Production Technology of rice crops in Bangladesh

Production Technology of rice crops in Bangladesh

Land and soil

Medium high land to lowland is suitable for rice cultivation depending on growing

season. Any land type can be brought under rice cultivation; but its cultivation may

not be economical. Clay and loamy, slightly acidic to slightly alkaline soils are

suitable for rice cultivation.

Seed rate

Seed rate varies depending on crop establishment methods. For example, directseeded

rice (DSR) requires more seed rate than transplanted ones. Direct seeded

upland rice: 50-60 kg/ha; Transplanted rice: 8-10 kg/ha for one seedling/hill and 16-

20 kg/ha for 2-3 seedlings/hill would be required.

Seed treatment and soaking

Good quality seed is the prime requirement for a good harvest. Use of properly filled,

healthy seeds would ensure 5-20% higher yields than poor quality seeds. Good seeds

can be sorted out easily. Dissolve 375g urea in 10 litres of water and put 10 kg seed

into the container and stir seeds by hand. Fully filled seeds will be deposited at the

bottom of the container. Discard unfilled floated seeds from the top. Remove good

seeds from the container; wash it 3-4 times with clean water. If the sorted seeds are

spotless, seed treatment is not essential. However, seed may be treated in 52-550C hot

water for 15 minute. Seed may also be treated with Carbendazim fungicide @ 2-3 g/l

of water for 12 hours. One kilogram seeds should be used for each litre of water.

After 12 hours of seed treatment, it should be washed with clean water.

Seed soaking: Seed soaking time is 12-24 hours depending on water temperature

followed by incubation for germination. Incubation period for germination in Aus and

Aman season is about 48 hours and for Boro season is 72 hours.

Time of sowing

Time of sowing and its subsequent management greatly influence grain yield of rice

in different growing seasons. Seeds can be sown directly in the main field for directseeded

rice (DSR); but transplanted culture requires sowing seeds in seedbed. A

generalized sowing time is shown below:

Type of rice culture Sowing time

Direct-seeded upland 15 March to 30 April

Transplanted Aus (T. Aus) 30 March to 20 April

Transplanted Aman (T. Aman)

• Photoperiod insensitive varieties 15 June to 15 July

• Photoperiod sensitive varieties 20 July to 30 July1

Dry season irrigated (Boro)

• Short duration varieties 15 November to 30 November (in seedbed)

• Long duration varieties 01 November to 20 November (in seedbed)

Seedbed preparation

Clay and loamy fertile soils are essential for

seedling raising. However, if fertile soil is not

available then 2 kg organic fertilizer, 4g triple

super phosphate, 7 gm muriate of potash per

square meter needs to be added. After 10 days

of seeding, 7g urea and 10 gm gypsum may

require for healthy seedling raising. Land

should be plowed and cross plowed 3-4 times

followed by laddering and keep the soil

submerged by 5-6 cm water for 7-10 days.

Finally bed soil is made soft and muddy by

plowing and laddering. One meter wide bed is

prepared lengthwise of the land. There should Standard seedbed for growing rice seedlings

1 meter 25 cm

1Seeding for BRRI dhan46 can be done up to 10 August

be 25-30 cm space in between two beds from which soil is removed at 5-7 cm depth

and spread over the bed. Similar way soil of border areas is removed and spread over

the bed. Finally, bed soil is leveled by a flat wooden plank and kept undisturbed for

about 3-4 hours for seeding pre-germinated seeds. Fifty to 60 gm seed/m2 is used in

the seed bed. The canal formed in between two beds can be used for irrigation and

drainage purposes.

Land preparation and transplanting

Land for direct-seeded upland rice is generally prepared either in dry or optimum soil

moisture conditions. Three to four plowing followed by laddering or harrowing may

require for a good tilth depending on soil types. Land for transplanted culture is

prepared in wet conditions to make the soil soft and muddy. Three to four plowing

and cross plowing followed by laddering may require for transplanting. However, rice

can also be transplanted in zero tillage conditions, provided that the soil is soft and

there are no weeds or stubbles. At final plowing and laddering, land should be

properly leveled for keeping similar water depth throughout the field.

Transplanting: Seedlings are uprooted carefully before transplanting. In general, 20-

25 day-old seedlings are transplanted in Aus season, 25-35 day-old in Aman season

and 35-45 day-old in Boro season. One vigorous healthy seedling can be used in a

hill. However, 2-3 seedlings/hill may be utilized at 2-3 cm depth. Transplanting

should be done in rows to facilitate intercultural operations. Row to row distance

should be 20-25 cm and plant to plant, 15-20 cm. If seedlings are dead or hills are

missing, re-transplanting should be done within 7-10 days.

Fertilizer application

Balanced use of fertilizers is essential for satisfactory grain yield. Fertilizer rate

depends on weather, indigenous soil fertility, variety, growth duration and yield

potential etc. Depending on growth duration, yield and season variable amounts are

needed for satisfactory grain yield (Table 1).

Table 1. Fertilizer rates and application methods

2Those land which can give less than 1.0-1.5 t/ha grain yield in Boro season and less than 2.0-2.5

t/ha in T. Aman season without fertilization

3Those land which can give less than 3.0-3.5 t/ha grain yield in Boro season and less than 3.5 t/ha

in T. Aman season without fertilization

Season

Growth

duration

Urea-TSP-MPGypsum-

Zinc

sulphate

(kg/ha)

Method of application

More than

150 days

300-97-120-

112 -10

Less than

150 days

and BRRI

dhan50

260-97-120-

112 -10

Boro

Haor areas 200-90-120-60-

10

Low fertile land2

One third urea at basal, 1/3rd at 4-5 tillering/hill stage

and 1/3rd at 5-7 days before panicle initiation (PI) stage.

Medium fertile land3

Urea in three equal splits at 15-20, 30-35 days after

transplanting (DAT) and the rest amount at 5-7 days

before PI.

Whole amount of triple super phosphate (TSP), muriate

of potash (MP), Gypsum and Zinc fertilizers at final land

preparation for both low fertile and medium fertile lands.

N.B. If N deficiency exists after PI, 30-37 kg urea/ha

may be added.

Aus 100-115

days

127-52-60-0-0 Whole amount of TSP, MP, Gypsum and Zinc

fertilizers at final land preparation. One third urea at

basal, 1/3rd at 4-5 tillerings stage and 1/3rd 5-7 days

before PI.

More than 195-52-82-60- 0

145 days

excluding

scented rice

172-52-82-60-0

Low fertile land

One third urea at basal, 1/3rd at 4-5 tillering/hill stage

and 1/3rd at 5-7 days before PI.

Medium fertile land

Urea in three equal splits at 7-10, 25-30 DAT and the rest

amount at 5-7 days before PI.Whole amount of TSP, MP,

Gypsum and Zinc fertilizers at final land preparation for

both low fertile and medium fertile lands.

Less than

125 days

127-52-82-60-0 Whole amount of TSP, MP, Gypsum and Zinc

fertilizers at final land preparation. One third urea at

basal, 1/3rd at 4-5 tillerings stage and 1/3rd 5-7 days

before PI.

Photoperiod

sensitive

172-52-82-60-0 Whole amount of TSP, MP, Gypsum and Zinc

fertilizers at final land preparation. Two third urea at

basal and 1/3rd at 5-7 days before PI.

Aman

Scented rice

and BRRI

dhan32

90-52-60-30-0 Whole amount of TSP, MP, Gypsum and Zinc

fertilizers at final land preparation. One third urea at

basal, 1/3rd at 4-5 tillerings stage and 1/3rd 5-7 days

before PI.

Some additional points on fertilizer application time and methods:

• Organic fertilizers should be added at first plowing during wet season.

• In light textured soils, potash fertilizer should be added in two splits- two third at

final land preparation and 1/3rd at 5-7 days before panicle initiation (PI).

• Carry over effect of zinc sulfate may be observed in succeeding two crops.

• Urea fertilizer needs to be added in every cropping season. It should be applied in

four equal splits for light textured soils. It is better to apply urea in 2-5 cm water

followed by incorporation mechanically.

• Zinc and sulfur fertilizers are to be added during final land preparation for Zn and

S deficient soils. However, they can be utilized after transplanting for correcting

deficiency symptoms in rice.

Use of urea super granules

Urea super granule (USG) is made

from urea, which looks like tablet.

Use of USG improves urea useefficiency

by 20-25%. Rice should be

transplanted in rows at 20 cm apart

for using USG in between four hills.

USG is placed at 7-10 cm deep into

soil at 15-20 and 7-10 DAT during Boro and Aus and Aman seasons, respectively. In

general, one grainule of 1.8 gm is used in Aus and Aman seasons; on the other hand,

one grainule of 2.7 gm is used in Boro season. So, it supply 110 kg urea/ha in Aus and

Aman seasons and 165 Kg urea/ha in Boro season. However, USG rate adjustment

may be required depending on soil fertility and yield potential of rice variety.

Irrigation

Rice can be grown without continuous standing

water. Generally, 2-4 cm standing water can be kept

up to 10-12 DAT and then reduced amount to

facilitate tillering and reduction of irrigation cost.

Since rice is mainly grown as irrigated crop during

Boro season, loss of irrigation water can be

minimized by using plastic and PVC pipes. Alternate

wetting and drying (AWD) technique can be employed to save irrigation water. In this

system 25 cm long and 7-10 cm dia PVC pipe is used in which 15 cm is perforated.

This perforated 15 cm is placed into soil vertically followed by removal of inside soil.

When water is seen at the bottom of the pipe, the land is irrigated at 5-7 cm water

depth. This technique is followed after crop establishment and continues upto

vegetative stage. Standing water should be maintained at PI to milking stage.

1.3 Intercultural Operation

Intercultural operations are to be done in between transplanting and harvesting. It

Urea super granule Urea super granule placement

Perforated PVC and installed pipe

in rice field.

includes gap filling within 7-10 DAT, fertilizer management, pest management, water

management, rouging and mowing. These have been discussed in separate headings.

Some of the important issues of intercultural operations are stated below:

Fertilizer management and pest control

• Excessive use of N fertilizer favors fungal and bacterial disease development along with

increased infestation of brown plant hopper, leaf folder, stem borer, gall midge, etc.

• Balanced use of potash fertilizer helps in controlling whorl maggot, green

leafhopper, yellow stem borer, brown plant hopper, etc.

Water management and pest control

• Plant hoppers and army worms could be controlled by draining field water.

• Alternate wetting and drying helps in controlling black bugs, plant hoppers, gall

midge, hispa, and most stem borers.

• Irrigation water helps in controlling grasshoppers, thrips, ants, white grubs, mole

crickets, root aphids, termites, root weevils and seedling maggots.

Pest Management

Weed Control

Grain yield loss of rice can be mitigated if weeds, insect pests and diseases are

controlled at the right time. As a thumb role, if rice fields are kept weed free for

initial one third of field duration (planting to maturity) of a rice variety, then crop loss

could be avoided. Weeds are generally controlled mechanically (hand pulling, use of

weeder, etc) and chemically. Weed control by herbicides is more profitable than hand

weeding. Pre-emergence and post emergence herbicides can be used for weed control.

Examples of herbicides are provided.

Table 2. Herbicides used for weed control in rice field

Name of herbicide Time of Quantity Remarks

application /ha

Machete 5G (Butachlor) 3-6 DAT 25 kg

Miracle 25EC (Oxadiazon) 3-6 DAT 2 L

Hunter (Pretylachlor) 3-6 DAT 1 L

Panida 33EC (Pendamethylin) 2-5 DAT 2.5 L Toxic for direct weeded rice

Topstar 400EC (Oxadiazyl) 3-6 DAT 188 ml

MCPA 500EC 3-5 leaved weeds 105 ml Toxic for direct weeded rice

MCPA 600EC 3-5 leaved weeds 105 ml Toxic for direct weeded rice

Sathi 10WP (Pyrajosulfuran ethyl) 3-5 leaved weeds 150 gm

Vachete 5G (Butachlor) 3-6 DAT 25 kg

Serius 10WP (Pyrajosulfuran ethyl) 3-5 leaved weeds 150 gm

Major diseases and control measures:

Bacterial leaf blight: This disease can infect rice plant at any

stage. Diseased seedlings die off in the bed known as krisek.

If diseased stem is pressed at the base, sticky bad odorous

ooze can be noticed easily. Older leaves are infected at PI

stage. Watery symptom initiated from the tip of the leaves

that gradually turns to yellow and finally as dried straw.

Stormy weather and rainfall favor this disease development.

Control measures:

• Use of balanced fertilizers.

• Use of additional 35-40 kg/ha potash fertilizer may cause disease symptom.

• Urea should not be top-dressed after hailstorms and disease development.

• If krisek develop, drain out water from the field and irrigate after 7-10 days.

• Burn straw after harvesting of diseased crop.

Ufra: This disease is caused by small thread worm like

organism, can not be seen by naked eyes. They infect collar

of young rice leaves. The micro organism suck sap, develop

small white spot, which gradually become brown and leaf

blade die out. Plant growth stunted depending on severity of

infestation. If disease develops at booting stage, twisted

panicles remain inside leaf sheaths.

Control measures:

• Apply 20 kg/ha Furadan 5G or Curator 5G.

• Burn straw after harvest.

• Keep land fallow for 15-20 days after plowing.

• No seedbed preparation in infested field.

• Follow rice-non rice cropping rotation.

Tungro: It is a virus disease, which can occur at seedling to

flowering stage. Green leaf hopper (GLH) is responsible for

the spread of this disease. Light green line alternate with

light yellow one appear parallel to veins in young leaves

followed by deep yellow or yellow-orange coloration of the

upper leaves. The infected leaves twisted slightly, plant

growth stunted with reduced tillering. Diseased plants are

comparatively shorter than healthier ones.

Control measures:

• Initially remove diseased plants and burry into mud.

• Destroy GLH through light trapping.

• Control GLH by spraying Melathion 57EC at 1 L/ha, MIPC 75WP at 1.12 kg/ha, etc.

Ufra infected panicle

Tungro affected rice plants

and virus carrier

Bacterial leaf blight

Sheath rot: A fungus disease develop on flag leaf sheath as

round or irregular brown spot. The spot gradually increase in

size and turn into dark grey color. Panicle emergence is

impaired at variable degree depending on severity of the

disease.

Control measures:

• Burn affected stubbles.

• Use balanced fertilizers.

• Spray Nativo, Folicur, exaconazole.

Sheath blight: A fungal disease generally found at tillering

stage. Initially grayish watery mark develops on leaf sheath.

Centre of the speck become gray surrounded by brown

margin. The spot gradually enlarged in whole sheath and

parts of leaf. Hot humid weather, excessive urea application

and densely populated plants favor disease development.

Control measures:

• Floating stubbles after final land preparation should be

removed and buried into soil.

• Apply potash fertilizer in equal two splits at final land

preparation and at last urea top dressing.

• Spray Nativo, Folicur or exaconazole.

Blast: A fungus disease, which may develop in the leaf (leaf

blast), node (node blast) and neck of panicle (neck blast).

Oval shaped brown spot, whitish or ash color at the centre

develop on leaves. Many spots merge together resulting in

dead leaf. Whole plot may be damaged because of this

disease. Low night temperature, high day temperature and

dew in the morning favor blast disease development.

Control measures:

• Add organic fertilizer.

• Keep standing water.

• Use seed from disease free field.

• Use balanced fertilizer. Suspend urea top dressing

• Apply 400 gm/ha Trooper, Nativo twice in 10-15 days.

Major insects and control measures:

Rice varieties tolerant to insect pests should be cultivated. There are many insects in

the rice field- some of them are predators, some are parasitoids and others are pest for

the rice crop. So, integrated pest management (IPM) technique should be adopted to

save beneficial insects. Control measures of some important insect pests are discussed

and some insecticides and rates for controlling rice insects are presented in Table 2.

Stem borer: Stem borer affected plants produce dead heart or

white head symptom depending on growth stage of rice

plants.

Control measures:

• Destroy egg mass.

• Control moth through light trapping.

• Use perching technique.

• Spray insecticide if 10-15% dead heart or 5% white head is observed.

• Burn stubbles.

Gall midge: This insect infests growing tillers, which turns

into onion shoot.

Control measures:

• Regular observation of field.

• Destroy adult insects through light trap.

• Use insecticide if 5% onion shoots are observed.

Rice hispa: Grub destroys internal leaf tissue and adult feed

on green leafy parts resulting in whitish leaf.

Control measures:

• Using sweeping net for destroying adults.

• Use insecticides if 35% leaves are damaged or 4

adults/hill or 5 grubs/tiller are observed.

Rice caseworm: This insect makes small cages by cutting

upper portion of leaves. Leaves of infested field are white.

These cages float on water in day time.

Control measures:

• Destruction of moths by light trap.

• Collect cages from water by hand net and destroy them.

• Drain water from the field.

• Use insecticides if 25% leaves are damaged.

Leaf roller: Larvae of this insect folds leaf and feeds on

internal green parts. Burning symptom appears when leaves

are severely damaged.

Control measures:

• Destroy moth through light trap.

• Perching.

• Use insecticides if 25% leaves are damaged at or before PI stage.

Gall midge and onion shoot

Rice hispa and damage

Rice caseworm

Leaf roller moth, larva

and damaged leaf

Stem borer moth, dead

hart and white head

Brown planthopper: This insect sucks cell sap from the base

of the plant. Plants dry up showing burning symptom which

is known as hopper burn.

Control measures:

• Transplant at 25 cm x15cm or 20 cm x 20cm spacing for

allowing light and air in the field followed by regular

inspection.

• Use balanced amount of urea.

• Drain water if insect is seen.

• Short duration variety may be cultivated.

• Use insecticides if 4 gravid females or 10 grubs or both are

found in most hills. Comm unity based control measures

are effective.

Green leafhopper: This insect sucks leaf cell sap resulting in

reduced plant growth. It is a virus disease carrier.

Control measures:

• Use of light trap.

• Use insecticides if green leafhopper is found in every sweeping

net and nearby existence of tungro affected plants.

Rice bug: This insect infest rice field at the milking stage of

rice plant. Pungent smell emit from the adult insect.

Control measures:

• Use light trap.

• Use insecticides in the afternoon if 2-3 rice bugs/hill are found.

Thrips: This insect infests at seedling and tillering stage of rice plant. Thrips make

lesion on leaves and sucks cell sap resulting in leaf folding longitudinally.

Control measures:

• Irrigate seedbed/field followed by urea topdressing.

• Use insecticides if severely infested.

Green leafhopper

Rice bug

Brown planthopper and

hopper burn

Table 3. Name of some insecticides and rates for controlling rice insect pests