SOME SPECIAL VARIETIES RELEASED BY BRRI (BANGLADESH RICE RESEARCH INSTITUTE)

BRRI dhan48
1. It is a early variety.
2. It is developed for MONGA region. Because it is drought tolerant variety.
3. It is  cultivated in Aus season.
4. It’s life span is 110 days.
5. Yield of this variety is 5.5 ton per ha.

BRRI dhan49
1. It is a fine rice like Najershail.
2. It is developed for the region where water is logged for long time. Because it is a water logging resistant variety.
3. It is  cultivated in Aman season (T. Aman variety).
4. It’s life span is 135 days.
5. Yield of this variety is 5-5.5 ton per ha.

BRRI dhan50 (Banglamoti)
1. It is an aromatic fine rice and it is better than Basmoty in quality.
2. It is developed for the region where water is logged for long time. Because it is a water logging resistant variety.
3. It is  cultivated in Boro season.
4. It’s life span is 155 days.
5. Yield of this variety is 6 ton per ha.

BRRI dhan51
1. This variety is resistant to abrupt flood.
2. This variety can survive under flood water up to 14 days.
3. It is  cultivated in Aman season(T. Aman variety).
4. It’s life span is 145-155 days.
5. Yield of this variety is 4-4.5 ton per ha.


BRRI dhan52
1. This variety is resistant to abrupt flood.
2. This variety can survive under flood water up to 14 days.
3. It is  cultivated in Aman season(T. Aman variety).
4. It’s life span is 140-150 days.
5. Yield of this variety is 4.5-5 ton per ha.

BRRI dhan53
1. This variety is a salinity tolerant variety.
2. This variety can be able to tolerate 8-10 ds/m salinity.
3. It is  cultivated in Aman season(T. Aman variety).
4. It’s life span is 125 days.
5. Yield of this variety is 5 ton per ha.

BRRI dhan54
1. This variety is a salinity tolerant variety.
2. This variety can be able to tolerate 8-10 ds/m salinity.
3. It is  cultivated in Aman season(T. Aman variety).
4. It’s life span is 135 days.
5. Yield of this variety is 5.5 ton per ha.

BRRI dhan55
1. This variety is a salinity tolerant variety.
2. This variety also  tolerant to drought and cold.
3. It is  cultivated in Aus season and also in Boro season.
4. It’s life span is 105 days in Aus season and 145 days in Boro season.
5. Yield of this variety is 4-5  ton per ha in Aus season 7 ton per ha in Boro season.

BRRI dhan56
1. It is a early variety.
2. It is developed for MONGA region. Because it is drought tolerant variety.
3. It is  cultivated in Aman season ( T. Aman variety).
4. It’s life span is 110 days.
5. Yield of this variety is 4.5-5 ton per ha.

BRRI dhan57
1. It is a early variety.
2. It is developed for MONGA region. Because it is drought tolerant variety.
3. It is  cultivated in Aman season ( T. Aman variety).
4. It’s life span is 105  days.
5. Yield of this variety is 4-4.5 ton per ha.

Source- BRRI (Manual- Adhunik Dhner Chash -2010)

ABOUT RICE ( IN BANGLADESH )

Origin: Origin of rice is Indo-Bangladesh subcontinent.
Species: Mainly species is present and they are Oryza sativa and Oryza glaberrima.
Chromosome: Rice has 24 chromosomes.
Land: For rice cultivation sandy loam to clay loam soil is required. Soil pH should be 4.5 to 7.5.
Seed rate: For broad cast rice 70-80 kg/ha and for transplanting rice  40-45 kg/ha
5oo meter square nursery bed is required for for seedling of 1 ha of land ( for transplanting rice ) .
Seedling age: For Boro rice - 45 days seedlings, for T. Aman 30days seedlings, for T.Aus 25 days seedlings.

RICE

Yield: for local variety 2.5-3 ton/ha for HYV 6-7 ton/ha
Spacing: 25cm by 15 cm is standard and 2-3 seedlings/hill for hill cultivation
Rice has special affinity to water though rice is not a hydrophyte plant.
BR3 ( Biplob) a variety of Bangladesh can grow any season of the year.
Life cycle: Life cycle of Boro rice is 135-150 days and it is a highest life cycle. Because in winter season temperature remains very low, and the rate of plants slow down.
Vitamin - A rich rice variety is golden rice.
Rice contains 7% protein.
Rice varieties developed in Bangladesh are ( from BRRI ) BR1 to BR26 except BR13 and BRRI dhan 27 to BRRI dhan 57.
Local varieties: Nizershail, Pajam, Biroy, Latishail etc.
Aromatic varieties: BRRI dhan 34, Banglamoti ( BRRI dhan 50 ), Tulsi mala, Kalizira etc.
Also Ratoon rice is grown in Bangladesh.
SRI ( system of rice intensification ): It is a special type of rice production system where 8-14 days old seedlings are transplanted in 1 seedling/hill with wide spacing.
Aus rice: BR 21, BR 24, BR 26, BRRI dhan 42, BRRI dhan 43, BRRI dhan 48.
Aman rice: BRRI dhan 49, BRRI dhan51, BRRI dhan 52, BRRI dhan 53, BRRI dhan 54, BRRI Hybrid Dhan 4.
Boro rice: BRRI dhan 28, BRRI dhan 29, BRRI dhan 50, BRRI Hybrid dhan 1,BRRI Hybrid dhan2, BRRI Hybrid dhan 3.
Broadcast Aman rice or  floating Rice: Habiganj Aman 1,2,4.
The plot size of for rice nursery bed is 10m*1.25m*15cm
Gap between two adjacent beds of rice seedlings is 50cm
20 meter square area can be covered by the seedlings of 1meter square.
Urea should not be applied on standing water on field.
In low pH soil and wet land, P is less available.
If P is applied in excess amount, availability of Zn, Fe and Cu decrease.
BRRI has 9 local stations in all Bangladesh.
Yield of rice: In Bangladesh 4.01ton/ha.
In world Bangladesh is the 4th  highest Rice producing country.
IR8 is the first HYV rice variety in Bangladesh.
BRRI released 58 rice varieties. 54 are inbreed and 4 are hybrid ( up to 2011)
BRRI has introduced Drum Seeder, BRRI weeder, BRRI open drum thresher, BRRI dryer, BRRI power winnower.
Cold stress, heat stress, drought stormy wind are the causes of chuffiness of rice seed.

Insect Pest Of Rice: Rice Leaf Folder Or Rice Leaf Roller

1. larva in action   2. adult rice leaf roller moth

a leaf roll

Rice leaf folder or roller  is considered one of the major harmful insect pest of rice. It is common in maximum rice growing are. It’s scientific name is Cnaphalocrosis medinalis and this insect belongs to the family Pyralidae of Lepidoptera order. These insects do harm when they are at larvae stage. They do harm by rolling leaf and reducing photosynthesis area.

Nature of Damage:
The destructive stage of this insect is the larval stage. At this stage they fold the leaves longitudinally before feeding. They tie the leaf margins with the threadlike silk. They feed the green mesophyll of leaf inside the folded leaf. They feed by scraping. At first and second instar larvae feed within the slightly folded areas of leaf. At late second instar feed and roll up the maximum area of a leaf . There is one larva in one leaf. After feeding one leaf, larva moves to another leaf. In this way one larva can damage a number of leaves. Feeding reduce the photosynthesis area of leaves. So vegetative growth and finally yield is hampered. Yield loss is maximum when flag leaf is damaged.

Control Measure:
1. Though cultural control or method is a effective method, it reduces the population of rice leaf folder or roller but not eliminate the insect totally.
a. Rice leaf roller in takes shelter at grasses and weeds during off season and continue  their life cycle. So we must clean the surroundings of rice field area or we can manage weeds or grasses.
b. Slit and judicious use of N fertilizer is needed.
c. Hand picking of the larvae should be done.
d. Ratooning of rice crop should be avoided. Because these insects will increase their population in ratoon crops of rice.
e. Stubble of rice crops should be avoided.
2. Mechanical control is an effective method to control the rice leaf roller moths. It is suggested by the agriculturist because this method does not pollute the environment as the chemical method does.
We can capture adult moths by light trapping to reduce the population of this harmful insect in our rice fields.
3. Resistant variety cultivation also appreciated.
4. Biological control is best to control rice leaf roller insects. Biological control is the method of controlling an insect population by it’s natural enemy or predator or parasites.
a. Eggs of the rice leaf roller is parasitized by Trichogramma sp. So we may introduce Trichogramma sp. In our rice field to control rice leaf roller when they lay eggs.
b. Larvae of the rice leaf roller is parasitized by Xanthopimla emaculata. So we may introduce Xanthopimla emaculata in our rice field to control rice leaf roller when they are in larval stage.
3. Pheidole sp. ( a sp.of ant ) is a predator of the caterpillars of rice leaf roller moths.
5. Chemical control is not appreciated by scientists and agriculturists. Because chemicals used in crop fields pollute our environment in many ways, do harm to our health and wild lives. This control method is our last step to control the insects when there is a possibility of reducing the yield in huge amount.
Spraying of any following insecticides at economic threshold level of 10% damage leaves:
Fenitrothion at the dose of 454 ml per acre area, Malathion at the rate of 404 ml per acre area, Carbaryl at the rate of 688 g per acre area, Cypermethrin at the rate of 202 ml per acre area.

Insect Pest Of Rice: Rice Hispa

symptoms of infested field

rice hispa

Rice Hispa ( Scientific name is Dicladispa armigera ) is major insect pest of rice. Rice hispa belongs to the Chrysomelidae family of Coleoptera order. Both adults and grubs are destructive to rice crops. Mainly leaf blade of rice plants are damaged by them. By this way photosynthesis is hampered and yield is reduced.

Nature of Damage:
The upper surface of leaf of rice plants is scraped by the adult insects. Sometimes it is seen that only lower epidermis of the leaves remains to eat! So many white streaks that are parallel to the midrib are appeared at the damage areas. Tunnels are made between two epidermal layers by grubs. By this way irregular translucent white patches are created by the grubs. These translucent white patches stared from the tips of the leaves to the base of the leaf blades. Leaves becomes whitish and finally dry off if severe infestation is occurred. So the photosynthesis area of plants is reduced and plants become stunted due to lack of foods. The number of grains is reduced and grains are not well filled. 

Control measures:
1. Cultural control is good control measures for rice hispa.
a. In off season rice hispa feed and breed on the grasses or weeds near the rice fields. So must manage the weeds that are present in farm or rice fields.
b. Ratooning of rice plants must be avoided and stubble should be uprooted so that rice hispa cannot take shelter during off seasons.
c. Optimum dose of N fertilizer should be applied.
d. Early varieties may be cultivated to avoid rice hispa buildup.
e. Tip of the leaves should be pick out when rice hispa are seen on the leaf tips.
f. Infested leaves must be removed until plants go to booting stage.
g. During transplanting infested leaves of seedlings must be removed.
2. Resistant varieties must be cultivated.
3. Biological control of insects or pests are appreciated at first than chemical control.
a. Many ichneumonid wasps and braconid wasps are parasitoids of the larvae of rice hispa. So we may increase the population of these parasitoids in rice fields.
b.  Rhinocoris fuscipes is a predator of adult rice  hispa. So we may consider this predator to control rice hispa.
4. Chemical control is always discourage by scientist and agriculturist. If we manage our fields properly, chemical control is not needed. We may go for chemical control when severe attack is happened. We can apply Fenitrothion at the rate of 454ml per acre, Dimethoate at the rate of 454 ml per acre and carbaryl at the rate of 688g per acre.

Insect Pest Of Rice: Rice Bug

Rice Bug is one of the most economically important insect pests of the world. In rice producing countries is one of the major problems. That means rice bug is very common pest of rice. Scientific name of the rice bug is Leptocorisa acuta. This insect belongs to the family named Coreidae of Hemiptera order.

This harmful stage or destructive stage of this insect is not only the adult stage but also nymphs stage. Most of the damages are done by this insect when rice grains are at milky stage. Rice bug  sucks milk of the grains and for this reason rice grains remain unfilled.

Nature Of damage:
Nymphs and the adult bus feed on endosperm of the developing grains of rice.  Growing nymphs are active feeders than adult insect but adult rice bugs do more damage than nymphs of this insects. Because adult rice bugs remain more times on the grains and feed there for a long times than nymphs. They attack grains when grains are at milking stages. But they remain on the grains from milking stage to ripening stage. Nymphs and adults insert their proboscises at the point of lemma and palea ( where lemma and palea meet ).  So characteristic symptoms that brown spots are seen on the grains. As adult bugs suck the milk of grains, the grains remains unfilled and at later panicles are shriveled. Infested straw has an off-flavor that why cattle do not want to eat that straw.  Grains that are partially damaged by bugs, has also as off flavor and these grains are not cooked.

A Rice bug on grains

Damaged Grains

Control Measures:
When we are going for rice cultivation, at first we must consider preventive measure to control the insects and diseases. We must give priority to cultural control and biological control than chemical control. Because chemicals do harm to our environment where biological control is eco friendly. We can practice chemical control to save our crops when severe attack has done by rice bugs.
1. Cultural control
  Rice bugs feed on different grasses near the crop fields and they also breed on these grasses during  the off-season. So or first target is to uproot these unnecessary grasses.
2. Mechanical control
  We can use light traps, sticky traps and other traps to capture adult insects.
3. Use of resistant variety is effective.
4. Biological control
  Gryon nixoni ( small scelionid wasps) is an egg parasitoids of the rice bug. So we can apply this egg parasitoids in our rice field to control rice bugs.
  Meadow grasshoppers ( Conocephalus longipennis ) are feed on rice bug’s egg. So it is a good idea that if we increase the population of Meadow grasshoppers in our rice fields, Meadow grasshopper will feed eggs of bugs and the population of rice bugs will decrease rapidly.
   Many spiders such as Tetragnatha javana, Neoscona theisi prey on nymphs. So we may introduce these type spiders to our rice fields to control rice bugs.
5. Chemical control is  our last option to control rice bug.
  Carbaryl 5% and Malathion 5% are very effective against rice bugs. We may apply this insecticides @ 25 kg per ha as dust to control insects. We must not use chemicals indiscriminately because chemicals are very harmful for human life, wild life as well as our beautiful environment .

Insect Pest Of Rice: Rice Stem Borer

Rice stem borer is a very common insect pest in world, specially in India, Pakistan, Bangladesh regions. Yield reduces due to attack of this insect.
There are mainly three stem borer of rice. They are a) Rice yellow stem borer ( Scirpophaga incertulas), b) Dark headed stem borer ( Chilo polychrysus ) and c) Pink headed stem borer (Sesamia inferens ).
All of them are belong to the Lepidoptera order and Pyralidae family.  At larvae stage they attack the stem of rice.

Nature of Damage:
Only the caterpillar stage of these insects are very destructive in rice field. Adult insects do not harm in crop field. Adult insects hatch eggs on the leaf sheaths and a week after hatching larvae become active for it's destructive activities. From the leaf sheaths larvae moves toward the stems and bore the stems. When larvae stay into the pith, they feed on the inner surface of the stem wall ( mainly soft tissue of the pith ). This feed is stared from the base to the apical part of the plants. The central leaf whorl turns into brownish color and dries off rapidly, if larvae attack at the vegetative stage of  rice plants. But the leaves of the plant remain healthy. This symptom is called dead heart symptom. Tillers can not bear panicles and become dry. Sometimes panicles emerge but do not produce grains on the top of it. As the panicles are empty, they become whitish in color and remain in straight. This symptom is very conspicuous in the rice field. This symptom is known as white heads symptom.

whiteheads symptom

A larvae inside the stem

Control Measure:
1) Control by cultural practices
a) We have to remove and destroy all the stubble after harvesting the crops.
b) After ploughing a flood irrigation should be given to kill the larvae.
c) Tips of the seedlings should be clipped if eggs are seen on the leaf of seedlings.
d) Application of excess amount of N fertilizer should be avoided.
e) If we apply slag into the field, it will increase the silica into the plans and this will make plants more resistant against rice stem borer.
2) resistant variety ( BR-3 / Biplob ) should be cultivated.
3) Mechanical control
We may use light trap to capture adult moth in the rice field.
4) Biological control
a) Telenomus, Tetrastichus and Trichogramma are the egg parasitoids of stem borer of rice. So we may import these egg parasitoids into the rice fields.
b) Longhorn grasshopper feeds on egg masses of the stem borer, Coccinellid beetles and carabid beetle feed on the larvae of the stem borer.
c) Spider can attack the adult moth ( rice stem borer ) by trapping them in webs.
d) At day time dragonflies ans birds are the predator of rice stem borer.
5) chemical control
As the larvae remain inside the stem, so systemic insecticide is effective to kill the larvae. Monocrotophos may apply 607ml per acre of land, Diazinon may apply 688 ml per acre, Fenitrothion may apply 454 ml per acre, carbofuran may apply 6.8 kg per acre.