Rapeseed & mustard are believed to be originated from Europe & Asian continent primarily India & China respectively. They require temperate climate and are annual crops. For better production, cooler climate is required but extreme cold climate with frost & fog will lead to lesser production. Mustard & Rapeseed both belong to Brassicaceae family.
Rapeseed is one of the cash crops of Nepalese farmers. Among the oilseed crop cultivated area of Nepal, 90% of land is cultivated with Rapeseed (Tori). According to research, yield with improved varieties is 20 times higher than local varieties in case of rapeseed.
- Oil extracted from mustard, rapeseed & sarsoon is used as cooking oil, lighting purpose, pickle making.
- Improved varieties of rapeseed consist of 40-45% oil, Sarsoon contains 42-47% & mustard contains 36-42% oil with considerable amount of protein.
- Yellow seed consists of 2% higher oil than brown colored.
- Oilseed cake is used as animal feed or organic manure with average 4.9% nitrogen, 2.5% phosphorus & 1.5% potassium.
These crops require higher temperature during its vegetative stage whereas lower temperature during its reproductive stage. Maximum temperature for this crop is 35-40 degree Celsius. Seed sowing should not be done if the temperature is higher than 35 degree Celsius as seed cannot germinate at this higher temperature. Seed sowing is optimum during daytime with 28 degree Celsius of night temperature. At temperature of 35 degree Celsius, irrigation should be given only at night time. High relative humidity can cause aphid attack & blight.
Light soil is best for these crops. Soil ranging from sandy to loamy soil having sound drainage system is best suited for these crops. Clay soil content must be less than 40 %. It cannot thrive in acidic soil & recommended pH is 6-7.5. Higher amount of organic matter is relatively better for these crops.
Manuring & Fertilization:
Recommended dose of inorganic fertilizer is 60: 40: 20 kg NPK/ha. During irrigated condition, half dose of nitrogen with full dose of P & K are applied during seed sowing with application of remaining half dose of nitrogen 20-25 days after sowing at first irrigation period.
Area deficient in Sulphur will not have satisfactory yield of these crops so, 20 kg Sulphur with 1kg boron per hector is recommended to apply during field preparation. Areas deficient in zinc should be applied with 10-15 kg of zinc sulphate per hector which helps in higher yield.
Field should be tilled fine breaking clods and planked for these crops. 3-4 times ploughing is essential followed by planking. Apply well decomposed FYM 8-10 tons/ha before 20-25 days of sowing the crop. Normally seeds are germinated after 4 days of sowing in best conditions. Field with less moisture should be sowed with one night-soaked seeds followed by planking for better germination. Seed should be sowed only 3-4 cm deep. Soil should be fine but not like powder because after rainfall it may form crust surface. Also seed should be sowed in field with high moisture content which can cause decay of seeds.
For higher yield of oilseed crops, timely sowing is one of non-expensive method. Late sowing cause low yield of these crops which cannot be over-come by applying higher nitrogen dose or increasing plant density. Late sowing cause short reproductive phase which lead to short pod formation & filling period eventually causing low yield with lower oil content. At later stage invasion of insects & disease in these crops is also higher. Rapeseed (Tori) should be sowed from second week of Bhadra to third week of Aswin whereas for mustard (rayo) it can be sown upto last week of Aswin. Late sowing usually causes Alternaria blight & aphid attack. According to scientific research report yield decreases by 46% of crop sown within 15th Aswin than that of crop sown at 15th Kartik. Argemone weed invasion & other weed also attack less when sown in time or early sowing is done.
Sowing & Seed rate:
Broadcasting: High plant density with low yield. 10 kg seed/ha
Line sowing: Rapeseed = 4-5 kg/ha & 5-6 kg/ha for Mustard (rayo).
Seed is mixed with sand for uniform sowing due to very small size.
Spacing: Rapeseed = 30 *10-15 cm (RR * PP), Mustard = 30-45 * 10-15 cm
Thinning is carried out after 10 days of sowing.
To prevent from Sclerotinia & root rot diseases seed is treated with Thiram & Captan @ 2.5 gram/kg of seed or Bavistin @ 2 gram/kg of seed. These diseases are highly prevalent in Chitwan & Nawalparasi district of Nepal. High relative humidity causes these diseases.
According the research report, weed cause 24-70% loss in rayo so, weed control is essential. 1 hand weeding in rapeseed & 2 hand weeding in mustard is essential. Basalin, fluchloralin, isoproturon or pendimethalin (stomp 34) can be used to control the weed of rayo or tori. Fluchloralin @ 1lit/ha or Pendimethalin @ 1.5 lit/ha is applied before sowing.
Mostly these crops are cultivated in non-irrigated land. If irrigation is available it is applied at 20-25 days after sowing in rapeseed & 25 days after in mustard followed by second at 55-60 days after sowing. Irrigation at flowering period helps in higher yield.
Harvesting & Threshing:
When pods turn 75% yellow then they are ready for harvesting. Harvesting is carried out in morning period to avoid shattering effect. Threshing can be done with stick or using thresher operated by tractors. Moisture of 8% is maintained before storing.
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Source: Hamro sampada