RASING OF NURSERY AND PLANTATION OF MUGA HOST PLANT SOM
North-East is one of the mega bio diversity centres of the world with flourishing green forests and suitable climatic conditions harbouring varied flora and fauna including the silk producing insects. Among all the five commercially exploited silk, four varieties are produced in the region including muga silk (Antheraea assamensis).
It is polyphagous in nature. Som, Persea bombycina is the primary host plant of muga silkworm.
NURSERY TECHNIQUE FOR MUGA HOST PLANTS, SOM.
The seeds of the major host plant of muga silkworm, viz. Som remain viable for a short time (2-5 months) and show poor germination. Seed sown in nursery bed with suitable cultural practices ensures better germination (80%) and produce quality seedlings with 85% post transplantation survivability.
Seed Bed Preparation:
• Select well-drained high land in a shady place.
• Plough the land up to 30 cm depth and level.
• Make 2x1 m beds and elevate the same up to 15 cm.
• Maintain a gap of 30 cm between two beds for cultural operation and proper drainage.
• Apply 5 cft FYM and mix thoroughly with the soil.
• Collect mature seeds from the plants during April/May in lower Assam and May/June in upper Assam and other NE states.
• De-pulp the seeds in running water.
Storage and seed viability:
• Test seed viability by floating test in water.
• Select the seeds, which settle at the bottom.
• Dry the seed in shade.
Seed sowing and seed dressing:
• Prior to sowing soak the seeds for 24 hours in water and treat the seeds with Bavistin @ 2g per kg seed.
• Sow 2 kg seeds (approx) per bed at a depth of 1 cm and 1.5 cm apart.
Transplantation of seedlings to poly tubes:
After 6 months transplant the seedlings to 20 cm long and 30 cm diameter polytube filled with 1:1:1 Soil : Sand : FYM.
Make copious Irrigation once in a week to the polytubr seedlings.
Ensures uniform growth.
CULTIVATION & MANAGEMENT OF MUGA HOST PLANT, SOM.
Muga silkworm is usually reared by the rearers on unorganized tall Som trees. Futher, due to lack of proper plantation technique, the plants show long gestation period of 5 years. Hence, a package of practices for plantation of Som has been developed.
• Select well-drained high land for plantation.
• Plough the plot up to a depth of 30 cm, make pits at 3 x 3 m spacing and fill the pits with 0.5 cft well decomposed FYM.
• Use high yielding S-3 or S-6 variety of som.
• Transplant 9-12 month old seedling into the pits.
• Complete plantation within May to August.
• Apply FYM @ 0.5 cft / plant/year up to 4th year and 1.0 cft from 4th year onward by making 6-8 inches deep ring around 2 feet circumference of the plant.
• Apply NPK @50:25:25 up to 4th year of plantation and 100:50:50 from 4th year onward through ring method during April-May and September- October.
• Provide initial pruning at 6 ft during 5th year followed by periodical pollarding/heavy pruning (step up/step down) after rearing to maintain the canopy at 10-12 feet for effective management of rearing.
• Periodical weeding should be done manually and/or by using tiller.