Rice (Oryza sativa) cultivation

 

Land preparation

One of the less obvious but equally important factors in cultivation of rice is land preparation. Although the produce of a crop of rice is dependent upon many other obvious factors: irrigation, fertilization, weeding, pest and disease control. Because proper land preparation promotes a good environment for seed/soil contact (which will promote rapid crop growth while reducing competition from weeds), it is imperative that land preparation be thorough and timely. In preparing land for rice cultivation, the following should be put into place.

 

Brushing and Clearing

Land preparation in inland valley swamps begins with a thorough brushing and clearing. Farmers are encouraged to begin with the larger stumps and bushes, since grasses and other weeds grow back very quickly and are best left until just before the first ploughing. Bushes and tree limbs should not be left to overhang the edges of the paddies. The initial brushing and clearing should be completed about one month before planting.

 

Repairing Water Control Structures

Remove weed that have grown in the channels and dig out accumulated silt and clay. Clean and repair all water control structures – irrigation gutters, drains, and sluice gates. The flow of water through the channels is impeded by weeds and sediment, and their capacity is greatly reduced. Repair dikes that may have eroded, paying particular attention to the headband and peripheral (irrigation) gutters. Remember: it is always easier to make repairs and alterations to the water control system before you plant.

 

Ploughing and Puddling

After the water control structures have been cleaned and repaired, ploughing may begin. Flowing is done in inland valley swamps for several reasons:

• Weed Control (weeds are destroyed and prevented initially from competing with rice seedlings)
• Incorporation of Organic Matter (weeds and crop residues such as straw and stubble are incorporated into the soil, where they become converted into plant nutrients through decomposition)
• Transformation of Surface Soil into a Puddle (for ease in transplanting)
• Establishment of a Reduced Zone (increases the availability of some nutrients by maximizing contact between rice root hairs and soil particles)
• Levelling (during ploughing the soil can be moved around until the plots are level, thus improving water control)
• Formation of a hard Pan (repeated ploughing to a certain depth will create an impervious hard layer, which will reduce water losses and mineral losses through leaching)

To be most effective, ploughing must be done thoroughly and timed properly. In inland valley swamps, the ideal schedule calls for two ploughing and one puddling. Timing these operations correctly is very important.

 

First Ploughing

The first ploughing, or deep ploughing, should be completed 2-3 weeks before transplanting begins. There are several reasons for such an early start:

• to protect seedlings against the adverse effects of harmful substances generated by decomposing organic materials
• to allow seedlings to utilize the nitrogen rich ammonium (NH4) released during the decomposition process
• to spread out the work load for the farmer (thorough ploughing is very hard work and is best done a little bit at a time)

Flood the plot for several days before ploughing to soften the soil and make the work easier. On the day of ploughing, drain off excess water. Using a hoe or shovel, turn the soil to a depth of 15-20 cm (6″-8″) Begin near the edges of the plot (so you can repair the bunds if necessary) and work toward the centre. Keep the plot flooded after the first ploughing until transplanting. If the plot is allowed to dry out, 20-700 kg of valuable nitrogen could be lost into the air through a process known as denitrification depending on the soil, its previous cropping history and other factors. Note: Many farmers will at first be reluctant to plough 2-3 weeks in advance of transplanting. The traditional practice in many areas is to wait until the seedlings are nursed and almost ready to plant before starting to plough. Encourage farmers to complete the first ploughing before parsing their rice. The 2-3 week lead time will give the organic matter sufficient time to decompose, and the toxic substances released during organic matter decomposition will dissipate before the seedlings are planted.

Second Ploughing

The second ploughing should take place 7-10 days after the first ploughing. Break up the softened clumps of soil and incorporate straw, stubble, and weeds that may have germinated. Remove large roots that will not decompose, as well as large stores. Lower the water level in the plot during the second ploughing to reveal high spots which will need to be levelled. Re-check the water control system and make minor adjustments as needed.

 

Puddling

Puddling should take place, -10 days after the second ploughing and one day before transplanting. Puddling is usually done with bare feet (and draft animals, in areas where they occur). Bush poles are often used to help maintain balance and to break up remaining soil clumps. Puddling further incorporates germinating weeds, facilitates levelling, and breaks down the soil structure into a soupy mud suitable for transplanting. If a basal application of fertilizer is intended, broadcast the fertilizer just before puddling so that it will be well mixed into the soil. After puddling, the soil will be ready for transplanting.

 

Methods of Ploughing

Ploughing may be accomplished in several ways:

• ploughing by tractor is generally rot suited for inland valley swamps because tractors cannot move easily from plot to plot without destroying water control structures. Furthermore, in flooded soils tractors often are simply too heavy. Initial cost and operating costs are high.
• ploughing by rotor-tiller (2-5 horsepower) is gaining acceptance in many parts of the world, despite high initial cost and maintenance problems. In broad swamps with large plots, the rotor-tiller can be extremely effective and economical. Rotor-tillers cannot be used in recently-developed swamps containing many stumps and large roots.
• ploughing by animal is extensively practiced with excellent results in most of Asia, but less frequently in Africa (where the se of draft animals is less widespread in general).
• Most draft animals are able to work only 3-4 hours per day without supplementary feeding, end they require considerable care.
• ploughing by hand, though tedious and time-consuming, is the major method of ploughing inland valley swamps throughout most of Africa. Hand ploughing requires the farmer to spend many hours standing in water and thus facilitates the spread schistosomiasis. http://www.nzdl.org/gsdlmod?e=d-00000-00—off-0cdl–00-0—-0-10-0—0—0direct-10—4——-0-1l–11-en-50—20-about—00-0-1-00-0–4—-0-0-11-10-0utfZz-8-00&a=d&cl=CL2.18&d=HASHd437e4577406c1595cde6e.10

 

Climatic and soil requirements

Rice cultivation is possible only in areas with good rainfall, as the crop requires standing water for growth. A monthly rainfall of 100-200 mm is a must and about 125 cm is during vegetative season. And there should be no water at ripening stage. Rce being a tropical and sub-tropical plant, requires a fairly high temperature, ranging from 20° to 40°C. The optimum temperature of 30°C during day time and 20°C during night time is considered favourable for its growth and development. Sunlight is also, a must for all plant lives, a source of energy. During the ripening period of last 35 to 45 days, the yield is most benefited by sunlight. Bright sunshine with low temperature during ripening period of the crop helps in the development of carbohydrates in the grains. The effect of solar radiation is more profound where water, temperature and nitrogenous nutrients are not limiting factors. Rice grows on a variety of soils like silts, loams and gravels. However, clayey loam is well suited to the raising of this crop. https://raindropsbasmatirice.wordpress.com/2012/07/24/climatic-conditions-for-rice-cultivation-4-2/

 

Variety of rice

Worldwide there are more than 40,000 different varieties of rice, though only a small number offer the quality acceptable to be grown commercially in the U.S. In the United States. Rice types can be divided into long, medium, and short grain. Limited waxy rice and arborio is produced, as well as some aromatic and specialty varieties.

The primary differences in these rice is their cooking characteristics and, in some cases, a subtle flavour difference. From a nutritional standpoint they are equal and indeed can often (with the exception of waxy rice or Arborio) be interchanged in recipes.

 

Long Grain Rice
Long grain rice has a long, slender kernel, four to five times longer than its width. Cooked grains are separate, light and fluffy.

Medium Grain Rice
Medium grain rice has a shorter, wider kernel (two to three times longer than its width) than long grain rice. Cooked grains are moister and tender, and have a greater tendency to cling together than long grain.

Short Grain Rice
Short grain rice has a short, plump, almost round kernel. Cooked grains are soft and cling together.

Sweet Or Waxy Rice
U.S. sweet rice is short and plump with a chalky white, opaque kernel. When cooked, sweet rice loses its shape and is very glutinous. Sweet is more often used in commercial product formulations. The starch and flour from sweet rice is used in frozen products as a binder for gravies, sauces, and fillings because it is resistant to breakdown during freezing and thawing, unlike some corn or wheat starches. http://www.foodreference.com/html/art-rice-varieties.html

 

A vast number of rice varieties is grown around the world. While it is true that no “perfect” variety exists, for every combination of environmental features, management practices, and farmer preferences it is usually possible to select a suitable variety. This chapter describes the kind of things to look at when you select a rice variety. Like the farmer, you will find yourself relying both on tradition and on trial and error The traditional varieties provide the security of known response that have proven themselves over the years. The trials and errors are what make the work creative and offer the hope of improvement.

 

Varietal Characteristics

Listed below are the varietal characteristics most often considered by farmers in selecting a rice variety for cultivation:

1. Duration

• most cultivated varieties range from 90-270 days in duration (germination to harvest)

Importance:

• determines how many crops can be grown in one year
• important in coordinating the growing season with the availability of water
• important in coordinating the farming calendar with other family subsistence activities

1. Height of the Plant – rice varieties are generally classified by height as follows:

 

Tall	161 cm – 350 cm	(63″ – 140″)
Medium	75 cm – 160 cm	(30″ – 62″)
Short	below 75 cm	(below 30″)

Importance:

• determines crop’s ability to withstand deep flooding
• affects harvesting practices

 

1. Stature of the Plant – rice varieties are generally classified by stature as follows:

• Spreading
• slightly spreading
• spreading

Importance:

• affects spacing during planting
• determines plant’s ability to shade out competing weeds

 

1. Tillering Capacity

• rice varieties are said to be either: high tillering (each seed produces 26-35 tillers) medium tillering ( each seed produces 10-25 tillers)
  low tillering (each. seed produces 2-10 tillers)

Importance:

• directly affects yield
• determines planting practices
• determines amount of seed nursed
• affects plant’s ability to recover from damage inflicted by pests or weather

 

1. Pancile Size/Grain Weight

Importance:

• directly affects yields

1. Resistance to Toxicities

Importance:

• determines suitability to local soil and water conditions

 

1. Resistance to Pests/Diseases

Importance:

• determines suitability to local rest/disease conditions

 

1. Response to Fertilizer

• many improved varieties have been bred to respond favorably to fertilization with chemical fertilizers, i.e. they show a marked increase in growth rate, height, number of tillers, panicle size, and grain weight.

Importance:

• should be compatible with farmer’s fertilization practices (or nonfertilization practices)

1. Milling and Cooking Characteristics

• depending on the nature of the husk, rice varieties may be either easy or difficult to mill. Furthermore, cooked rices vary considerably in appearance, texture, taste, smell, and starch content.

Importance:

• significantly affects farmer’s preferences

 

Traditional vs. Improved Varieties

In many parts of the world, farmers have been growing rice for handreds or even thousands of years. During this time, many varietes have interbred or mutated and gradually adapted to local conditions. Conversely, through trial and error farmers have developed traditions of cultivation practices which assure consistent fair yields with relatively little management. The majority of subsidence farmers still rely on time-honored management practices -to cultivate their traditional varieties. Characteristics typically found in such varieties include:

• long, duration
• high tillering
• spreading stature
• resistance to drought/flooding;
• resistance to pests/diseases
• competitive with weeds
• adapted to low nutrient levels
• high milling and cooking quality

 

Although the traditional varieties usually yield lower than the improved -varieties, the extension agent should be extremely careful about suddenly encouraging farmers to abandon a time-tried variety for one which differs considerably from what they are used to growing The single most important characteristic of most traditional varieties is their ability to produce sustained yield, however modest. The introduction of a new “miracle” variety, even if advantages is initially, may prove disastrous in the long run if the farming system over time proves incapable of providing the nutrient inputs necessary for the production or sustained high yields. As a rule, high yields require high (fertilizer) inputs, and it is easy to make the mistake of either creating a fertilizer dependency or depleting a balanced farming ecosystem by introducing a variety which extracts nutrients faster than they are being replenished. The extension agent should not be afraid to experiment with new varieties – but s/he must be careful not to encourage the farmer to succumb to the short-sighted temptation to maximize present yields. The traditional varieties, however low-yielding, have endured over thousands of years because they are hardy, reliable, and ecologically safe.

 

Planting

The two main practices of establishing rice plants are transplanting and direct seeding.

 

Transplanting

It is the most popular plant establishment technique across Asia. Pre- germinated seedlings are transferred from a seedbed to the wet field. It requires less seed and is an effective method to control weeds, but requires more labor. Seedlings may be transplanted by either machine or hand.

 

Direct seeding

It involves broadcasting dry seed or pre-germinated seeds and seedlings by hand or planting them by machine. In rainfed and deepwater ecosystems, dry seed is manually broadcast onto the soil surface and then incorporated either by ploughing or by harrowing while the soil is still dry. In irrigated areas, seed is normally pre- germinated prior to broadcasting http://ricepedia.org/rice-as-a-crop/how-is-rice-grown

 

Rice crops can be either direct seeded or transplanted.

In direct seeding, seeds are sown directly in the field. While in transplanting, seedlings are first raised in seedbeds before they are planted in the field.

When choosing the suitable planting method, the locality, soil type, rice ecosystem, and availability of inputs and labour, should be considered.

 

Choosing when to plant is crucial to establishing the crop in the field. Timely planting into a well prepared seedbed will help produce a fast growing, uniform crop that will have higher yields and better competition against weeds and other pests. The best time to plant depends on locality, variety, weather, water availability, and the best harvest time. Planting at the same time (or within a 2week window) as the neighbouring fields can help to minimize insect, disease, bird, and rat pressure on individual fields. Direct seeding requires 60−80 kg of seeds per ha, while transplanting only requires 40 kg per ha, at 2 plants per hill. http://www.knowledgebank.irri.org/step-by-step-production/growth/planting

 

Direct seeded crops require less labour and tend to mature faster than transplanted crops.

In this method, plants are not subjected to stresses such as being pulled from the soil and re-establishing fine rootlets. However, they have more competition from weeds.

Depending on the land preparation method used, direct seeding can be done in two This method is usually practiced for rain-fed and Deepwater ecosystems. Farmers sow onto dry soil surface, then incorporates the seed either by ploughing or harrowing.

• Broadcasting

1. 1. Broadcast 60−80 kg of seeds uniformly by hand or in furrows in 1 ha of field.
   2. Make shallow furrows by passing a furrower along the prepared field.
   3. After broadcasting, cover the seeds using a spike-tooth harrow.

• Drilling

Precision equipment, such as the Turbo Happy Seeder, can be used to drill seeds.

Drill 80−100 kg of seeds per ha.

Seeds are placed by the machine into both dry and moist soil, and then irrigated. A smooth, level seedbed is necessary to ensure that seeds are not planted at depths greater than 10−15 mm.

In this technique, fertilizers can be applied at the same time as the seed. Manual weeding also is easier in machine-drilled crops than in broadcast crops.

• Dibbling

Dibbling or hill planting is usually practiced along mountain slopes or where plowing and harrowing are difficult.

Use a long wood or bamboo pole with a metal scoop attached at the end for digging holes.

Drop the seeds into the holes and cover them with soil.

ways:

In wet fields, direct seeding can be done either through broadcasting or drilling seeds into the mud with a drum seeder.

Broadcasting

Broadcast 80−100 kg per ha of pre-germinated seeds to recently drained, well-puddled seedbeds or into shallow standing water.

If water in the field is muddy, allow 1−2 days for it to dry before broadcasting.

If water is drained from the fields after broadcasting, seeds are re-introduced 10−15 days after first seeding.

Drum seeding

Drum seeders are used for fast planting. It operates best on a well-leveled, smooth, and wet seedbed. However, seeders may be clogged if the soil is sticky or if the machine is poorly designed.

Prepare 80 kg of pre-germinated seeds per ha.

 

Transplanting

Transplanting is commonly practiced as a method of weed control for wet or puddled fields. It requires less seed but much more labor compared to direct seeding. Also, transplanted crops take longer to mature due to transplanting shock. Majority of rice fields in Asia are manually transplanted. Depending on soil type, one hectare of rice requires 25 to 30 person days to establish.

 

 

 

Manual transplanting can be done in two methods:

 

Random Method

In random method, seedlings are transplanted without a definite distance or space between plants.

When transplanting is done at random, equal distances between hills are difficult to determine but it is essential that the estimated distances should not be too close or too wide (not less than 10 cm and not more than 25 cm) to complement control of weeds through early shading by rice canopies.

 

Straight-row Method

This method follows uniform spacing or pattern.

 

traight rows facilitate management practices such as hand or rotary weeding and application of fertilizers, herbicides, or insecticides. Optimal plant spacing may also be achieved through this method.

Transplant 2−3 seedlings of 15−21 days wet-bed or dry-bed grown seedlings at 20 x 20 cm spacing.

Closer spacing (15 x 15 cm or 10 x 10 cm) may be used depending on the availability of planters and the cost of transplanting. This is advantageous when weed control is inadequate.

 

Mechanical transplanting requires considerably less time and labor than manual transplanting. One hectare of land requires 1 person day to establish.

Different type of transplanters with varying levels of complexity and sizes can be used, such as:

• two-row walk behind models
• eight-row ride-on models

The rice field must be well prepared for machine transplanting.

Raise seedlings in special mat nurseries or in seedling trays. Use 18−25 kg of good seed per 100 m² of nursery for each ha. Seedlings will be ready for transplanting in 15−21 days after seeding (DAS).

1. Ensure that fields are well puddled and leveled.
2. Drain fields and allow mud to settle for 1−2 days after the final puddling.
3. The subsurface soil layers need to be hard enough to support the transplanting machine.The soil is ready when a small “V” mark made in the puddled soil with a stick holds its shape. At this moisture level, the soil can hold the seedlings upright.

   Soil should not be so dry that it sticks to and interferes with planting parts or wheels of the transplanter.

4. Load the seedling mats on the machine and transplant the seedlings at the selected machine setting.

 

Preparing the seedlings for transplanting

Prior to transplanting, seedlings need to be raised in a nursery. Seedling nurseries usually use 5−10% of the total farming area.

When choosing the appropriate nursing system, consider the availability of sunlight, water, labour, land, and agricultural implements.

 

Wet beds

Use this method in areas with sufficient water supply. Allot 1/10 of the field for the seed bed area, and prepare 40 kg of seed to transplant 1 ha of land.

• Prepare beds at 1 m wide by convenient length. Raise the soil to 5−10 cm height
• Broadcast pre-germinated seeds in thoroughly puddled and leveled soil.
• Construct drainage canals for proper water removal.
• Add organic manure (decompose) and a small amount of inorganic fertilizer as basal dressing. This increases seed vigor and allows easier uprooting for transplanting.
• Transplant seedlings at 15−21 days old.

 

Dry bed

Prepare the nursery in dry soil conditions. Ensure that the site is free of shade and has access to irrigation facilities. Allot 1/10 of the field for the seed bed area, and prepare 60−80 kg of seed to transplant 1 ha of land.

• Prepare beds at 1 m wide by convenient length. Raise the soil to 5−10 cm in height.
• Distribute a layer of half burned paddy husk on the nursery bed to facilitate uprooting.
• Prevent moisture stress by irrigation. Without appropriate moisture, roots may be damaged during pulling.
• If nutrient supply is low, apply basal fertilizer mixture and incorporate it between rows.
• Transplant seedlings at 15−21 days old.

Seedlings raised in dry-bed are short, strong, and has a longer root system than those raised in wet-beds.

 

Dapog

Dapog or mat method is most appropriate for growing short duration varieties, as seedlings experience less transplanting shock.  Compared to other methods, this requires less labor, and has minimal root damage.

• Prepare dapog nurseries where a flat firm surface is available and water supply is very reliable. Allot 100 m²/ha or 1% of the field for the seedbed, and prepare 40−50 kg of seed per ha.
• Mark out 1 m wide and 10−20 m long plots.
• Cover the surface with banana leaves, plastic sheets, or any flexible material from penetrating the bottom layer of the soil. Cemented floors may also be used as base. Form the boundary with bamboo splits or banana sheath.
• Cover the seedbed with about 1 cm of burned paddy husk or compost.
• Sow pre-germinated seeds on the seedbed. Maintain a thickness of 5−6 seeds (1 kg per 1.5 m²).
• Sprinkle water to the seeds after sowing, and then press down by hand or with a wooden flat board.
• Prevent water stress by irrigation.
• Transplant seedlings at 9−14 days old.

 

The modified mat nursery

The modified mat nursery uses less land and requires fewer seeds and inputs (i.e., fertilizer and water). Allot 100 m²/ha for the seedbed, and prepare 18−25 kg of good quality seeds.

• Cover the surface of 4 cm layer soil mix with banana leaves, plastic sheets, or any flexible material from penetrating the bottom layer of the soil.
• Sow pre-germinated seeds on the seedbed, then sprinkle with water. Maintain a thickness of 2−3 seeds.
• Water the nursery 2 times a day for 5 days.
• Transplant seedlings at 15−21 days old, when seedlings reach the four-leaf stage.

http://www.knowledgebank.irri.org/step-by-step-production/growth/planting/how-to-prepare-the-seedlings-for-transplanting#modified-mat-nursery

 

Insect Pest management

Stem Borers

There are different types of stem borers. Caterpillars that bore into stem cause the damage and feed internally causing the death of central shoot. Affected plants produce white chaffy ear head at flowering stage. Just after hatching larvae migrates between the leaf sheaths where they are protected from natural enemies and insecticidal sprays.

 

Management 

• Plough and destroy the stubbles after harvest, collect and destroy egg masses in nursery plants.
• Clip off the leaf tips and burn to kill eggs or larvae preventing them from carrying into the main field.

Chemical Control 

• Dip the root of seedlings before transplanting in a solution of chlorpyriphos 1 ml in 1 litre of water for four hours.
• Apply carbofuran 3G @ 20-25 kgs per hectare at 20 and 40 days after transplanting. If the pest appears spray the crop with endosulfan (20 ml) or Carbaryl (36gm) or Quinalphos (27ml) in 18 litre water.

Army Worms

A full grown caterpillar is dull green in colour with four longitudinal stripes and an orange or brown head. Caterpillars feed on the leaves and in severe infestation entire seed beds and fields are destroyed and the fields appears as if it has been grazed by animals /cattles. The larvae feed voraciously in the night and hide in the soil during the day time.

Management

• Regular survey of crop at and before maturity. Keep the field under water through proper water management.
• Place straw beds in the fields at several locations. Collect /destroy hiding caterpillars.
• Spray the Bunds with pesticides to prevent migration of pest from one plot to another.

 

Chemical Control

• Spray the crops with any of the chemicals as mentioned in the spray schedule under stem borers.

 

Rice Hispa

The insect has attained the status of major pest in bordering areas of Assam and Bangladesh. Both adults and grubs do damage. The adults are small blue green beetle with spines all over the body. The grubs enter and mine the leaf between the epidermal layers creating irregular translucent patches. The adults scrap the upper surface of the leaf blade leaving only the lower epidermis. The damaged plant parts appear as white streaks parallel to the mid ribs.

 

Management

• Check up at the nursery stage, clip affected leaves to prevent carry over grub population. Remove weeds from the nearby fields, which serve as alternate host of the pest.

 

Chemical Control

• Dip the seedlings in Chlorpyriphos (0.02 %) for 30 minutes before transplanting.
  * Apply Carbofuran 3G @ 20-25 kg per hectare at 20 to 40 days after transplanting. If the pest appear spray the crop with the same chemicals as per spray schedule under stem borers.

 

Leaf Folders

The adult moths are brownish orange in colour 8-10 mm long with a wing span of 12-20mm. The larva infests the leaves, roll them longitudinally, live inside and feed on the green matter.

 

Management

• Remove grasses and weeds from the nearby field which are alternate host of the pest.

 

Chemical Control

• When Infestation is observed spray the crop with the chemicals as recommended earlier.

 

Case Worm

Adults are 6mm long with wing span of 15mm. Slender green coloured caterpillars, cut leaf blades, out of which they make tubular cases with which they feed. Several tubes are seen hanging from the plants. The caterpillars often drop suddenly on the surface of water and paddle along till it reaches another plants. During heavy damage, leaves are skeletonised and appear whitish in colour.

 

Management

• Drain water from the field to flush out the insects and tubular cases floating in the field.

 

 

Chemical Control

• Spray the crop with Quinalphos or Endosulphan solution @ 27ml either one of the chemicals in 18 litres of water.

 

Gundhi Bug

It is a major problem in upland as well as in lowland where paddy is grown continuously. The adult is about 15mm long, slender and brownish green in colour, which emits an offensive odour. Both nymphs and adults suck the sap from the developing grains by which grains becomes empty (chaffy), lower in quality and break during milling.

 

Management

• Use pheromone traps.

 

Chemical Control

• Dust the crop with Carbaryl 5% or Malathion 5% dust or Chlorpyriphos 2% dust @ 20kg/ha in the morning hours with dusters.
• Spray the crop with Monocrotophos or Endosulphan or Quinalphos @ 27ml/18litres water to reduce the population.

 

Plant Hopper

The adult hopper is light to dark brown in colour measuring about 3-4mm in body length. Both nymphs and adults damage the plants by sucking the sap. During the early stage of plant growth reduces height, general vigour and infested plants turn yellow and dries up. At later stages, crop dries up in patches known as hopper burn.

 

Management

• Drain water from the field to flush out the insects and tubular cases floating in the field.
• Clean cultivation by timely weeding to reduce pest population.
• Adopt spacing as recommended.
• Use resistant varieties.

 

 

 

Chemical Control

• Spray the crop with Quinalphos or Endosulphan solution @ 27ml either one of the chemicals in 18 litres of water.

 

Root Knot Nematodes

Those are tiny worms like living bodies. Causes formation of galls on the roots. It attacks the crops during early growth stages and is severe in uplands. The infected plants look stunted with orange yellow leaves and highly reduced yield.

 

Management

• Use resistant varieties.
• Provide staking for perching birds.
• Seed/ Seedlings treatment to reduce field protection.
• Place straw on bunds and in fields at several locations collect/destroy hiding caterpillars.
• Check the nursery, clip off affected leaves if infestation is noticed.

 

Chemical Control

• Apply Carbofuran Granules @ 20-25 Kg in nursery at 7 and 50 days after transplanting help control the destruction by root knot nematodes.

 

I.P.M Strategy for Management of Insect Pest

• Regularly check the insect pest population and its build up.
• Collect egg masses by hand and kill.
• Conserve and encourage parasites and predators.
• Use selective insecticide.
• Clean cultivation-timely weeding.
• Avoid chemical control even at minor loss. Use chemical when only needed.
• Use chemical safe to environment.
• Use balance fertilizers.
• Go for resistance and tolerance varieties.

http://megagriculture.gov.in/PUBLIC/package_of_practice/rice.aspx#manures_fertilizers)

 

Harvesting

Harvesting is the process of collecting the mature rice crop from the field. Paddy harvesting activities include reaping, stacking, handling, threshing, cleaning, and hauling. These can be done individually or a combine harvester can be used to perform the operations simultaneously.

It is important to apply good harvesting methods to be able to maximize grain yield, and minimize grain damage and quality deterioration.

Harvesting rice consists of the basic operations which can be done in individual steps or in combination using a combine harvester. These include:

• Reaping– cutting the mature panicles and straw above ground
• Threshing – separating the paddy grain from the rest of cut crop
• Cleaning– removing immature, unfilled, non-grain material
• Hauling– moving the cut crop to the threshing location
• Field drying– leaving the cut crop in the field and exposing it to the sun for drying (optional)
• Stacking/piling– temporarily storing the harvested crop in stacks or piles (optional)
• Bagging– putting the threshed grain in bags for transport and storage

 

Traditional harvesting activities such as field drying and stacking/piling are not recommended because they can lead to rapid quality deterioration and increased harvest losses.

Besides these, a variety of other activities can be included in harvesting such as gathering, reaping (gathering standing grain by cutting), bundling, and various forms of transporting the crop and grain.

 

 

Various harvesting systems can be observed in different locations. A wide variety of tools may be used such as knives, sickles, animals, stationary threshing machines, tractor-mounted harvesters, and self-propelled combined harvesters.

 

The most common systems for paddy harvesting are:

 

Manual harvesting and threshing
This includes use of traditional tools for harvesting (e.g., sickles, knives) and threshing (e.g., threshing racks, simple treadle threshers and animals for trampling). A pedal thresher is a simple tool to improve manual threshing.

 

Semi-mechanical systems, such as

Manual reaping and mechanical threshing
Manual harvesting is done by hand. The use of portable thresher is usually the first step in mechanical threshing. The use of small stationary machine threshers commonly replaces manual threshing given its high labor requirements. Stationary threshing is generally done in the field, or near the field.

Reaping followed by machine threshing
Cutting and laying the crop on a windrow is done using a reaper, threshing by a thresher, and cleaning either manually or by machine.

 

Combine harvesting
The combine harvester combines all operations: cutting the crop, feeding it into threshing mechanism, threshing, cleaning, and discharge of grain into a bulk wagon or directly into bags. Straw is usually discharged behind the combine in a windrow.

 

Choosing an appropriate harvesting system depends on a number of factors:

• Availability of labor (manual harvesting is labor-intensive)
• Availability of capital to purchase equipment
• Timeliness of harvesting (how much time is available to complete the harvest)
• Field layout and field accessibility (combine harvesters require a certain field layout and access)
• Rice variety (some varieties are more prone to lodging)
• Demand for quality rice
• Demand for straw (certain threshers damage the straw making it less marketable)

 

The steps involved in rice processing are as follows:

 

Cleaning

After harvesting rice, it is transferred to the processing plant where foreign objects and like stones and tree stumps are removed using Destoner

 

Hulling

Next husk is separated from clean paddy. After the husk is removed, the product is called brown rice and is ready for the milling process. Paddy graders and paddy cleaners are used to separate brown rice

 

Milling

This stage removes the bran layer of rice turning brown rice into white rice

 

Polishing

The surface of rice is smoothened and it is given a shine by passing it through a series of rollers

 

Grading

It is a process in which broken rice is separated out and separating head rice into different lengths

 

Sorting

Discoloured, yellow and immature rice is removed in this stage adding value to rice

 

Packing

The finished product is then packed and is stored to be delivered to valued customers. https://www.quora.com/What-steps-are-involed-in-rice-processing

 

 

 

 

http://www.asiafarming.com/wp-content/uploads/2016/04/Rice-Pests-and-Disease.pdf

 

Fertilizer Management

High rates of nitrogen fertilizer will provide more plant nutrition, resulting in higher yield. However, high nitrogen fertilizer rates also: y increase weed populations in the current and subsequent crops y increase the incidence of fungal and bacterial diseases by increasing tissue susceptibility and tiller density and y encourage the multiplication of brown plant-hopper, leaf folders, stem borers, leafhoppers, gall midge, armyworm, root weevil and leaf beetles. Under high nitrogen fertilizer conditions, insects generally grow larger, cause more damage, produce more offspring, grow faster, and complete more generations per crop. The beneficial effect of nitrogen on plant growth outweighs the pest-controlling effects of entirely omitting its use. However, splitting the application, using sensible amounts, and using slow release forms (such as sulphur coated urea and urea super granules) helps to meet the dual goal of higher yields and lower pest incidence. On the other hand, thrips and whorl maggots become less abundant if nitrogenous fertilizer is applied. Phosphorous tends to increase abundance of stem borers, but to a lesser degree than nitrogen. Phosphorous is important in root development, which allows the crop to tolerate weevil damage to its roots. Potassium y suppresses many insect pests—such as the whorl maggot, green leafhopper, yellow stem borer, brown plant-hopper, thrips, and leaf folder—by lowering the level of plant sugars and amino acids y increases production of allele-chemicals, thickening the cell wall and increasing the amount of silica uptake. Silica hardens the rice stem making the crop resistant to feeding by stem borer larva. 8 In summary, sensible and balanced used of fertilizers is important for insect pest management and higher yields.

 

Water management

Pests such as whorl maggots, root feeding midges, water weevils, caseworms, and others are suppressed when fields are drained for 1 or 2 days. This is mainly due to the effect that water absence has on their respiration. The draining of fields is a common practice to suppress plant-hoppers and armyworms. Alternate flooding and draining, if carried out for 5-7 days, can minimize some semi-aquatic insect pests such as black bugs, plant-hoppers, gall midge, hispa, and most stem borers. Draining rice fields 7 can reduce the threat of hopper burn. Draining stimulates calcium uptake, which hardens plant tissues and makes them more resistant to pests. However, draining may also stimulate weed growth. Frequency of action is important because alternative flooding and draining can cause high losses of nitrogen. Pests adapted to dry land—such as armyworms, grasshoppers, thrips, ants, white grubs, mole crickets, root aphids, termites, root weevils, and seedling maggots—are highly vulnerable to flooding.

http://www.knowledgebank.irri.org/ericeproduction/PDF_&_Docs/Control_of_rice_insect_pests.pdf