1 SEMI-DRY BED METHOD
Good for areas where irrigation is not assured, where shochum
is common, and in areas where low temperature is a problem
at the seedling stages.
• Prepare a well-levelled field with fine pulverized
soil.
• Apply well-rotten FYM and thoroughly mix with the
soil. About 3 kg will be enough for a seedbed of 1 m x 3 m.
• Make raised beds 10-13 cm high, 1 m wide, and any
convenient length.
• Broadcast unsoaked dry seeds uniformly on the seedbeds.
One "Drey" or 1.2 kg seed will be sufficient for
an area 1 m x 6 m.
• Cover the seeds using a thin layer of fine soil mixed
with well-decomposed FYM.
• Irrigate the bed immediately after sowing. The beds
should be just soaked. Never flood.
• Check the moisture of the seedbed and irrigate when
necessary.
The seedlings will be ready to transplant 40-60 days after
sowing, depending on altitude and temperature.
2 DRY BED METHOD
This method is commonly practised by farmers. It is similar
to the semi-dry bed method, but without raised beds. Farmers
broadcast seeds very thinly and do not irrigate. Sowing with
closer spacing and light irrigation can produce good seedlings.
3 WET BED METHOD
This method is good for areas where irrigation is assured,
and where low temperature is not a problem. This method is
not desirable where shochum is very common.
Plough, puddle and level a conveniently located plot. Apply
enough FYM before puddling. Make slightly raised beds, 10-13
cm high, 1 m wide and any convenient length.
Soak the seeds in clean water for 24-36 hours. Then rinse
the seeds, drain and incubate them for 36-48 hours. During
incubation keep them moist and warm in half-filled, loosely-tied
sacks. Every 12 hours drench the sacks and turn them upside
down to even out the temperature.
Broadcast the pre-germinated seeds uniformly on the beds.
One Drey of seeds will be enough for a seed bed of 1 m x 6
m.
Maintain just enough water to continuously saturate the beds
for the first week. Thereafter gradually increase the water
level as the seedlings grow. Never let the beds dry out.
The seedlings will be ready to transplant 20-25 days after
sowing depending on the temperature.
4. POLYTUNNEL METHOD
A polytunnel cover is used over the bed to protect seedlings
from cold and provide higher seedbed temperatures for seed
germination and growth while raising seedlings for first crop
in rice double cropping. Minimum temperature required for
the germination of rice seed ranges from 9-13oC. Normal air
temperature during the first week of Feb. in Wangdi Punakha
Valley averages only 4-8oC. A polytunnel cover increases the
temperature to 10-12oC, making seed germination and growth
possible.
• Prepare a well levelled field with fine pulverized
soil.
• Make raised beds 4 to 5 inches high, 1m wide, and
of any convenient length.
• Sow seeds evenly on the seed bed as in a semi-dry
bed nursery.
• Cover the seeds with fine soil mixed with FYM (1 :
1 mixture)
• Irrigate the beds to ensure sufficient moisture for
seed germination. Sprinkle water or give light irrigation
through the channels to soak the beds. Never flood the seed
beds.
• Bamboo or "Kempah" hoops should be placed
over the beds 80 cm apart down the length of the bed, pushing
the ends firmly into the soil.
• Medium weight transparent polythene sheet should be
placed over the hoops long and wide enough to cover the beds.
The edges of the polythene should be covered with soil to
hold them down to the ground.
• Check the moisture frequently to enure that there
is enough supply and, whenever necessary, irrigate by raising
the polythene sheet.
• After seedling emergence, the plastic tunnel should
be opened every morning (9 to 10 a.m.) to let in more sunlight
and prevent day temperatures from getting too high. The tunnel
should be closed again in the evening (3 to 4 p.m) every day
to keep the seedlings warm at night.
• Irrigate the nursery as and when required preferably
during the day.
• Seedling vigour will depend upon the soil temperatures
and growing conditions. Normally, seedlings should attain
3-4 leaf stage after 40-45 days of sowing.
For further information contact
Mahesh Ghimiray, Field Crops Sector, RNR-RC, Bajo
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