Blast - Pyricularia grisea (P. oryzae)
Bacterial Leaf Blight - Xanthomonas oryzae pv.oryzae
Rice tungro disease - Rice tungro virus (RTSV, RTBV)

Brown Spot - Helminthosporium oryzae
Sheath Rot - Sarocladium oryzae
Sheath Blight - Rhizoctonia Solani
False Smut - Ustilaginoidea virens
Grain discolouration - fungal complex
Leaf streak - Xanthomonas oryzae pv. oryzicola

• Earliest known plant disease
• Also known as rotten neck or rice fever.
• Reported from 80 rice-growing countries. First recorded in India during 1918.
• Expected grain loss : 70 to 80%

• Disease can infect paddy at all growth stages and all aerial parts of plant (Leaf, neck and node).
• Among the three leaves and neck infections are more severe.
• Small specks originate on leaves - subsequently enlarge into spindle shaped spots(0.5 to 1.5cm length, 0.3 to 0.5cm width) with ashy center.
• Several spots coalesce -> big irregular patches

Leaf Blast :

• Severe cases of infection - entire crop give a blasted or burnt appearance- hence the name "BLAST"
• Severe cases - lodging of crop (after ear emergence)

Neck Blast

• Neck region of panicle develops a black color and shrivels completely / partially grain set inhibited, panicle breaks at the neck and hangs

Nodal Blast: Nodes become black and break up

• Remove collateral weed hosts from bunds and channels
• Use only disease free seedlings
• Avoid excess nitrogen
• Apply N in three split doses (50% basal, 25% in tillering phase and 25% N in panicle initiation stage)
• Use resistant variety CO 47.
  
  

• Spray after observing initial infection of the disease,
• Carbendazim 50WP @ 500g/ha (or)
• Tricyclozole 75 WP @ 500g/ha (or)
• Metominostrobin 20 SC @ 500ml/ha (or) 47
• Azoxystrobin 25 SC @ 500 ml/ha

Light infection - Spray Carbendazim

Light at 2 to 5 % disease severities - Apply Carbendazim @ 0.1 %. Delay top dressing of N fertilizers when infection is seen. Panicle
initiation to booting

At 2 to 5% leaf area damage spray Carbendazim or Tricyclazole @ 0.1 %.

At 5 % leaf area damage or 1 to 2 % neck infection spray Carbendazim or Tricyclazole @ 1 g /lit of water.  

• Seedling wilt or kresek
• Water-soaked to yellowish stripes on leaf blades or starting at leaf tips then later increase in lengthand width with a wavy margin
• Appearance of bacterial ooze that looks like a milky or opaque dewdrop on young lesions early in the morning
• Lessions turn yellow to white as the disease advances
• If the cuts end of leaf is kept in water it becomes turbid because of bacterial ooze
  

• Spray fresh cowdung extract 20% twice (starting from initial appearance of the disease and another at fortnightly interval)
• Neem oil 60 EC 3% (or) NSKE 5% is recommended for the control of sheath rot, sheath blight, grain discolouration and bacterial blight
  

• Plants affected by tungro exhibit stunting and reduced tillering. Their leaves become yellow or orange-yellow, may also have rust-colored spots.
• Discoloration begins from leaf tip and extends down to the blade or the lower leaf portion
• Delayed flowering, - panicles small and not completely exerted
• Most panicles sterile or partially filled grains
  
  

Physical Method

• Light traps are to be set up to attract and control the leaf hopper vectors as well as to monitor the population.
• In the early morning, the population of leafhopper alighting near the light trap should be killed by spraying/dusting the insecticides. This should be practiced every day.
• Spray Two rounds of any one of the following insecticides
• Thiamethoxam 25 WDG 100g/ha
• Imidacloprid 17.8 SL 100ml/ha
  at 15 and 30 days after transplanting. The vegetation on the bunds should also be sprayed with the insecticides.
• Special detection technique
  PCR detection facilities available at the Department of Plant Pathology, TNAU, Coimbatore-3 can be used
  

• Plants affected by tungro exhibit stunting and reduced tillering. Their leaves become yellow or orange-yellow, may also have rust-colored spots.
• Discoloration begins from leaf tip and extends down to the blade or the lower leaf portion
• Delayed flowering, - panicles small and not completely exerted
• Most panicles sterile or partially filled grains
  

• Apply Neem cake at 150 kg/ha
  Botanical
• Foliar spray with Neem oil at 3% (15 lit /ha) starting from disease appearance
  

• Carbendazim 50 WP @ 500g/ha
• Azoxystrobin @ 500ml/ha
• Hexaconazole 75% WG @ 100mg/ lit 1st spray at the time of disease appearance and 2nd spray 15 days later

• Seed Treatment with TNAU Pf 1liquid formulation @ 10 ml/kg of seeds
• Seedling root dipping with TNAU Pf 1liquid formulation (500 ml for one hectare seedlings)
• Soil application with TNAU Pf 1liquid formulation (500ml/ha)
• Foliar spray with TNAU Pf 1liquid formulation @ 5ml/lit

• Irregular spots or lesions, with dark reddish brown margins and gray center
• Discoloration in the flag leaf sheath
• Lesions enlarge and often coalesce and may cover the entire leaf sheath
• Severe infection causes entire or parts of  young panicles to remain within the sheath
• Unemerged panicles rot and florets turn red-brown to dark brown
• Whitish powdery growth inside the affected sheaths and young panicles
• Infected panicles sterile, shrivelled, or with partially filled grain.

• Apply Gypsum @ 500 kg/ha at two equal splits once basally and another at active tillering stage.
• Botanicals
• Neem oil 3%
• Ipomoea leaf powder extract (25 kg/ha)
• Prosopis leaf powder extract (25 kg/ha). First spray at boot leaf stage and second 15 days later
  
  
  

• Spray any one of the following:
• Carbendazim @ 500g/ha
• Metominostrobin @ 500 ml/ha
• Hexaconazole 75% WG @ 100 mg/ lit 1st spray at the time of disease appearance and 2nd spray 15 days later

• Seed Treatment with TNAU Pf 1liquid formulation @ 10 ml/kg of seeds
• Seedling root dipping with TNAU Pf 1liquid formulation (500 ml for one hectare seedlings)
• Soil application with TNAU Pf 1liquid formulation (500ml/ha)
• Foliar spray with TNAU Pf 1liquid formulation @ 5ml/lit

Also called as sesame leaf spot or Helminthosporiose or fungal blight

Mostly seen in West Bengal, Orissa, A.P and Tamil Nadu

• Occur in nursery as well as main field
• Causes blight of seedlings
• Leaf spotting is very common
• Isolated brown, round to oval (resemble sesame seed)
• Spots measures 0.5 to 2.0mm in breadth - coalesce to form large patches.
• Seed also infected (black or brown spots on glumes spots are covered by olivaceous velvety growth)
• Infection also occurs on panicle neck with brown colour appearance
• 50% yield reduction in severe cases

Healthy field

Infected leaf

Advanced stage of infection

• Also called as sesame leaf spot or Helminthosporiose or fungal blight
• Mostly seen in West Bengal, Orissa, A.P and Tamil Nadu

• Occur in nursery as well as main field
• Causes blight of seedlings
• Leaf spotting is very common
• Isolated brown, round to oval (resemble sesame seed)
• Spots measures 0.5 to 2.0mm in breadth - coalesce to form large patches.
• Seed also infected (black or brown spots on glumes spots are covered by olivaceous velvety growth)
• Infection also occurs on panicle neck with brown colour appearance
• 50% yield reduction in severe cases

• Metominostrobin @ 500ml/ha
  

• Only few grains in a panicle are usually infected and the rest are normal
• Individual rice grain transformed into a mass of yellow fruiting bodies
• Growth of velvety spores that enclose floral parts
• Immature spores slightly flattened, smooth, yellow, and covered by a membrane
• Growth of spores result to broken membrane
• Mature spores orange and turn yellowish green or greenish black

Healthy grain

Infected panicle

Infected grain

• Two sprayings of Propiconazole 25 EC @ 500ml/ha (or) Copper hydroxide 77 WP @ 1.25 kg/ha at boot leaf and 50% flowering stages

• Drechslera oryzae, Curvularia lunata, Sarocladium oryzae, Phoma sp., Microdochium sp., Nigrosporasp. and Fusarium sp.,
• Grains are infected either after milk stage or after harvest or during storage
• Infection may be internal or external causing discoluration of the glumes or kernels
• Dark brown or black spots appear on grains
• Under humid condition prominent fungal growth

Discolouration of grains	Black Spots Appear on Grains with Prominent Fungal Discolouration	Black Spots Appear on Grains	Fungal Growth on Grains

• Spray - Carbendazim + Thiram + Mancozeb (1:1:1) 0.2% at 50% flowering stage.
  

• Initially, small, dark-green, water-soaked translucent streaks on veins from tillering to booting stage
• Lesions turn brown and bacteria ooze out under humid weather.

• Spray fresh cowdung water extract 20%
• Copper hydroxide 77 WP@1.25 kg/ha is also recommended