Everything you need to learn about rapeseed and mustard cultivation, harvest and growth.
Introduction to Rapeseed and Mustard (Sarisha, Rai, Laha, Tori, Toria):
India grows a number of oilseed crops belonging to the family, Cruciferae, which are referred to as rapeseed and mustard.
They are generally divided into the following groups:
i. Brown Mustard:
Commonly known as rai, raya or laha—Brassica juncea (L.) Czem. & Coss.
ii. Sarson:
(a) Yellow sarson — Brassica campestris L. Var. yellow sarson Prain
(b) Brown sarson — Brassica campestris L. Var. brown sarson.
iii. Toria:
Commonly known as lahi or Maghi lahi — Brassica campestris L. Var. toria Duth.
iv. Taramira or Tara:
In trade, rai is referred to as mustard and the others, namely, sarson, toria and taramira, as rape seed. Banarsi rai (Brassica nigra Koch.), which is not included in any of the four groups, is grown as a garden crop and used as a spice.
The mention of sarson in old Ayurvedic literature suggests the antiquity of these crops in India. All available records indicate that rai (Brassica juncea) was introduced from China into north-eastern India. Eastern Afghanistan along with the north-western parts of India is regarded as one of the independent centres of origin of brown sarson (Brassica campestris Var. brown sarson).
So far as yellow sarson (Brassica campestris Var. yellow sarson) is concerned, much diversity of forms is found in the eastern parts of India. Taramira (Eruca sativa) is believed to have originated in southern Europe and North Africa.
India has the largest area in the world under rapeseed and mustard and the production is also the highest in this country. The Brassica crops occupy about 4 million hectares and produce about 2.5 million tonnes of seed annually. The total production in the country is expected to be about 4 million tonnes shortly.
UP, Haryana, Punjab, Bihar, MP, Rajasthan, W. Bengal and Orissa are the chief states, where these crops are grown. Besides India, they are chiefly cultivated in Pakistan and China. The crops are grown in Europe, Canada and USSR also, but the forms are different from those of India.
The plants are annual herbs having a height of 0.45 to 1.75 m. Roots generally long and tapering. Branches in toria and brown sarson arise at an angle of 30° to 40° and in yellow sarson at an angle of about 10° to 20°. Inflorescence is a corymbose raceme. Flowers are yellow or white.
The four petals are either spread apart or overlapping. Stamens 6 are in number and tet- radynamous. Carpels 2 are ovary hypogenous and syncarpous. In yellow sarson, ovary may be tri-or tetra-carpellary. Fruit a siliqua, two-, three- or four- valved, depending on the number of carpels in the ovary. Seeds are globose.
Climate and Soil Required for Rapeseed and Mustard:
Rapeseed and mustard crops require cool temperature for good growth. In India, they are grown both in tropical and temperate regions in the rabi season, from September – October to February – March. These crops grow well in areas having 25 – 40 cm of rainfall.
These crops do very well in light to heavy loams. While rai may be grown on all types of soils, toria does best in loam to heavy loam and sarson in light loam.
Rape and mustard are generally grown in mixture with other crops. Toria is, however, chiefly grown as a pure crop. In UP, it is rotated with early maize or jowar for fodder.
Cultivation of Rapeseed and Mustard:
A fine tilth is required for these crops. In irrigated areas, 4 to 6 ploughings, and, in rain-fed areas, 1-2 ploughings may be given. In the case of mixed cropping, the seed rate depends on the proportion of rape to the main crop. When grown pure, 5 kg of seed is considered proper for one hectare in so far as all rapeseeds and mustard are concerned.
When grown in mixture with other crops, the time of sowing of rape and mustard depends on the sowing of the main crop. The optimum time for sowing toria is the first half of September. A little earlier sowing is done if wheat is the following crop. Sarson and rai should be sown from 25th September to 15th October and from 30th September to 15th October respectively. With regard to taramira, the entire month of October is considered suitable.
In mixed cropping, rape and mustard are sown in rows 1.8 to 2.4 metres apart, across the main crop, and, in a pure crop, sowing is done in rows 30 cm apart. Thinning is done after three weeks in order to maintain a plant to plant distance of 10 to 15 cm.
Manuring and Fertilization:
The optimum dose of nitrogen for rape and mustard in rain-fed areas is 40 kg per hectare, whereas in irrigated areas, 40, 60 and 80 kg are considered optimum for toria, sarson and rai respectively. So far as taramira is concerned, 20 kg of nitrogen per hectare is sufficient. The fertilizer is to be applied before sowing by drilling.
Irrigation:
With regard to irrigation, only two, one at the time of flowering and the other at the time of pod formation, are enough, because they increase the yield of toria, sarson and rai to the maximum. No irrigation is, however necessary for taramira.
Harvesting and Yield:
Of the oil-yielding Brassica crops, toria is the earliest to mature and.it takes about 75 to 90 days to be ready for harvest, whereas rai, yellow sarson and brown sarson mature in 110 to 180 days, 130 to 160 days and 105 to 145 days respectively. The crop is harvested as soon as it begins to turn yellow.
Sickles are used for harvesting the crops. Threshing is conveniently done by beating the fruits on the plants, taken in bundles, with a wooden stick. Trampling them under the feet of bullocks is also quite common. Natural air current is made use of for the purpose of winnowing. The seed is finally dried and stored.
The average yield of rape and mustard is 500 kg per hectare. Under good crop management, the yield of toria is reported to have been pushed up to 800 to 1000 kg and that of sarson to 1000 to 1200 kg per hectare. Rai, the highest yielder of all rape and mustards, is known to have yielded 1500 kg per hectare and even more.
Oil and Protein Content:
The oil is extracted from the seed in mills or ghanis. The content of oil in rape seed and mustard varies from 30 to 48 per cent and that of protein varies from 24 to 30 per cent on the whole seed basis.
Uses of Rapeseed and Mustard:
The oil is edible and is used as a cooking medium in certain parts of India, particularly in the eastern states. It is also used for purposes of illumination. The Seeds, which are pungent and have a characteristic flavor, are commonly used as a condiment in both vegetarian and non-vegetarian preparations. The oil cake is a good cattle feed and a manure.
Varieties of Rapeseed and Mustard:
Some of the principal improved varieties recommended for cultivation in different states are:
Diseases of Rapeseed and Mustard:
The common diseases of rapeseed and mustard are:
(i) Al- ternaria blight caused by Alternaria brassicae, the most wide-spread disease, which can be controlled by treating the seed with hot water (50°C for 10 minutes), practising a long crop rotation or by spraying seed plots with 1% Bordeaux mixture or 0.2% Zineb or Ziram at the pod formation stage.
(ii) White rust caused by Albugo Candida, which can be controlled by clean cultivation and by removing and burning the affected plant debris.
(iii) Downy mildew caused by Peronospora brassicae, which can be controlled by spraying with 0.2% Zineb, Ziram or Maneb. Besides these, Orobanche, a phanerogamic parasite, has also been found to be serious in Punjab and in parts of UP. This can be controlled by pulling out the parasite by hand or by practising a long rotation.
Insect Pests of Rapeseed and Mustard:
The most serious insect pests of rapeseed and mustard are:
(i) Mustard aphid (Lipaphis ery- simi), which can be controlled by practising clean cultivation, spraying 0.05% Lindane or 0.02% Phosphamidon or 0.03% Monocrotophos or Dimethoate.
(ii) Mustard sawfly (Athalia proxima), which can be controlled by hand-picking the larvae or dusting 5% BHC if the attack is severe.
(iii) Cutworm (Agrotis ipsilon), which can be controlled by drilling 5% Aldrin dust or Heptachlor or Chlordane into the soil at the rate of 25 kg per hectare.