SEED PRODUCTION TECHNIQUE
Rayo Broad leaved mustard in Nepal
- Brassica junceae var rugosa, cruciferae
- Nepali name: Rayo saag
- In Nepal, BLM occupies first position in terms of area and production among leafy vegetables. It is widely adopted and can be grown from Terai to hills of Nepal. It is rich in vitamin A,B,C and iron, calcium and protein. It can be used in lean period by curing and making “Gundruk”. It has high nutrritional and economic importance.
- Annual herb produce large broad leaves.
- It is also soft leafy vegetables.
- Seed is brown, yellow in colour
- Khumal broad leaf
- Marpha Broad leaf
Climatic condition and soil
ü It is a cool season crop, so before flowering, it requires cool climate.
ü At the time of flowering and seed maturation, it requires warm and hot climate.
ü Loamy soil with sufficient humus and high water holding capacity is best for the crop.
ü Optimum pH range for better growth and development should be 6-7.
Flower and pollination
v The flower is yellow and the flower is complete containing 6 androecium, 1 gynoecium.
v Although it is cross pollinated crop , from seed production point of view, it is consider as self pollinated crop.
v It can be cross pollinated from one variety to another variety but cannot be cross pollinated from one genus to another genus like cauli, turnip,etc.
Method of seed production
Seed to seed method
Sowing and Transplanting Time
ü Although it is a cold season crop, from seed production point of view it can be cultivated from Ashoj in mid-hill and Terai.
ü Transplanting is done in Ashoj-Kartik. Plant growth takes place upto Magh and Bud initiation and flowering takes place in Magh-Falgun. And seed maturation takes place in Baisakh.
ü In mustang, Transplanting is done in Falgun-Chaitra and seed maturation takes places in Ashar-Shrawan.
Row to row spacing= 75cm.
Plant to plant spacing = 45 cm.
v 30 gm seeds/ropani
v 1500-1800 plants/ropani
v Fertilization Per ropani 1000 kg well rotten FYM, 10 kg complexal and 2 kg MOP should be mixed in soil at the time of land preparation.
v 4 kg/ropani urea should be required for seed production.
v 2 kg urea should be applied 40-50 DAT.
v Remaining 2 kg urea should be top-dressed after bud initiation in the form of ring shape.
Seedling production Technique
- Land should be made clean and dry after tillage operation.
- 1 m width, 3m length and 15 cm height raised bed should be made.
- Line sowing is done. And after sowing, seed is covered with sand and mulching is done with dry straw.
- Irrigation should be done in every evening time with rose can.
- After seed germination, straw should be removed.
- 25-30 Days after germination, Transplanting is done.
Irrigation and intercultural operation
1) 5 DAT, irrigation with rose can is done.
2) If it is necessary, thereafter irrigation through irrigation channel is done.
3) 40-45 DAT, Earthing up is done with spade. At this time, top dressed of Urea is done.
4) Second interculture operation is done after initiation of flowering.
Selection and Rouging
- Selection and Rouging is done on the basis of foliage characteristics and on the basis of ancestral character.
- Only true to type plants are permitted for flowering which are of qualitatively potential.
- Less qualitative plant like disease plant, damaged plants, insect attack plant, unhealthy plants, etc. are rouged before flowering.
- Maximum permitted off-type for foundation seed is 0.1o % and for certified seed is 0.20 %.
- Minimum no. of field inspection on Rayo is 3.
- 1st at before full grown stage, 2nd at full grown stage in non heading types and 3rd at flowering.
ü For Foundation seed, isolation distance should be 1600 m and for certified seed, it should be 1000 m
Importance of field inspection in BLM
ü To maintain the true to type variety
ü To maintain the varietal purity
ü To avoid the mechanical mixture
ü To assess the performance of crop under the given agro-climatic condition
ü To avoid natural crossing with off types plants, volunteer plants, diseased plants,etc.
ü To assess the flowering behaviour of plant
ü To remove and rouge the off types , volunteer plants and other weeds plants.
Harvesting, Threshing and Winnowing
- Harvesting of plant is done before complete drying of plant when the pod become yellow.
- Plant should be kept in heap in dry shadow place for 3-4 days.
- At 2 days interval, the heap should be aerated by inverted turning of plant in heap.
- Threshing is done either by manual or beating with stick or mechanical method or by any other means.
- The shattered seed should be collected and winnowing should be done.
Drying and Storage
- The winnowed seed should be sun dried 3-4 times.
- The moisture percentage should be 6-8 % .
- The seed should be stored in air tight tin or aluminium container.
30-35 kg seed/ropani in context of Nepal.
Insects and Diseases
Cutworm, cabbage butterfly, Aphids,etc.
Damping off, Downy mildew, Leaf spot, White rust , Powdery mildew,etc