In this article we will discuss about:- 1. Origin and Distribution of Sesame 2. Area and Production of Sesame 3. Climate, Soils and Tillage 4. Varieties and Seasons 5. Seeds and Seeding 6. Nutrient Management 7. Cropping Systems 8. Water Management 9. Weed Management 10. Harvesting and Threshing 11. Quality Considerations.
Contents:
- Origin and Distribution of Sesame
- Area and Production of Sesame
- Climate, Soils and Tillage of Sesame
- Varieties and Seasons of Sesame
- Seeds and Seeding of Sesame
- Nutrient Management for Sesame
- Cropping Systems of Sesame
- Water Management for Sesame
- Weed Management for Sesame
- Harvesting and Threshing of Sesame
- Quality Considerations of Sesame
1. Origin and Distribution of Sesame:
The greatest weight of evidence indicates the Ethiopian area as the origin of cultivated sesame, although there is considerable argument in favour of Afghanistan, with subsidiary centers in Indo- Malaya and China.
Its cultivation in India is ancient but De Candolle (1890) was of the opinion, now known to be based on inaccurate data, that the plant was introduced to India from Indonesia prior to the Aryan invasion. Bedigian and Hartin (1986) indicated that sesame originated in the Indian subcontinent and spread through west Asia to India, China and Japan, which latter became secondary centers of origin.
Major sesame producing countries are India, China, Myanmar, Sudan, Pakistan, Mexico, Ethiopia, Sri Lanka and Burma. In India, major sesame cultivating states are Gujarat, Rajasthan, Madhya Pradesh, Uttar Pradesh, Tamil Nadu and Maharashtra.
Sesame, sesamum or gingelly (Sesamum indium) known as til (Hindi) and nuvvulu (Telugu), is the most ancient oilseed crop known and used by man, so ancient that it is almost impossible to say with any degree of accuracy where and when domestication took place.
It has earned a poetic label Queen of Oilseeds due to high quality polyunsaturated stable fatty acid, which restrains oxidative rancidity. It is most ancient oilseed crop of India next to groundnut and brassica oilseeds.
2. Area and Production of Sesame:
Globally, sesame is cultivated (2003) over an area of 6.57 M ha with an annual production around 2.94 M t. World average productivity is 448 kg ha-1. India ranks first both in the area (35%) and production of sesame (25%) in the world. However, its productivity in India is 370 kg ha-1.
In India, as per 2009-10 statistics, sesame is cultivated in an area of 1.94 M ha with a production of 0.66 M t accounting to a productivity of 0.30 t ha-1. Largest area (0.59 M ha) under sesame is in Rajasthan followed by UP (0.33 M ha). Production is highest in WB (0.19 M t) followed by Rajasthan (0.10 M t). Highest yield (0.82 t ha-1) is in WB followed by Assam (0.56 t ha-1).
3. Climate, Soils and Tillage of Sesame:
Sesame is considered to be basically a crop of warm regions of tropics and subtropics but its extension into more temperate zones is made possible by breeding suitable varieties.
Its main distribution is between 25°S and 25°N but found growing up to 40°N in China, Russia and USA and 30°S in Australia and 35°S in South America. Its altitude range is normally below 1,250 m, although some varieties may be locally adapted up to 1,500 m. It is grown in Himalayas up to 1,250 m and up to 2,000 m in Nepal.
Temperature:
Sesame requires fairly hot conditions during growth for optimum yield. A temperature of 25° to 27°C is ideal for rapid germination, initial growth and flower formation. Germination is delayed at temperatures below 20°C and temperature less than 18°C after emergence will severely retard growth.
Low temperatures at flowering results in pollen sterility and premature flower drop. Conversely, temperatures above 40° C at flowering seriously affect fertilisation and the number of capsules set will be low.
Day Length:
Sesame is basically a short day plant but many varieties have become locally adapted to various light periods. However, when these varieties are introduced into other areas with similar day length but dissimilar rainfall or temperature, there is considerable variation in growth and yield from that in their original home.
In India, sesame is grown in kharif and rabi. Even in the same district, two distinct verities, each with its own characteristics must be grown. The kharif variety will produce uneconomic yields in the rabi and vice versa. Sown in June, when there is approximately a day length of 13.5 hrs were found with insufficiently filled ovaries leading to few fully developed fruits.
Such varieties when sown in August when there is a day length of 12.5 hrs produced normal ovaries. The substantial difference in growth and development due to varying photoperiods on short and long season types in India emphasises necessity for selecting the most suitable variety for a seasonal planting.
Rainfall:
Once established, sesame is capable of withstanding a higher degree of water stress (drought) than many other crops. The seedling stage, however, is susceptible to moisture shortage. The crop can be grown entirely on stored soil moisture and only an odd shower early in growth can produce good yields. A rainfall of 600-1,000 mm can result in optimum yield under varying soil and climatic conditions in India.
Sesame is extremely susceptible to waterlogging and heavy continuous rains at any time during the growth will greatly increase the incidence of fungal diseases. Heavy rains at flowering will drastically reduce the yields and if cloudy weather persists for any period at this time, yield will be drastically reduced.
Soils:
Sesame grows well on a variety of soils but thrives best on those, which are moderately fertile with good internal drainage. Soils with neutral reaction are preferred. It will grow well on soils with a pH ranging of 5.5 to 8.
In Uttar Pradesh and Madhya Pradesh, sesame is grown on lateritic soils, light in texture and poor in fertility and on more heavy soils. In Gujarat, it is grown on sandy loams and in Karnataka on red earths. It is grown on clay loams in Andhra Pradesh and loams in Tamil Nadu. In Maharashtra, sesame is grown on medium to heavy black soils.
Tillage:
Land preparation for sesame is similar to as that for wheat, sorghum and other millets. For kharif crop, land is deep ploughed with summer showers in April-May. With the onset of monsoon rains two to three harrowings are given to break up the clouds. Heavier soils require only 3 or 4 harrowings to produce a fine seedbed.
Rabi crop requires less land preparation, as the soils are frequently moist from monsoon rains. Stand establishment is a problem if sesame has to be grown after kharif rice. Under such conditions, there is scope only for minimum tillage.
4. Varieties and Seasons of Sesame:
Varieties:
Late season varieties are short day plants and when grown under long days become excessively vegetative. Early cultivars are day neutral. Short photoperiod may increase the number of capsules per plant in early and mid-late cultivars. Therefore, varieties recommended are season and location specific. Some of the recommended varieties are given in Table 11.1.
Seasons:
In India, sesame is growing during kharif, semi rabi, rabi and summer or more than one season in southern parts. Optimum sowing seasons are given in Table 11.2.
5. Seeds and Seeding of Sesame:
Seed Rate:
The seed rate for sesame depends on the variety, method of seeding and season. It varies from 5 to 7 kg ha-1 for broadcasting to around 3 kg ha-1 for row seeding. For mixed/intercropping it is usually less than one kg ha-1. For broadcasting, recommended seed rate is 6 and 5 kg ha-1 under rainfed and irrigated conditions, respectively. For row seeding, recommended seed rates are 5 and 4 kg ha-1 under rainfed and irrigated conditions.
Spacing:
Spacing between rows and within the row depends on variety, season and management practices. It varies from 30 x 10 to 45 x 15 cm under different situations.
Recommended spacing for different states in different seasons are given below:
Method of Seeding:
Sesame is usually sown by broadcasting in most situations. However, row seeding with seed drills leads to higher yield due to optimum stand establishment and intercultivation with blade harrows for weed control. Optimum seeding depth is 3 to 4 cm.
For uniform seed distribution of seed over the field, it is mixed either with sand or well powered FYM both for drilling and broadcasting. Seed treatment with Thiram (3 g kg-1) is effective against seed born diseases. For minimising bacterial leaf spot, the seed may be soaked in 0.025 per cent solution of Agrimydn-100 for 30 minutes prior to seeding.
6. Nutrient Management for Sesame:
In India, sesame is cultivated by poor fanners on relatively poor soils with no manure, reflecting in very low average yield. It is likely that this crop is less likely to receive fertilisers than many other tropical crops. This is due to weak financial status of the farmers but not to any inability of the plant to respond to added fertilisers. Direct application of manures and fertilisers to sesame crop is rare, with the result that relatively little work has been carried out on its nutrient requirements.
Nutrient Uptake:
Sesame crop yielding 10 t ha-1 dry matter containing 2.2 t ha-1 of seed remove 120 N, 32 P2O5 and 136 K2O kg ha-1. Hence, the crop responds to added fertilisers both under rainfed and irrigated conditions. Deficiency symptoms are excepted when the leaves of plants contain less than 2 per cent nitrogen, 0.2 per cent calcium and 0.15 per cent magnesium with an yield around 500 kg ha-1.
NPK Requirement:
In India, sesame responded to applied nitrogen and phosphorus. However, the degree of response to these nutrients depends upon the total rainfall and its distribution during the crop season. Response to nitrogen is up to 60 kg ha-1. Split application of nitrogen, half at seeding and the remaining around 35 DAS is ideal. Placement of nitrogen improves the yield over broadcasting.
Response of sesame to phosphorus depends on the rate of nitrogen application. Depending on the level of soil phosphorus, 15-30 kg P2O5 ha-1 seems to be adequate under most situations. Soils deficient in potassium responds to around 20 kg K2O ha-1. Placement of fertiliser at seeding using seed drills is more effective than broadcast application. Recommended fertiliser schedule for sesame is given in Table 11.3.
Wherever specific recommendation has not been made, half of the recommended nitrogen and full dose of phosphorus and potassium must be applied at seeding and the remaining nitrogen 35-40 DAS, provided soil moisture or irrigation is adequate.
Sesame responds to about 50 kg S ha-1 if the soils are deficient in sulphur. Integrated nutrient management consisting of 5 t ha-1 of FYM, 40 kg nitrogen, 20 kg phosphorus and seed treatment with Azospirillum has given encouraging results at several situations.
7. Cropping Systems of Sesame:
Sequence Cropping:
Sesame, by virtue of its short duration, fits well into a number of intensive systems either as catch crop or sequence crop.
Some of the sequences cropping systems are given below:
Intercropping:
Yield and monetary advantage from sesame are higher when it is cultivated as a sole crop than as mixed/ intercrop. However, sesame is grown as mixed/intercrop, keeping in view the risk of total crop failure under abnormal rainfall conditions.
Some of the intercropping systems involving sesame are given below:
8. Water Management for Sesame:
Except when cultivated during rabi/summer, sesame receives any irrigation. Nevertheless, protective irrigation will greatly benefit the rainfed crop whenever there are prolonged dry spells, especially on light soils. Yield advantage up to 200 per cent due to supplemental irrigation has been reported.
Critical Stages for Irrigation:
For rabi/summer sesame, a presowing irrigation is necessary for optimum seed generation and adequate stand establishment, provided soil moisture is inadequate at the time of seeding. Flower initiation and capsule filling stages are most sensitive to water deficits.
Scheduling Irrigation:
Scheduling irrigations at 50 per cent DASM is adequate. If irrigations are scheduled based on IW/CPE ratio, a ratio of 0.6 is optimum under most situations. Depending on soil type, weather conditions and crop duration, irrigations maybe given once in 12 to 15 days.
If irrigation water is not a limiting factor, flower initiation, maximum flowering and capsule filling results in optimum seed yield. Depending on the duration, sesame water requirement ranges between 350 and 450 mm. The crop is usually irrigated by check basin method of irrigation.
9. Weed Management for Sesame:
Cultural Management:
Sesame is sensitive to weed competition during the first 15-35 DAS. A minimum of two weedings, one after 15 DAS and another 35 DAS are required to keep the field relatively weed free. Row seeded crop facilitates use of blade harrows for intercultivation. Two intercultivations, 15 and 35 DAS followed by one hand weeding keeps the field free of weeds.
Use of Herbicides:
Herbicides use, especially under rainfed conditions, is very limited due to low yield, which may not compensate for the cost of herbicides. If necessary, Alachlor (1.0) or Thiobencarb (2.0) can be used as PRE spray for effective control of weeds. Use of PRE herbicides followed by on hand weeding around 30 DAS is the most appropriate way of weed management in sesame.
10. Harvesting and Threshing of Sesame:
Harvesting:
Depending on the variety, sesame crop takes 80-150 days for maturity. The crop is harvested when the leaves, stems and capsules begin to turn yellow and the lower leaves start shedding. To prevent shedding of seed, the crop should not become dead ripe in the field. The ripe plants are cut at the ground level carried to threshing yard, stacked for a week in the sun with the cut ends upwards.
Threshing:
During the sun drying process, the capsules crack open with dried seeds falling on the threshing floor. The seed still remaining in the capsules can be easily removed by shaking the dried stems. In case some of the seed is still remaining within the capsules, it can be removed by beating with wooden sticks. Winnowing and cleaning is carried out following the common procedures. The cleaned seed is stored with seed moisture content not more than 8 per cent.
Average grain yield under rainfed conditions, as sole crop, rage between 200 and 400 kg ha-1. Irrigated summer sesame can yield up to 600 kg ha-1. There are instances of harvesting yields up to 800 kg ha-1 under rainfed conditions with good management practices. Under irrigated conditions yields up to 1500 kg ha-1 are not uncommon. A well-managed commercial sesame crop has yielded around 3.0 t ha-1 in South America.
11. Quality Considerations of Sesame:
Sesame is the oldest oilseed crop of the world. The seed has high food value because of its higher contents of good quality edible oil and nutritious protein.
Seed Composition:
Sesame seed protein content varies from 20 to 28 per cent with an oil content ranging between 48 and 55 per cent. Its mineral content is around 6 per cent.
Among oilseeds proteins, sesame seed proteins are more nutritious in that it is rich in methionine and tryptophane. Like other oilseeds, it is also deficient in lysine. The other limiting amino acids are thionine, isoleucin and valine. Sesame seed contains 21-25 per cent carbohydrates, 1.0 per cent calcium and 0.7 per cent phosphorus.
Sesame oil has two constituents namely sesamin and sesamol. They are responsible for very high stability of oil at room temperature and frying tempetrues. The sesamin content ranges from 0.07 to 0.6 per cent.
Utilisation:
Sesame oil has high quality and is used as a substitute for olive oil in salads, pickles and in cooking. The oil is also used in the manufacture of margarine and poorer grades are used in manufacture of paints and soaps and as lubricant and illuminant. Fried seeds are cooked into soups. Sesame oil is used as a solvent or carrier for many medicines and cosmetics.
Sesame cake rich in protein (30 to 50 per cent) is also rich in sulphur containing amino acids. Nutritious food products can be made from sesame cake. An infant food and nutritious beverage can be made using 70 per cent soya protein and 30 per cent sesame protein.