| These recommendations are made for the low altitude (150-600
m) southern belt that include Sarpang, Samtse and Samdrupjonkhar
for irrigated rice culture.
VARIETIES
BR 153
• BR 153 is a high yielding, tropical semi dwarf variety
bred in Bangladesh.
• It is 100 110 cm tall and matures in 140 150 days.
• It has good resistance to diseases and pests and is
tolerant of poor soils and management.
• It has slender white grains.
• Yields of 2 3 t/acre can be obtained under average
management conditions.
BW 293
• BW 293 is a tropical, high yielding variety developed
in Sri Lanka.
• It is 75-85 cm tall and matures in 140-150 days from
sowing
• It has slender white grains with intermediate to high
amylose content.
• It has higher yield potential than BR 153 under similar
input levels.
CROP ESTABLISHMENT
Nursery sowing
• Optimum sowing date: June .
• Seed rate: 50-60 kg/ha.
• Use clean and healthy seeds.
• Seedlings can be raised using wet or semi-dry bed
methods (see rice seedling production leaflet).
PREPARATION OF FIELD
Land preparation is one of the important factors that influences
rice yield. It provides good physical, chemical, and biological
conditions of the soil for optimum plant growth.
• Two or three ploughings are needed, followed by puddling
and levelling.
• Irrigate the field before ploughing, if dry.
• Plough thoroughly and then flood.
• Drain the water slightly and plough, rotovate or harrow
as needed to break clods, bury weeds and to puddle and level
the field.
• A final puddling and levelling may be required just
before transplanting.
Repair and maintenance of bunds and the incorporation of chemical
fertilizers, if any, should be done before the final puddling.
MANURES AND FERTILIZERS
FYM contributes significantly to crop nutrition and soil
condition. It is desirable to encourage the use of FYM.
Our recommendation is to apply about 5-8 t/ha FYM basally,
and topdress with 35 kg N/ha 35-40 days after transplanting.
If adequate FYM is not available, apply 80:40:30 NPK kg/ha.
Half the N and all the P should be applied as the basal dose.
Topdress the remaining N 35-40 days after transplanting. For
local varieties, limit N to 50 kg/ha to prevent lodging.
Sesbania aculeata (Dhaincha) can be grown for 6-8 weeks then
incorporated as green manure during land preparation. Sow
Dhaincha at a rate of 50-60 kg/ha in May. Topdress 35 kg N/ha
at PI for higher yields.
TRANSPLANTING
Transplanting time: July.
Traditional random method can be used if:
• Weed pressure is expected to be low.
• Butachlor will be used.
• The terraces are narrow and small.
Line planting should be done if weeding will be carried out
with a rotary weeder.
• Use a rope to give a row spacing of 20 cm and within-row
spacing of 15-20 cm.
A plant density of 25-35 per square metre is optimum.
WEED CONTROL
Weeds are serious competitors of rice. They compete for water,
nutrients and sunlight, and reduce grain yields.
Where weed pressure is low or moderate, 2 hand weedings 20
and 40 days after transplanting are sufficient. If hand weeding
is to be done, plants should be closely spaced and the first
weeding performed no later than 30 days after transplanting.
For weeds other than shochum, Butachlor is very effective.
It is applied 3-6 days after transplanting at the rate of
30-40 kg/ha of 5% "Punch" granules.
As weeding is laborious, and the use of herbicides is undesirable,
there must be emphasis on indirect complementary weed control
methods like good land preparation, proper water management,
and use of weed-free seedbeds and seeds.
WATER MANAGEMENT
After transplanting keep the water level low for 4-7 days
until the seedlings recover. Water level should then be increased
as the crop grows ensuring adequate water from tillering to
flowering.
If the supply of water is limited, continuous flooding is
not possible. In this case irrigate at short intervals but
do not let the field become excessively dry and crack. Flowering
is the most critical stage when rice should not be exposed
to moisture stress.
Drain water from the field 10-15 days before harvest to enhance
ripening.
PLANT PROTECTION
Insect pests and diseases are a major concern due to high
temperature and humidity. Integrated pest management approach
is recommended which involves varietal resistance, cultural
and biological control methods, and use of pesticides at a
need based level.
HARVEST
Under normal conditions harvesting begins from the first
week of October. Harvest the crop when at least 85% of the
upper portion of panicles turns straw coloured. Some leaves
and stems may still be green at grain maturity, particularly
of improved varieties.
Local varieties shatter very easily, and timely harvest will
minimize grain losses.
For further information contact
Mahesh Ghimiray, Field Crops Sector, RNR-RC, Bajo
|