The main rice growing season in India is Kharif. The sowing time of Kharif rice is June-July and it is harvested in November- December.  Autumn rice is grown in March- April and harvested in June-July.

West Bengal, Uttar Pradesh, Punjab, Tamil Nadu, Andhra Pradesh, Bihar, Chhattisgarh, Odisha, Assam and Haryana are the leading producing states of Rice in India.

Rice is a crop of tropical climate. It is also grown successfully in humid to sub-humid regions under subtropical and temperate climate. Under high temperature, high humidity with sufficient rainfall and irrigation facilities rice can be grown well.

Optimum temperature of 16-30^oC is required with minimum of 100-200 cm rainfall. Sowing temperature should be 20-30^oC and harvesting temperature of 16-27^oC is essential for rice cultivation.

Soil-

Rice is cultivated in almost all types of soil with varying productivity. The major soil groups where rice is grown are riverine alluvium, red loamy, red sandy, shallow black soils. It grows well in soils having pH range of 5.5 and 6.5.

There are four methods for cultivating rice-

1. Broadcasting Method- Broadcasting is the most common and traditional method of sowing seeds. It involves of scattering of seeds by hand over a large area. It is practice in areas which are dry and less fertile in nature. It is the easiest method and requires minimum inputs.
2. Drilling Method- Seed drill is used to sow seed by positioning them and burying them to a specific depth. In this method, the land is ploughed and the sowing of seed is done by two people and is confined to peninsular India.
3. Transplantation Method- In this method, seeds are sown in a nursery and the seedlings are prepared there. After 4-5 weeks in the nursery the seedlings are uprooted and planted in fields. It is a difficult method as everything is done by hand and requires heavy input. It is practiced in areas having fertile soil, abundant rainfall and supply of labour. It provides high yield.
4. Japanese Method- This methods has been successfully adopted by the main rice producing area and is used to obtain high yields. In this method high yielding variants of seeds are used and heavy dose of fertilizers are used. The seeds are sowed in a nursery and they are transplanted in rows so as to make weeding and fertilizing easier.

For hybrid rice seed rate is 6-7kg/acre and for normal variety it is 10-12kg/acre.

Spacing- For normal sown crop spacing of 20-22.5cm between rows is recommend. When sowing is delayed a closer spacing of 15-18cm should be adopted.

Sowing Depth- Seedlings should be planted at a depth of 2-3cm.

Seed Treatment-

Before sowing seed in nursery treat the seed with 4gm streptocycline sulphate per 25 kg seed or use 40 gm plantomycine.  Make solution of 45 L water and dip the seed in it for night, dry it in shade and sow it in nursery to control bacterial blight.

Generally, it is done by making solution of 75 gm thiram or 50 gm carbendazim in 8-10 L of water to treat 25 kg seeds.

Dip the seed in it for few minutes and allow it to germinate before sowing in nursery. Trichoderma @125gm/25 kg seeds can also be used to treat the seeds.

Use lesser land levelling for land levelling. After then puddle soil and to obtained fine well levelled puddled field to reduce water loss through percolation. After summer ploughing, 2-3 ploughing are required to prepare the soil.

Irrigate the field at least one week prior of transplanting to allow to grow weeds. Then plough the field by filling water and do puddling before transplanting.

Keep field flooded upto 2 weeks after transplanting. When water gets filtered, after 2 days apply irrigation in the field. Depth of standing water should not exceed 10cm. While doing intercultural operations drain out excess water from field and irrigate field after completion of these operations. Stop irrigation about a fortnight before maturity to facilitate easy harvesting.

Stage wise water requirement for Paddy-

Critical Stages of Irrigation- The stage at which water stress cause severe yield reduction is known as critical stages of irrigation.

Critical stages of water requirement in Paddy are as follows-

• Active Tillering
• Panicle initiation
• Booting
• Heading
• Flowering

Apply fertilizer based on soil test result-

1. For transplanted puddled Low land rice- N:P:K = 60:20:20 kg/acre

In nursery, before the last puddling apply basal application of DAP (20kg) when seedlings are to be pulled out in 20-25 days after sowing. For clay soils where root snapping is a problem, 2kg of gypsum and 10.5kg of DAP can be applied at 10 DAS.

1. For direct wet seeded puddled lowland rice- N:P:K = 25:12:12 kg/acre.

Apply zinc sulphate heptahydrate @25kg or zinc sulphate monohydrate @16kg/acre at puddling to overcome zinc deficiency.

Use Rotary weeder from 15 DAT at 10 days interval to overcome weeds in paddy field.

Use pre-emergence herbicide- Butachlor 50 EC @1200ml/acre

Pose- emergence herbicide- Fenoxaprop 6.7% @350ml/acre

For broad leaf weeds use Metsulfron 20 WP @30gm/acre in 150 L water as post-emergence, 20-25 days after transplanting.

 1. Paddy Stem Borer-

Symptoms of damage-

• Presence of brown colored egg mass near the leaf tip.
• Causes drying of the central shoot known as “Dead hearts”
• Whole ear heads become dried and yield chaffy grains called as “White Ear”

Management-

• Avoid Close Planting and continuous water Stagnation at early stages. Pull out and destroy the affected tillers.
• Spray any of the following insecticides-

Monocrotophos 36SL @1000ml/ha or Fipronil 5% SC @25-30ml/pump.

2. Fall Armyworm-

Symptoms-

• Damage is caused by Larvae, larvae feeds on young rice seedlings, destroying large amount of plant tissues.
• Larvae cut the seedlings in large scale.
• They cut off rice panicles from base.
• Armyworm feeds on leaf tips and leaf margins.
• Scrapping of leaf surface by young larvae
• Older leaves, feeds upon central whorl causing extensive defoliation.

Management-

• Seed treatment with Thiamethoxam 19.8% FS @6ml/kg of seeds
• Maintain field sanitation, clean the weeds and destroy the infected plants
• Foliar spray of Emamectin Benzoate 5SG @0.5gm/L of water

3. Rice Leaf Folders-

Symptoms-

• Leaf folders fold a rice leaf around themselves and attach the leaf margins together with silk strands.
• Longitudinal and whitish streaks on damaged leaves
• Heavily infested fields appear scorched with many folded leaves.
• Larva feeds the green tissue of the leaves, which later becomes white and gray
• The leaves of the plant are seen folded, rolled and often webbed together with white patches on them indicating the areas by caterpillar.

Management-

• Use disease resistant varieties
• Keep the bunds clean by trimming them and remove the grassy weeds.
• Avoid use of excessive nitrogenous fertilizers
• Avoid rattooning
• Application of following insecticides-

Flubendiamide 20%WG @1gm/L of water

Emamectin Benzoate 5% SG @1gm/L of water

Chlorpyriphos 50%SC @2ml/L of water

4. Rice Bugs-

Symptoms-

• Nymphs and adult suck the sap from individual grains which are in milky stage.
• Individual grains become chaffy
• Black spots on the grains at the site of feeding puncture
• Buggy odour in the rice field during milky stage.
• Feeding can result in empty grains or deformed grains
• Panicles appear erect

Management-

• Remove alternate host
• Remove weeds from the field
• Apply a balanced fertilizer dose
• Water regularly but avoid excessive humidity
• Spray aromatic soap solution (Lemongrass) to expel the rice bug
• Application of fipronil @2ml/L of water

5. Weevils-

Symptoms-

• Both grub and adult causes damage
• The primary damage caused by rice weevils is to the rice kernels.
• Infested kernels may have small holes where the weevils have entered or exited. The kernels may also appear hollowed out or chewed.
• Infested grains can lead to reduce grain quality.
• Secondary issue such as fungal growth can occur in the presence of weevil damage, as the holes created by the weevils allow for the entry of moisture and pathogens.

Management-

• Application of cypermethrin 25% EC@30-40ml/15 L of water
• Use resistant varieties
• Ensure rice is properly dried to the recommended moisture content should be below 14% before storage to minimize weevil infestation.
• Regularly clean and sanitize equipment and storage areas to remove any weevils or infested grains.

6. Thrips-

Symptoms-

• Feeding damages caused by thrips includes curling of leaves and discoloration.
• Damaged leaves may have silvery streaks or yellowish patches.
• Leaves curled from the margin to the midrib
• Unfilled grains at the panicle stage
• Plants become stunted
• Leaves crinkle drop

Management-

• Use resistant varieties
• Flood the rice field for 1-2 days will kill many of the thrips.
• Application of the following insecticide

Imdiacloprid 17.8%SL @40ml/acre

Chloripyriphos 50% + Cypermethrin 5% EC @30ml/Pump

7. Brown Plant Hopper-

Symptoms-

• Yellowing, browning and drying of the plant
• Circular patches of drying and lodging of matured plant
• Nymphs and adults congregate at the base of the plant above the water level

Management-

• Draining the rice field for 3-4 days is recommended during early stage of infestation.
• Nitrogen application can be split to reduce Brown Plant Hopper buildup.
• Spray Lambda Cyhalothrin 5% EC @20-25ml/pump or Imdiacloprid 30.5% EC @5-6ml/pump

8. Yellow Hairy Caterpillar-

Symptoms-

• Caterpillar causes defoliation
• Larva feeds on leaf blades of rice
• Leaves are defoliated from the margin or tip irregularly

Management-

• Spray the crop with Chloripyriphos 50%EC @400ml/acre
• Remove and destroy infested plant parts to reduce caterpillar populations.
• Encourage the presence of natural predators such as birds, parasitoid wasps, and predatory beetles.
• Incorporate Bacillus thurigiensis, as this bacterial pesticide is effective against caterpillars, it should be applied to the leaves of infested plants where caterpillars feed.
• Light traps can attract and capture adult moths, reducing the number of eggs laid on plants.
• Regularly inspect plants for signs of caterpillars and their damage.
• Rotate crops to reduce the likelihood of repeated infestations.

9. Gall Midge-

Symptoms-

• Tillers turn into gall and dry, looks silver shoot.
• Causes elongation of leaf shoots called onion shoot or silver shoot.
• Infected plants fail to produce panicle
• Deformed, wilted and rolled leaf
• Stunted growth of plant

Management-

• Spray Thiamethoxam 25% WG @0.5gm/L of water
• Plant resistant varieties
• Remove off season plant host
• Draining out water from paddy fields for 5-7 days will drastically bring down gall midge population.
• Set up light traps @1/acre
• Collect and destroy all the infested plant debris

10. Mealy Bugs-

Symptoms –

• Large number of insects remains in leaf sheath and suck the sap.
• Plants become weak, yellowish and very much stunted in circular patches.
• Leafs started to curl and wilt

Management-

• Remove the grass and trim the bunds during the main field preparation before transplanting.
• Remove and destroy the affected plants from the field
• Application of following insecticides-

Profenofos 50% EC @500-800ml/acre

Monocrotophos 36% SL @3.5ml/L of water

11. Green Leafhopper-

Symptoms-

• Green leaf hopper can spread Rice Tungro virus
• Both nymphs and adult feed by extracting plant sap with their needle shaped mouth parts.
• Stunted plant and reduce plant vigor
• Reduced number of productive tillers
• Withering and complete plant drying

Management-

• Use GLH and Tungro disease resistant varieties.
• Avoid planting during the peak of GLH Growth
• Apply nitrogen as needed do not overdose nitrogenous dosage
• Maintain field sanitation
• Application of Carbofuran 3G @5gm/L of water

1. Blast-

Causal Organism- Pyricularia oryzae

Symptoms-

• Small specks originate on leaves- subsequently enlarge into spindle shape spots (0.5 to 1.5cm) length, 0.3 to 0.5cm width with ashy center.
• Initial symptoms appear as white to gray lesions or spots, with dark green borders.
• Some symptoms may resemble diamond shape, wide in center and pointed towards either ends.
• Lesions can enlarge and coalesce, growing together, to kill the entire leaves.
• All above ground parts of the plants are attacked by the fungus.
• Nodal infection causes the culm to break at the infected node.
• Internodal infection also occurs at the base of the plant which causes white panicles similar to that induced by yellow stem borer or water deficient.
• If infection of the neck occurs before milk stage, no grain is formed, but if infection occurs later, grains of poor quality are formed.

Management-

• Spray Azoxystrobin 23% SC @15ml/pump or Tricyclazole @16gm/pump

2. Bacterial Leaf Blight-

Causal Organism- Xanthomonas oryzae

Symptoms-

• Lesions are elliptical and tan in color, developing distinct dark areas as they mature that are associated with fungal sporulation.
• Lesions appear first appear on lower leaves, spreading to upper leaves and the ear sheath as the crop mature.
• Under severe infection, lesions may coalesce, blighting the entire leaf.
• Green water soaked layer along the cut portion or leaf tip
• In severe infestation, entire plant wilt completely.

Management-

• Soak the seeds with a solution of Streptomycin @1.5gm or copper oxychloride @25gm/ 10 L of water.
• Use fresh cow dung slurry at 2kg/10L of water, strain it in fine cloth and spray at an interval of 7-10 days 3-4 times @250L/acre.

3. Brown Leaf Spot-

Causal Organism- Helminthosporium oryzae

Symptoms-

• Infected seedlings have small, circular, yellow brown or brown lesions that may girdle the coleoptile and distort primary and secondary leaves.
• Starting at tillering stage, lesions can be observed on the leaves. They are initially small, circular and dark brown to purple-brown.
• Fully developed lesions are circular to oval with a light brown to gray center, surrounded by a reddish brown margin caused by the toxin produced by the fungi.
• Infection also occurs on panicle, neck with brown color appearance
• 50% yield reduces due to infection

Management-

• Seed treatment with Captan or Thiram @2gm/kg of seeds
• Spraying of Tricyclazole followed by spraying of mancozeb + Tricyclazole at tillering and late booting stages give good control of disease.
• Use Propineb 70% WP @400gm/acre

4. False Smut-

Causal Organism- Ustilaginoidea virens

Symptoms-

• Rice grain transformed into a mass of yellow fruiting bodies.
• Mature spores orange and turn yellowish green or greenish black.
• Growth of velvety spores that enclose floral parts
• Infected grain has greenish smut balls with a velvety appearance.
• The smut ball appears small at first and grows gradually up to the size of 1cm
• It is seen in between the hulls and encloses the floral parts

Management-

• Spraying of Propiconazole 25EC @250ml/acre
• Application of copper hydroxide 77WP @500gm/acre

5. Sheath Blight-

Causal Organism- Rhizoctonia solani

Symptoms-

• The fungus affects the crop from tillering to head stage
• Irregular greenish small oval spots can be seen on leaf surface
• As the spots enlarge, center becomes greyish white with an irregular blackish brown or purple border.
• In severe infestation, plants may wilt or die off
• Older plants are highly susceptible.

Management-

• Seed treatment with Pseudomonas fluorescens @10gm/kg of seeds
• Avoid excess dose of nitrogenous fertilizers
• Adopt optimum spacing
• Maintain field sanitation, clean all the weeds from the field.
• Application of Carbendazim @1gm/L of water or Propiconazole @1ml/L of water

6. Rice Tungro Virus-

Causal Organism- It is fungal disease caused by 2 viruses namely, Rice Tungro Bacilliform Virus (RTBV) and Rice Tungro Spherical Virus (RTSV)

Symptoms-

• Infected plants shows stunting and wilting symptoms
• Leaves become yellow or orange yellow, it may also have rust colored spots
• Yellowing starts from tip of the leaf, and may extend to lower part of the leaf blade.
• Delayed flowering panicles are small

Management-

• Set up light traps to attract and control leaf hopper vector
• Planting disease resistant varieties
• Adjust the date of planting
• Leaf yellowing can be minimize by mixing 2% Urea mixed with mancozeb @2gm/L of water

7. Khaira Disease-

Caused by- Khaira disease is caused due to Zinc Deficiency

Symptoms-

• Formation of dusty brown patches on leaves and leads to necrosis
• Yellowing of young leaves, between veins, while the veins themselves remain green.
• Overall growth and dwarfism in affected plants.
• Poor root development and sometimes the roots appear brownish.
• Presence of small white or brown spots on the leaves, which can coalesce to form larger patches.
• Affected plants often show delayed maturity and reduced grain yield.

 Management-

• Apply Zinc Sulfate (ZnSO₄) @ 25-50kg/ha as a basal application during land preparation.
• Foliar spray of 0.5% Zinc Sulfate solution @5gm/L of water can be applied at the early stages of deficiency.
• Maintain proper water levels in fields, as excessive water can exacerbate zinc deficiency.
• Ensure good drainage to avoid waterlogging.
• Apply organic matter like compost or farmyard manure to improve soil structure and zinc availability.
• Incorporate lime or gypsum if the soil pH is highly acidic or alkaline to improve zinc uptake.

8. Sheath Rot-

Causal Organism- Sarocladium oryzae

Symptoms-

• Panicles rot and grains become discolored
• It appears oblong or as irregular spot with dark reddish, brown margins and gray center or brownish gray.
• Affected leaf sheath have white powdery fungal growth visible on the outer surface.

Management-

• Seed treatment with Bacillus subtilis @10g/kg of seeds
• Removal of infected debris after harvesting
• Optimum plant spacing can reduce the disease
• Maintain field sanitation

9. Brown Spot-

Causal Organism- Bipolaris oryzae

Symptoms-

• Brown spot is a fungal disease that attacks leaves, leaf sheath and panicle branches, glumes and spikelets.
• Infected seedlings have small, circular yellow or yellow brown lesions that may girdle the coleoptile and distort the primary and secondary leaves.
• Starting at tillering stage lesions can be observed on the leaves. They are initially small, circular and dark brown to purple-brown.

Management-

• Use resistant varieties
• Seed treatment with Carbendazim @4gm/kg of seeds
• Treat seeds with hot water for 10-12 minutes before planting to control primary infection at the seedling stage.
• Foliar spray of Mancozeb @2gm/L of water 2-3 times at 10-15 days of interval.

10. Leaf Streak-

Causal Organism- Xanthomonas oryzae

Symptoms-

• Symptoms are seen as narrow-dark greenish, water soaked interveinal streaks of various length on the leaf blades.
• The lesions enlarge and turn to yellow-orange to brown in color.
• The lesions are translucent when held against the light.
• In Severe infestation, entire leaves may die

Management-

• Treat seeds with hot water before sowing
• Remove weeds and maintain field sanitation
• Use balanced amount of plant nutrients
• Remove and destroy infected plants from the field
• Provide good drainage system
• Plant resistant varieties
• Spraying streptomycin sulphate and tetracycline combination 300gm+ Copper oxychloride @1.25kg/ha

Taking the average duration of the crop as an indication, drain the water from the field 7 to 10 days before the expected harvest as draining hastens maturity and improves harvesting conditions.

When 80% panicles turn straw color, the crop is ready for harvest. Even at this stage, the leaves of some of the varieties remain green.

Confirm maturity by selecting the most mature tiller and dehusk a few grains.

When most of the grains at the base of the panicle in the selected tiller are in hard dough stage, the crop is ready for harvest. At this stage harvest the crop, thresh and winnow the grains.

Dry the grains to 12% moisture level for storage. Grain yield in rice is estimated only at 14% moisture for any comparison. Maturity may be hastened by 3-4 days by spraying 20% NaCl a week before harvest to escape monsoon rains.

Yield depends upon the variety used and agronomic practices but generally, average yield of rice is about 25-30 Quintal/acre, However, it can go upto 50-60 quintal for hybrid seeds.