogging, it is recommended to sow in ridges and furrows. The ridge height is about 20 cm, the furrow width is about 30 cm, and the furrow width is 1.2 to 1.5 meters. A multi-row planting pattern is adopted on the sowing beds.

6. Field management after sesame seedlings emerge

After sesame seedlings emerge, thinning should be carried out in time, usually in 2 to 3 times, until the final seedlings are determined. For example, if thinning is done twice, the first time should be done when the sesame has 2 to 3 true leaves, and the second time should be done when 4 to 5 true leaves are grown to complete the thinning and transplanting.

Before germination, if the topsoil is found to be compacted, the soil should be loosened immediately to eliminate the compaction and create conditions for the seeds to germinate and emerge smoothly. After germination, keep the soil moist to promote rapid growth of seedlings. In the entire seedling management, the strategy of "moisturizing in the early stage to promote seedling growth, and appropriate water control in the later stage to promote root development and plant health" should be adopted.

It is recommended to carry out 3 to 4 inter-tillages from the emergence of sesame seeds to the closure of ridges in order to achieve three main purposes: to increase the looseness of the soil and its ability to retain water, moisture and fertilizer. Promote the rapid formation of developed root systems in seedlings and form strong seedlings. Remove weeds to ensure that the sesame seedlings have adequate resources for growth.

It is recommended to carry out the first inter-tillage when the sesame has grown 2 to 3 leaves. It can be combined with the first thinning. Just shallowly scratch the ground to break up the hard soil on the surface. The second tillage is carried out when the sesame has grown 5 to 6 leaves. The tillage depth should be controlled at 3 to 5 cm to avoid damaging the roots of the seedlings. The third tillage is carried out when the sesame has 8 to 10 leaves, and the depth is controlled at 6 to 8 cm. The fourth intertillage is carried out before ridge closing or before the initial flowering period. Deep tillage can be combined with the application of pre-flowering fertilizer, and attention should be paid to soil cultivation to improve the ability to prevent drought and flood.

Management after intertillage: After sesame is planted in ridges, especially after it blooms in large quantities, intertillage should be stopped to avoid damaging the roots and flowers.

7. Fertilization management

Base fertilizer before sowing: Sesame has a short growing period, usually only 85 to 90 days for early-maturing varieties, so sufficient base fertilizer is the key to ensuring high yields. Base fertilizer should be applied together with land preparation, mainly organic fertilizer or well-rotted farmyard manure, with appropriate amounts of nitrogen, phosphorus and potassium fertilizers, especially phosphorus fertilizer. For plots where the soil is deficient or has a lot of pests and diseases, you can add appropriate amounts of micro-fertilizers and bacterial fertilizers. It is generally recommended to apply 200 to 400 kg of commercial organic fertilizer or more than 2,500 kg of decomposed farmyard manure, as well as 30 to 40 kg of nitrogen, phosphorus and potassium compound fertilizer or corresponding phosphate fertilizer, urea and potassium sulfate per mu. Adjust the amount of fertilizer in time according to soil fertility and planting varieties.

Top dressing during the growth period: Top dressing of sesame should target its key growth stages, including the 5 to 6 leaf stage (seedling stage), the budding to early flowering stage (flower bud differentiation stage) and after the peak flowering stage (flowering and pod setting stage). Top dressing during the seedling stage aims to promote the growth of seedlings. If the base fertilizer is sufficient and the seedlings grow well, no additional top dressing is required; if the growth is slow, urea can be applied in appropriate amounts. The focus of topdressing from budding to early flowering period is to support flower bud differentiation. Nitrogen fertilizer should be used as the main fertilizer, supplemented by phosphorus and potassium fertilizers. Urea, potassium sulfate or medium- and high-nitrogen compound fertilizers can be applied, and potassium dihydrogen phosphate and boron-containing foliar fertilizers can be sprayed. After the peak flowering period, topdressing should be mainly potassium fertilizer, supplemented by phosphorus and nitrogen fertilizers, with the focus on promoting flowering and pod setting. High-potassium compound fertilizer, potassium sulfate and urea can be applied, and combined with potassium dihydrogen phosphate and boron and calcium-containing foliar fertilizers for spraying.

8. Watering management

Soil moisture before sowing: Sesame sowing requires ensuring that the soil has appropriate moisture. Dry or insufficiently humid soil should be watered 2 to 3 days in advance to increase moisture, while soil that is too humid should wait for the water to penetrate before sowing. The ideal soil moisture level at planting time is about 80%.

Humidity control during the germination period: The suitable humidity from sesame sowing to germination is about 75%. Too low or too high humidity is not conducive to the normal germination and emergence of seeds. If the soil moisture is adequate before planting, additional watering during this period is usually not necessary.

Water requirement after emergence: From the emergence of sesame seedlings to the budding and flowering, the suitable soil moisture is about 70%. From flowering to the capping of the plant, the humidity can be adjusted to 75-80%. From capping to maturity and harvesting, it is more appropriate to maintain a humidity of about 70%.

Water management during growth: During the entire growth cycle of sesame, keeping the soil continuously moist during the germination and emergence period will help ensure uniform emergence. Proper water control from the seedling stage to before budding helps root development and plant health.

The flowering and podding stage is the period when sesame has the greatest demand for water, and sufficient water supply must be ensured. When watering, you should use small amounts of water frequently to avoid flooding with large amounts of water, so as to prevent water accumulation in the field, which may lead to waterlogging of the roots, causing flowers and pods to fall or reduced yields.

9. Topping at the right time

The best time to top sesame is within 15 to 30 days after about 70% of the plants in the field have bloomed. The specific time depends on the different growth cycles of spring sesame, summer sesame and autumn sesame. In addition, when sesame enters the late flowering stage, the top leaves are clustered and the new shoots stop growing, it also indicates that the time for topping has arrived. When topping, cut off the top 2 to 4 cm of the main stem and branches.

The topping length should be flexibly adjusted according to the topping time, generally 2 to 3 cm. Plants that are toppled early can be shortened to 1 to 2 cm, while those that are toppled late can be extended to 4 to 5 cm. Be careful to avoid topping too early or too late, so as not to affect the amount of flowering and pod setting or the topping effect.

Topping should be completed at one time, from top to bottom, from main stem to branches. At the same time, remove side branches without flowers and pods, but avoid damaging the flowers and leaves, especially the green leaves in the flowering and pod-forming areas. It is recommended to topping the plants in the morning on a sunny day and avoid rainy weather to reduce the risk of infection by pathogens and pests.

After topping, top dressing and watering should be applied in time to meet the nutritional needs of new sesame shoots and prevent premature aging and yield reduction. After the new side branches grow 4 to 6 leaves, spray chlormequat or chlormequat chloride with potassium dihydrogen phosphate 1 to 2 times to promote flowering and pod setting and prevent lodging.

10. Pest and disease control

During the growth period, sesame is susceptible to diseases such as verticillium wilt, wilt, stem blight, and blight, as well as pests such as aphids, thrips, borers, moths, cutworms, grubs, and bollworms. Farmers should take timely measures to prevent and control field pests and diseases based on their occurrence.

11. Harvest time

Sesame should be harvested promptly after it matures. Harvesting too early will result in incomplete seed development, and reduced yield and quality. If harvesting is too late, the pods may dry out and burst, resulting in grain loss and reduced yield.

Most of the leaves on the sesame plant turn yellow and fall off, leaving only a few green leaves on the top. The 2-3 fruit pods at the bottom of the plant are slightly cracked, the middle pods are swollen and hardened, and the upper pods are full and filled with juice.

If it is difficult to judge by observation, you can refer to the following time: spring sesame is harvested in mid-to-late August, summer sesame is harvested in mid-to-early September, autumn sesame is harvested at the end of September, or it can be harvested 20-25 days after the flowers have withered and the topping has been completed.

Flexible judgment of the harvest period: The maturity period of sesame is affected by the conditions of the plot and the management methods. For example, plots with sparse planting mature earlier than those with dense planting, and plots with less water and fertilizer management in the middle and late stages mature earlier than those with sufficient water and fertilizer. Farmers need to flexibly judge the best harvesting time based on the actual growth conditions of sesame.

The above is an introduction to sesame planting techniques and management key points. It is not easy to achieve high yields in sesame planting. You can study the reference content based on actual conditions.