Under the names rapeseed and mustard, several oilseeds belonging to the crucieferae are grown in India.
- Brown mustard, commonly called rai (raya or laha)--Brassica juncea (L.) Czern. & Coss
- Yellow sarson--B. campestris L. var. sarson Prain
- Brown sarson--B. campestris L. var. dichotoma Watt
- Toria (lahi or Maghi Labi)--B. campestris L. var. toria Duth.
- Taramira or tara (eruca sativa Mill.)
In trade, sarson, toria and Taramira are known as rapeseed, and rai as mustard.
Banarsi rai (B. nigra Koch.) which does not fall under any of the four groups is a garden crop used as spice. The cultivation of white mustard (Brassica alba syn. Sinapis alba) is no longer found in India. Rai and Yellow sarson are self-fertile and the rest of the cruciferous oilseeds, viz. brown sarson, toria, taramira, Banarasi rai and white mustard, are self-incompatible.
The acreage under yellow sarson is scantily (mainly in Bihar) and constantly on the decrease. In the recent past, the accreage under brown mustard is steadily on the increase (over 65%) at the expense of other Brassica due to its higher production, greater to pests and diseases and moisture stress.
ORIGIN. Brassica juncea L. (rai) was originally introduced from China into north-eastern India. From where it has extended into Afghanistan via the Punjab. Eastern Afghanistan, together with the adjoining north-western India is one of the independent centres of brown sarson (Brassica campestris var. brown sarson). Yellow sarson (B. campestris var. yellow sarson) is commonly grown in the eastern parts of India where it shows much diversity of forms. Taramira is a relatively recent introduction into India. It is believed to be a native of southern Europe and North Africa.
ECONOMIC IMPORTANCE. Rapeseed and mustard yield the most important edible oil content of the seeds of different ranges from 30 to 48 per cent. In the case of white mustard, the oil content ranges from 25 to 33 per cent. The oil obtained is the main cooking medium in Northern India and can not be replaced by any other edible oil. The seed and oil are used as a condiment in the preparation of pickles and for flavouring curries and vegetables. The oilcake is mostly used as cattle feed. The leaves of young plants are used as a green vegetable. The use of mustard oil for industrial purposes is rather limited on account of its high cost.
BOTANICAL DESCRIPTION. Rapseeed and mustard include annual herbs ranging in height from 0.45 to 1.75 m. Roots, in general, are long and tapering. Toria is more or less a surface-feeder and brown sarson has long roots, with a limited lateral spread, enabling its successful cultivation under drier conditions. Yellow sarson has both extensive and lateral spread. The height of the stem varies from 45 cm (in some varieties of toria) to 1.75 m (in yellow sarson). In toria and brown sarson, the branches arise at an angle of 30 0 to 400.In yellow sarson, branches arise laterally at an angle about 10 0 to 200 and give the plant a narrow and pyramidal shape. The inflorence is coroymbose raceme. In the case of sarson the four petals are spread apart, whereas in brown sarson and toria the petals overlap or may be placed apart, depending upon the variety. The flowers bear a hypogynous syncarpous ovary. In brown sarson and toria, the ovary is bicarpellary, whereas in the case of yellow sarson, it may also be tri or tetra-carpellary.
The fruit is a siliqua. The pods are two-valved, three-valved or four-valved, depending upon the number of carpels in the ovary. The flowers begin to open from 8 a.m. and continue up to 12 noon.
DISTRIBUTION, AREA AND PRODUCTION. The crop is grown both in subtropical and tropical countries. In Asia, it is chiefly grown in China, India and Pakistan. It is also grown in Europe, Canada and the USSR, but the forms of rapeseed and mustard grown there are different from those grown in India.
India occupies the first position, both with regard to acreage and production of rapeseed and mustard in the world. In India the Braddica crops occupy the second largest position after groundnut, with 3-5 million hectares, producing about 2 million tonnes of seed annually. The chief states producing them are Uttar Pradesh, Punjab, Haryana, Assam, Bihar, Madhya Pradesh, Rajasthan, West Bengal and Orissa.
CLIMATE AND SOIL. The rapeseed and mustard crops are of the tropical as well as of the temperate zones and require relatively cool temperatures for satisfactory growth. In India, they are grown in the rabi season from September-October to February-March. The rapeseed and mustard crops grow well in areas having 25 to 40 cm of rainfall. Sarson and toria are preferred in low-rainfall areas, whereas raya and toria are grown in medium and high-rainfall areas respectively.
The rapesed and mustard thrive best in light to heavy loams. Raya may be grown on all types of soil, but toria does best in loam to heavy loam. Sarson is suited to light-loam soil and taramira is mostly grown on very light soils.
CULTIVATION. A fine seed-bed is required to ensure good germination. In irrigated areas, the first ploughing is done with a medium sized soil-turning plough, followed by two to four ploughing with a desi plough or a cultivator. Sohaga (Planking)
is given after every ploughing.
In rainfed areas, one to two ploughings with a desi plough or a cultivator, each followed by planking, may be given. Toria, in particular, requires a fairly moist seed-bed for good germination, but excessive moisture should be avoided. The rate in the case of mixed cropping depends on the proportion of the rapeseed to the main crop.
When sown pure, 5 kg of seed per ha is used for all rapeseeds and mustard. When sown mixed with other crops, the time of sowing rapeseed and mustard is governed by the sowing of the main crop. The first half of September is best for sowing toria (if wheat is to follow, it should be sown by the end of August), 25th September to 15th October for sarson, 30thSeptember to 15th October for raya, and tarantira is sown throughout October. The seed from healthy and desirable plants, grown in isolation in the case of self-sterile form, should be used. Whenever moisture in the field is inadequate, the seed is mixed with moist soil and kept overnight. For distributing evenly, the seed is usually mixed with sand before sowing.
In mixed cropping rapeseed and mustard are sown in rows 1.8 to 2.4 metres apart across the main crop. The pure crop of rapeseed or mustard is sown at a depth of 4 to 5 cm in lines, 30 cm apart, with a drill, or with a (tube) attached to the plough. Thinning is done three weeks after sowing to maintain a plant-to-plant distance of 10 to 15 cm.
One hoeing in the case of toria in the third week after sowing and 1-2 hoeings in the case of sarson and raya are adequate. Forty kg of W per ha is optimum for all rapeseed and mustard crops in rainfed areas. Under irrigated conditions doses of 40 and 80 kg of W per ha are considered optimum for toria, sarson and rapeseed respectively. For tarantira, 20 kg of W per ha is ancient. All the fertilizers should be drilled before sowing. Among the Brassicae, raya is most responsive to irrigation, followed by yellow sarson. Two irrigations, one at flowering and the other at pod formation, result in the maximum yield in the case of toria, sarson and raya. Its flowering is most economical, if there is water scarcity. Tarantira is not irrigated.
Harvesting is done as soon as the crop begins to turn yellow. Tma, which takes 75 to 90 days to mature, is the earliest crop to be harvested. Harvesting is done with hand-sickler. Threshing is done by beating with a wooden stick the seed bearing part of the plants, taken in convenient bundles or by trampling them under the feet. Winnowing is done with by slowly dropping the threshed produce from a basket held shoulder-high. The seed after being dried in the sun is stored in gunny bags or bins.
PETS AND DISEASES. The most serious pests of rapeseed and mustard are the mustard aphid (Lipaphis erysinbi (Holt) syn. Rhopalosiphun pseudobrwsicae (Davis), mustard sawfly (Athalia proximo King) and cutworm (Agrotis ypsi" Poott.). To control aphidy the spraying of Methyl Demeton 0.02% or 1imetboate 0.03% or Phosphomidon 0.0V/ two or three times, depending on the intensity is recommended. The mustard sawfly is controlled by dusting 10% BHC at the rate of 25 kg per ha. Cutworms are controlled by drilling into the soil 5% dust of Aldrin or Heptachlor or Chlordane at the rate of 25 kg per ha.
Alternaria blight (Alternaria brassicae Bork.) is the most widespread and destructive disease of rapeseed and mustard, whereas rust (Cystopus candidus) is serious in certain areas. Spraying with Dithane M-45 or Difolaton at the rate of 11 kg per ha is recommended for controlling these diseases. Orobanche, a phanerogamic parasite, has also been reported to be serious in Punjab and in certain parts of Uttar Flradesh. Hand-pulling of the plants of the parasite and a long rotation are recomnended. Yield. The average yield of rapeseed and mustard is about 500 kg per ha. Under good crop management, toria, which is a short-duration crop, gives a yield of about 450 to 650 kg per ha, sarson 800 to 1,000 kg and rai 1,000 to 1,200 kg per hectare.
OIL AND PROTEIN QUALITY IN THE BRASSICAE. The oil of rapeseede and mustard possesses a Sizable amount of crucie acid (38 to 57%), together with linolenic acid up to 4.7 to 13.0 % . The oleic and linolenic acid, which have nutritive value, together
constitute only about 27 per cent. It is desirable to increase the quantity of oleic and linolic acid and erucic acid. A lower proportion of erucic acid will make the oil more palatable, nutritive besides reducing metabolic disorders.
The Protein contained in rapeseed and mustard normally ranges between 24 and 30%. On the whole-seed basis and between 35 and 40% on the meal basis. But the presence of toxic glucosinolates in the mustard cake is unsuitable as source of human protein and is at present use as a manual and as a cattle feed.
VARIETIES. The varieties of different forms of rapeseed differ greatly in branching habit, maturity, shape and colour of foliage, colour and size of flower, seed, etc. The principal improved variety recommended for cultivation are given in table 2