Sunday, October 27, 2013

New Soil Testing Kit (SoilDoc) Has Developed for Third World Countries

New soil testing kit has developed by researchers of Columbia University and University of Maryland. The name of this soil testing kit is SoilDoc.  This New soil testing kit is developed for farmers in third world countries. This kit has designed with battery-operated instruments and other safe materials so that agricultural extension agents can handle it in the field easily. By this kit agricultural extension agents can test nitrogen, phosphorus, sulfur and potassium of the soil, as well as active organic matter, and certain soil physical limitations. The primary results of the soil tests are sent by mobile phone to a particular website. After performing calculations necessary doses are delivered back by the website through that mobile phone to the extension agent or farmers.

A  soil scientist named Ray Weil, PhD worked in Africa for several years.  This kit is the culmination of his work of several years. He worked under a project in some of the poorest areas of Africa.  At first he was working with common soil testing items. Soon he realized that  he needed more.  After returning to USA he found that, those items used for testing home aquariums are also work for soil tests with good results. Upon returning to Africa, he used this items in Africa. His colleague scientist Pedro Sanchez suggested that Weil create a product around his homemade kit. Then Pedro Sanchez worked on it. Recently Lydiah Gatere (A post-doctoral researcher at Sanchez's Center ) has contributed to the SoilDoc product.

A presentation will held about this soil testing kit on Monday, Nov. 4, 2013 at 2:45 PM in Tampa, Florida. The title of the presentation is "Field Kit Soil Tests to Assess Acidity, N, P, S and K Fertility in Kenyan Soils". Gatere will present it. The presentation is part of the American Society of Agronomy, Crop Science Society of America, and the Soil Science Society of America Annual Meetings, Nov. 3-6 in Tampa, Florida. The theme of this year's conference is "Water, Food, Energy, & Innovation for a Sustainable World".

Wednesday, October 23, 2013

Packets Of Rice Should Be Made Of Jute: Decided By Bangladesh Government

jute made bag

jute made sack
From 1st January, 2014 plastic made bags and sacks are banned for packaging rice. Instead of plastic bags jute-made bags must used. Bangladesh government has decided it at 26 September, 2013.  Remaining plastic bags must be utilized before December of this year.
Owners of jute mils of different areas of Bangladesh have welcomed this decision of Bangladesh Government because small jute-mils of Bangladesh will get animation now.  Jute-mils owners say that they are producing two types jute-made bags one is export quality bag which production cost is 60 to 70 taka and other type is for fulfillment of domestic demand of Bangladesh which production cost is  42 to 45 taka. On the other hand same carrying capable plastic bags are sold at 15 taka in markets. This is the reason why rice sellers and rice mil owners are using plastic bags instead of jute-made bags.

According to Bangladesh Jute Mils Corporation ( BJMC ) and Bangladesh Jute Mils Association (BJMA) 50 to 60 crore jute bags are produced in Bangladesh per year. BJMC is producing 38 crore jute-bags in year. Every year Bangladesh needs 50 to 55 crore bags for packaging cereals, fertilizers and sugarcane.

There are 40 jute mils in the greater Rangpur, Dinajpur amd Bogra districts of Bangladesh. Farmers and jute-mil owners of that area are now happy.

This news has published in PROTHOM-ALO ( 21.10.2013 )

Jute and Bangladesh
jute is known as golden fiber of Bangladesh. Bangladesh produces the best quality jute in world.

Why jute made bag is best rather than plastic made bag?
Plastics are not biodegradable. Dumping of plastics in soil is causing pollution. So plastic and plastic made bags are not Eco-friendly.
Om the other hand jute is biodegradable and decomposed in soil. Dumping of jute does not cause any hazard in environment. So jute made bags are Eco-friendly.
This the main reason why Bangladesh Government want to replace the plastic made bags by jute made bags though production cost of plastic bags is less.

Saturday, October 5, 2013

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.

Friday, October 4, 2013

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 .

Wednesday, October 2, 2013

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.

Tuesday, October 1, 2013

Saline Soils In Bangladesh

In saline soil excess amount of salts are present. Mainly NaCl is present in high amount. Salts of Mg, K, Ca also present in saline soil at low concentration. A white crust of salts is deposited on the surface of soil due to salinity. So other name of saline soil is white alkali. 

Characteristics of saline soil:
Normally pH remains below 8.5 ( 7.0 to 8.5 ) in saline soil. Electrical  conductivity values remain greater than 4dS/m. In saline soil exchangeable sodium percentage is less than 15 at 250 c.  The surface of coastal soils are slightly to moderately saline and sub-surface layers and substrata of the soils are highly saline.

The process by which salts are accumulated in the soils is known as salinisation.  Flooding of coastal water is the main cause of salinisation.  There are some others factors such as a) tidal action, b) depth of the ground water table and salt deposits, c) the nature of the soils, d) the effect of the river system and their discharges, e) precipitation and f) the slope of the ground and the proximity to drainage channels.

Causes  of  salinity:
1. Poor drainage system of agricultural lands and seepage of saline water  to the lands.
2. Irrigation with the high salt containing water  to the agricultural fields.
3. Continuous  shrimp cultivation in agricultural land is a major cause of introducing  salt in soils.
4. High water table with high salt concentration in coastal area increases the possibility of introduction of saline water in coastal area.
5. High temperature and low rainfall also increase the salinity in saline soils.
6. Weathering  of salt containing  parent materials  is one of the major cause of the increasing salinity in soils.
7. Tidal flooding is the main cause of introduction of saline water.
8. In dry season, capillary movement of  saline water ( upward ) causes salinity in soils.

Location of saline soil:
More than 2.9 ha land of Bangladesh is affected by saline water. Every year it is increasing. Chittagong, Barishal, Noakhali, Khulna and Patuakhali  districts are mostly affected by saline water.
The AEZs that are affected by saline water are
1. Gangas Tidal Floodplain  ( AEZ 13 )
2. Young  Meghna Estuarine Floodplain ( AEZ 18 )
3. Chittagong Coastal Plain ( AEZ 23 )
4. St Martin’s Coral Island (AEZ 24 )

Constrains to crop productions:
1. Water use efficiency  is reduced.
2. Occurrence of organic soil and extreme acid sulphate soil is one of the major constrains.
3. It reduces nitrate absorption.
4. In dry season that means in Robi season crop cultivation is hampered.
5. There is lack of fresh surface and ground water.
6. It inhibits germination of crop seeds.
7. Breakdown of soil aggregates is occurred.
8. Also ionic imbalance in soil is occurred.

Management of saline soil for crop production:
1. Flooding with fresh water is very effective though it is sometimes difficult.
2. Fertilizers should be applied in balance.
3. Irrigation must be done before sowing seeds or transplanting.
4. Higher seed rate and close planting is a effective practice against saline soils.
5. We have building embankment to control saline water in coastal area.
6. Application of organic matter and green manure during dry season.
7. Reducing shrimp cultivation in coastal area.
8. Cultivating  salt tolerant crops.

Result of salinity:
1. Growth of plants and yield reduced detrimentally.
2. Degradation of land is occurred.
3. The quality of water is reduced.
4. Infrastructures near the coastal  area or saline soil are damaged rapidly than non coastal area.