PADDY PACKAGE OF PRACTICES

Scientific name: Oryza sativa

Common name: Paddy

Telugu name: Vari

Introduction:

Paddy is one of the most important staple crop feeding billions globally. It is also cultivated on a large scale in India and in states like Telangana, Andhrapradesh, West Bengal, Punjab. Growing paddy ivolves several cultural practices like puddling, Nursery bed preparation, seed treatment, sowing , Transplanting, Irrigation management, controlling weeds, Disesae and pest management. So,it is important to have knowledge on different practices followed in paddy right method and right time to follow them. This  article give information on essential steps to follow in paddy for efficient and sustainable  production.

Climatic requirements:

In India rice is grown under widely varying conditions of altitude and climate. Rice crop generally needs hot and humid climate. The average temperature requirement throughout the life period of the crop ranges between 21 to 37oC. At the time of tillering the crop requires slightly higher temperature. Temperature requirement for blooming is in the range of 26.5 and 29.5oC and ripening time temperature between 20 and 25oC. 

Soil:

Rice can be grown under any type of soil reaction varying from acidic to alkaline. Soil having good water retention capacity with good amount of clay and organic matter is ideal. Well-drained, loamy and light alluvial soils with pH 5.0 to 6.5 are most suitable for proper growth and productivity.

Land Preparation:

Ploughing should start with first shower of monsoon to a depth of 15 cm with the help of power tiller or mould board plough. Apply well decomposed FYM (10 MT) after the first ploughing. This operation is to be completed atleast 15 days before sowing of the seed. Green manures (finely chopped) like Glyricidia (grown on bunds /fences), Dhaincha etc. or any biomass from major weeds on uplands like Eupatorium be incorporated as per availability. Proper leveling and bunding should be ensured for better water and soil conservation.

Nursery seed bed preparation:

Wet method: 

The wet method can be adopted in areas where water is available. Prepare raised beds of 5-10 cm height, 1-1.5 m width and of convenient length with drainage channels between the beds. Total seedbed area should be 1000 m2 for planting in 1 ha. Apply vermicompost @ 500g / m2 and rice husk ash @ 100 g /m2 of the nursery bed and mix well with the soil at the time of preparation of the field. Application of vermicompost reduces the incidence of thrips. If vermicompost is not available, apply compost or cattle manure @ 1 kg /m2 and 100 g of rice husk ash/m2 of the nursery bed and mix well with the soil at the time of preparation of the field. Biofertilizers can also mixed with FYM/ compost before application to nursery @ 2kg/1000 m2.

Dry method:

This method is practiced in areas where sufficient water is not available and the time of planting is uncertain. Prepare raised beds of 1-1.5 m width 15 cm height and of convenient length. Apply vermicompost @ 500 g/ m2 and rice husk ash @ 100 g/m2 of the nursery bed. If vermicompost is not available, apply compost or cattle manure @ 1 kg / m2 and 100 g of rice husk ash /m2 of the nursery bed and mix well with the soil at the time of preparation of the field. Sow the seeds treated as described under dry seed treatment method, evenly over the bed and cover with fine sand / soil.

Dapog Nursery:

Dapog method of raising nursery consists of growing seedlings on raised soil bed covered with polyethelene sheets.To establish a healthy paddy planting, sow pre-germinated seeds on top of the nursery cover, with a recommended rate of one kg per sq. meter.A nursery area of 25 to 35 sq.m. of the area is enough to raise seedlings for 1 hectare.Seedlings raised by this method get ready for transplanting within 13 to 14 days.In case of zinc deficiency, a 0.5% solution of zinc sulphate heptahydrate should be sprayed.

Seed rate: 

1. Transplanting: For medium to fine type rice variety a seed rate of 35-40 kg/ha and for bold type 40-50 kg/ha will be sufficient for transplanting one hectare of land. 

2. Direct seeding: For direct seeding in upland condition, a seed rate of 60-80 kg/ha is required to get good plant stand. 

3. System of Rice Intensification: 5 kg/ha

4. Integrated Crop Management: 10 kg/ha

Time of transplanting/sowing:

Transplanting: The optimum time of transplanting is first fortnight of July for low and mid altitude. Time of transplanting should be adjusted to avoid low temperature during flowering especially in higher altitudes (above 1300 m). Therefore, under high altitude, transplanting should be completed within 15th June, preferably by first week of June. For mid and low altitude valley land, transplanting can be done as late as 3rd week of July with closer spacing (15 x 10 cm) and aged seedling (40-45 days old). Seedling age of 20 -25 days with 20 x 15cm spacing and 2-3 seedlings/hill is considered best for timely transplanted crop. For SRI, 10-12 days and for ICM 15-20 days old seedlings are transplanted. For SRI and ICM methods of rice cultivation only 1 and 2 seedlings and transplanted/hill, respectively with a spacing of 25 x 25 cm for SRI and 20 x 20 cm for ICM.

Direct sown: In upland direct sown crops, sowing should be completed within first fortnight of June in mid altitude condition. Timely sowing is necessary to have enough time for the succeeding rabi crops, which are normally sown in the second fortnight of October. Direct seeded crop is sown in line of 25-30 cm apart maintaining a seed rate of 60-80 kg.

Seed Treatment in Paddy:

Treat paddy seeds using Bavistin Fungicide (Carbendazim 50% WP) at the rate of 2 gm/kg seed for 24 hours to control seed-borne diseases.

Sowing:

Direct seeding either by dibbling of seeds in dry soil at 20 X 15 cm spacing or plough sole placement before onset of regular monsoon is recommended.

Pre-germinated seeds can be broadcasted on a level surface after puddling and maintain a thin film of water.

In a transplanted crop, the seedlings need to be planted at the age of 21-25 days on a puddle soil with 3-4 seedlings/ hill at a spacing of 20 x 10 cm ensuring atleast 50 hills / sq.m. Shallow transplanting favours more tillering and consequently higher yield.

Water Management:

Transplanted rice: Continuous submergence of 2-5 cm during crop growth (transplanting to maturity) gave higher yield. This practice help to suppress weed growth right from the beginning. Water is drained out during fertilizer application. The depth of water should not exceed 5 cm in the field particularly at the tillering stage of the crop. Higher depth of water during tillering reduces the number of tillers/ hill causing reduction in yield. After the completion of tillering, the field should be drained out for a week and reflooded again. This will result in higher number of effective tillers/hill. In any case, there should not be any water stress during panicle initiation to grain filling stage. Irrigation should be stopped 3-4 weeks before harvesting the crop. Under SRI practice no flooding is needed and field is kept saturated. No standing water to be maintained during tillering up to panicle initiation. Intermittent wetting and drying until panicle initiation stage is desirable. The period of drying and wetting can range from 2-7 days.

Weed Management:

Weed control practices includes hand weeding, crop rotation, land leveling, stale seed bed preparation, flooding and use of rotary weeder etc. Longer crop rotation breaks the cycle of weed growth, while proper land preparation, leveling and flooding to uniform depth, suppress weeds directly. In upland rice intercropping with legumes like soybean, groundnut etc. (4:2 row ratio) was found to reduce weed problem besides adding to soil fertility.

• Any pre emergence herbicide has to be mixed with 50 kg of dry sand on the day of application (3 - 4 DAT) and applied uniformly to the field with thin film water on 3rd DAT. Water should not be drained for next 2 days from the field (or) fresh irrigation should not be given.
• Post emergence application (POE) of 2,4-D sodium salt 1.25 kg/ha on three weeks after transplanting.

Nutrient Management:

Nutrient Deficiency and Its Management

Nitrogen:

Deficiency symptoms:

• Yellowing of older leaves first in V shape
• Whole plants yellowish green
• In case of severe deficiency leaves become light green and chlorotic at the tip
• leaves die under severe N stress
• N deficiency often occurs at critical growth stages such as tillering and panicle initiation when the demand for N is large.

Management:

• Divide N fertilizer recommendations larger than 60 kg N/ha into 2-3 (wet- season crop) or 3-4 (dry-season crop) split applications.
• Use more splits, especially with long- duration varieties and in the dry season when crop yield potential is greater.
• Apply top dressing of nitrogen when values of SPAD and leaf color chart goes below 35 and 4, respectively.

Phosporous:

Deficiency symptoms:

• Deficiency symptoms first appear on older leaves, they show characteristic reddish purple color and bluish green color.
• Premature leaf fall.
• Deficiency of phosphorus reduces tillering in rice.
• Develops necrotic area on the leaf petiole.

Management:

• Before transplanting 60 kg P205 is advocated as a basal dose.
• For immediate management of P deficiency in rice water soluble fertilizers like single superphosphate should be applied based on severity of deficiency.
• Growing of green manures or application of FYM @ 15-20 t/ha repeatedly for several years may meet out the phosphorus requirement In case of acute P deficiency as in hills, application of Rock Phosphate @ 5q/ha once in three years may take care of phosphorus nutrition of the organic rice in addition to application of FYM.

Potassium:

Deficiency symptoms:

• Deficiency symptoms of potassium deficiency first occurs on older leaves as dark green plants with yellowish brown leaf margin.
• Deficiency symptoms appear in inverted V shape.
• Necrotic spots appear on the tip of older leaves

Management:

• To avoid potassium deficiency, apply 60 kg K20 before transplanting or direct seeding of rice and mix it well. Soil application of 25% excess of recommended dose of potassium.
• Foliar spray of 1% KCI (Potassium chloride) solution.

Zinc:

Deficiency symptoms:

• Zinc deficiency is not common in acid soils of coastal region but it can be observed in saline situations.
• Zinc deficiency symptom in rice is known as “Khaira disease” brown blotches and streaks appear on lower leaves
• Chlorotic midribs, particularly near the leaf base of younger leaves.
• Dusty brown spots on upper leaves of stunted plants.

Management:

• Apply zinc fertilizer ZnSO4 @ 25 kg/ha at the time of transplanting.
• Foliar spray of 0.5% ZnSO4 when deficiency symptoms start to become visible.

Iron:

Deficiency symptoms:

• Iron deficiency is not common in acid soils of coastal region but it can be observed in saline situations. It is also prevalent in direct seeded rice or aerobic rice.
• Interveinal yellowing and chlorosis is observed on young and emerging leaves.
• Whole leaves become chlorotic and appears pale yellow.
• Entire plant becomes chlorotic and dies if deficiency is very severe.

Management:

• Apply FeSO4 (about 30 kg Fe ha-1) in rows or broadcast.
• Foliar applications of 2-3% solution of FeSO4 or Fe chelates.

Plant protection:

1. Yellow stem borer:

Scientific Name: Scirpophaga incertulas

Symptoms:

• "Dead-heart" at vegetative stage which turns brownish, curls and dries off
• "White ears" at heading stage with empty, partially filled grains
• Presence of egg masses near the tips of tender leaf blades
• Activity of moths in the surrounding area.
• Yellowish white patches on leaf sheath.
• Tiny holes on the stem.

Management:

• Harvesting of crop close to soil surface, ploughing or flooding the field after harvest to kill hibernating larvae in the stubbles.
• Selection of varieties resistant to yellow stem borer: Swarnamukhi (NLR 145),Pothana (WGL 22245), Varsha (RDR 355)
• Clipping the tips of the seedlings prior to transplantation aids in the elimination of egg masses.
• Seedling root-dip with chlorpyriphos (0.02%) @ 200 ml in 200 litres of water in a plot of 3 m x 3 m for 12-14 hours. Seedling root-dip is effective for 30 days in the main field against stem borer, gall midge, BPH and GLH.
• Setting light traps or pheromone traps for monitoring the pest.
• Collection and elimination of egg masses.
• Encouraging natural enemies

Egg parasitoids:

         Tetrastichus schoenobil, Telenomus Trichogramma chilonis, T.japonicum, beneficiens,

Larval parasitoids: 

          Goniozus indicus, Apanteles ruficrus, A. schoenobil, Bracon chinensis

Pupal parasitoids: 

          Elasmus albopictus, Tetrastichus ayyari, Xanthopimpla emaculata

Predator: a carabid, Chlaenius sp.

• Economic threshold levels (ETL)

      Nursery: 1 egg mass or 1 moth/m²

Main crop:

            1 egg mass or 1 moth/m²,5% dead hearts

            1% white ears

• Need based application of insecticides on ETL basis.
• For effective control of stemborer use Biopesticide “LARVEX”@250ml/acre.

2. Brown plant hopper:

   Scientific name: Nilaparvata lugens

Symptoms:

• Premature yellowing of leaves and drying of plants in isolated circular patches.
• Drying of plants spreads in a circular fashion.
• Sooty mould.
• Exuviae at the base of plants.
• Affected stems become soft and are unfit for use as straw.

Management:

• Follow alley cropping.
• Formation of alleys or pathways of 20 cm width for every 2 metres of planting.
• Use resistant varieties like Godavari(MTU 1032),Indra(MTU 1061),Vijetha (MTU 1001),Cottondora sannalu(MTU 1010).
• Do not use excess nitrogenous fertilizer.
• Alternate wetting & drying to avoid water stagnation.
• Avoid methyl parathion 50EC & pyrathroids to prevent resurgence.
• Conserve natural enemies like spiders, mirid bug etc.
• For effective control of Brown plant hopper ,we can use Biopesticide “Dr. ELIMINATOR”@250ml/acre.

Disease Management:

1. Rice blast:

    Casual organism: Pyricularia oryzae

Symptoms:

• This disease causes blue spots on leaves.
• It comes in various forms such as leaf blast,node blast and neck blast.
• The affected areas turn brownish-black and may rot, causing grain damage. 'Neck rot' refers to the rotting of the plant's neck due to this disease.
• 'Node rot' affects the nodes, leading to plant breakage.
• Additionally, creates it greyish- brown spots on the lower parts of the plant. Leaf blast results in ash-gray centers with brown-edged spots on the leaves and can even damage the flowering part.
• This disease weakens the plant's structure, leading to reduced grain production and potential crop loss.

Survival and mode of spread:

• The fungus survives on collateral hosts viz., Panicum repens, Digitaria magrginata, Brachiaria mutica, Leersia hexandra and Echinochloa crusgalli.
• Mycelium and conidia in the collateral hosts, straw and seeds are major sources of primary inoculurn.
• The secondary spread takes place through airborne conidia since spores of the fungus present throughout the year. Irrigation water may carry the conidia to different fields.

Favourable Conditions:

• Intermittent drizzles.
• High relative humidity (93-99 per cent).
• Cloudy weather.
• Low night temperature (between 15-20℃ or less than 26 ℃)
• Availability of collateral hosts.
• Application of excess nitrogen.

Management:

• Use of seeds from disease free crop.
• Grow resistant varieties like  Simhapuri,Tikkana, Sriranga, Phalguna, Swarnamukhi, Jaya, Vijaya, Ratna, MTU-1005, MTU-3&5.
• Remove and destroy the weed hosts in the field bunds and channels.
• Split application of nitrogen and judicious application of nitrogenous fertilizers.
• Treat the seeds with Captam or Thiram @2g/kg.
• Seed treatment with biocontrol agent Trichoderma viridae @ 4g/kg or Pseudomonas flourescens @10g/kg seed.
• Avoid close spacing of seedlings in the main field.

2. Bacterial leaf blight:

Casual Organism: Xanthomonas oryzae pv.oryzae

Symptoms:

• Bacterial blight syndrome exhibits three types of symptoms: leaf blight, kresek  (the seedling blight or wilt phase) and the pale yellow leaf.
• The disease has been referred to as "bacterial leaf blight to indicate that the "leaf blight" phase of the syndrome is the most distinct andcommonly observed symptom.
• Seedlings in the nursery show circular, yellow spots in the margin, that enlarge, coalesce leading to drying of foliage.
• "Kresek" symptom is seen in seedlings, 1-2 weeks after transplanting.
• The bacteria enter through the cut wounds in the leaf tips, become systemic and cause death of entire seedling. In grown up plants water soaked, translucent lesions appear near the leal margin.
• The lesions enlarge both in length and width with a wavy margin and turn straw yellow within a few days, covering the entire leaf.
• As the disease advances, the lesions cover the entire lamina which turns white or straw coloured.
• Milky or opaque dew drops containing bacterial masses are formed on young lesions in the early morning.
• They dry up on the surface leaving a white encrustation.
• If the cut end of leaf is dipped in water, it becomes turbid because of bacterial ooze.
• The affected grains have discoloured spots.

Pathogen Character:

• The bactenum is aerobic, gram negative, non spore forming, rod with size ranging from 1-2 x 0.8-1.0m with monotrichous polar flagellum.
• Bacterial colonies are circular, convex with entire margins, whitish yellow to straw yellow colored and opaque.

Favourable conditions/Epidemiology:

• Clipping of tip of the seedling at the time of transplanting.
• Heavy rain, heavy dew, flooding, deep irrigation water.
• Severe wind and terrmperature of 25-30°C.
• Application of excessive nitrogen, especially late top dressing

Mode of spread and survival:

• The pathogen survives in soil and in the infected stubbles and on collateral hosts Leersia spp., Plantago najor, Paspalum dictum, and Cyanodon dactylon.
• The pathogen spreads through irrigation water and also through rain storm.

Management:

Cultural methods:

• Burn the stubbles.
• Avoid clipping of tip of seedling at the time of transplanting.
• Use optimum dose of fertilizers.
• Remove weed hosts periodically.

Chemical Methods:

• Avoid clipping of leaf tips during transplantation.

Harvesting:

• Rice attains maturity at around 30 days for early and 40 days for medium to late 
• maturing varieties after 50% heading in low and mid altitude areas. In high altitude 
• areas, it may take some more time to attain maturity. Harvesting is done at the yellow 
• ripening stage to avoid shattering loss in field. SRI rice matures 12-15 days earlier than 
• conventional and 7-10 days than ICM. 

Yield: 

A well-managed direct seeded crop yields about 2.5-3.0 t/ha and transplanted crop 

gives about 4.5 -5.0 t/ha under organic production.