EU Compliant Paddy (Step 8)

Disease Management

Major diseases

1. Brown spot

Identification Recommendation:

  • Small oval spots appear on the leaves, with a dark brown centre and a lighter brown edge.
  • The spots coalesce and enlarge, causing the leaves to dry out.
  • In severe cases, the leaves appear scorched and weak.
  • Spots may also appear on the ears and grains.

Symptoms:

  • It produces oval, eye-shaped spots with a conspicuous dark-brown dot in the centre and light brown margin. Spots are also produced on the grains. This disease occurs in poor soils, therefore, give adequate and balanced nutrition to the crop.

Management

  • To control the disease spray Isopyrazam 11.5% + Difenoconazole 11.5% SC @ 160 ml per acre at 35-40 days after transplanting. Then spray Azoxystrobin 18.2% + Difenoconazole 11.4% SC @ 200 ml per acre at 60-65 days after transplanting followed by at 80-85 days after transplanting.

2. Bacterial Leaf Blight

Identification Recommendation:

  • Leaves start yellowing from the tips or margins and gradually dry.
  • Water-soaked yellow lesions appear on leaves, which later develop into elongated streaks.
  • In the morning, bacterial ooze (milky sticky secretion) can be seen from cut or infected parts.
  • In severe cases, the entire leaf appears scorched and dried.
  • In nursery and early stages, “Kresek” symptoms occur—sudden wilting of the entire plant.
  • The disease spreads rapidly under high humidity, rainfall, and strong winds.
  • Immediate control measures should be taken as soon as symptoms appear.

Symptoms:

  • The leaves start drying completely from the tip or edge, due to which they become crooked.
  • Water-soaked to yellowish stripes on leaf blades or starting at leaf tips then later increase in length and width with a wavy margin.
  • Appearance of bacterial ooze that looks like a milky or opaque dewdrop on young lesions early in the morning.

Management:

  • Seed treatment should be done with streptocycline before sowing.
  • Spray Copper Hydroxide 53.8% DF @ 400g per acre
  • Foliar spray of Streptocyclin 90 % w/w + Copper oxychloride 50 % WP @ 6 gms + 250 gms per acre at 30-40 days after transplanting.

3. Khaira disease

Identification Recommendation:

  • Leaves begin to turn yellow 2–4 weeks after transplanting.
  • Small copper/brown spots appear on the leaves.
  • New leaves become lighter and appear white or yellow.
  • Plant growth is stunted and plants become weak.
  • Leaves dry out and begin to fall off.
  • This problem is more common in zinc-deficient fields.

Symptoms:

  • The leaves turn yellow develop coppery spots 2–4 weeks after transplanting; new leaves turn white, while fertilizers show little effect

Management:

  • Broadcast Librel 12 % Zn EDTA @ 500 gm per acre at 15- 25 days after tranaplanting.
  • ZnSO₄ – Apply 16 kg/acre in basal; there should not be any major problem.

4. Rice blast

Identification Recommendation

  • Spindle-shaped lesions develop on leaves with an ash-grey centre and brown margins.
  • Lesions enlarge and coalesce, making leaves appear scorched.
  • In early stages, small brown spots gradually enlarge and become more distinct.
  • The disease spreads rapidly under high humidity and cool weather conditions.
  • In severe cases, the entire leaf may dry up.

Symptoms:

  • The fungus causes spindle shaped spots with greyish centre and brown margin on the leaves at maximum tillering. It also causes brown lesions on the neck of the panicle, showing neck rot symptoms and the panicles fall over. The disease is more severe on Basmati cultivars particularly in the sub-mountainous areas and under application of heavy nitrogenous fertilizers.

Management:

  • Foliar spray of Isoprothiolane 40 EC @ 350 ml per acre at 80-85 days after transplanting.

Biological control:

  • Dry seed treatment with Pseudomonas fluorescens talc formulation @10g/kg of seed.
  • Spray P. fluorescens talc formulation @ 0.5% from 45 days after transplanting at 10 day intervals, three times.

5. Sheath Blight

Identification Recommendation

  • Greenish-brown or brown oval spots appear on the leaf sheath
  • Spots enlarge and merge with each other and spread to upper leaves
  • Under high humidity, white fungal growth or web-like mycelium appears on the lesions
  • Infected plants become weak and may lodge (bend or fall over)
  • The disease spreads rapidly in the field in patches or grouped areas

Symptoms:

  • Greyish green lesions with purple margin develop on the leaf-sheath above the water level. Later, the lesions enlarge and coalesce with other lesions. The severe attack results in the poor filling of the grains. Destroy the rice straw and stubbles after harvesting the affected crop. Avoid the excessive use of nitrogenous fertilizers. Keep the bunds clean by removing the grass.

Management:

  • spray Isopyrazam 11.5% + Difenoconazole 11.5% SC @ 160 ml per acre at 35-40 days after transplanting. Then spray Azoxystrobin 18.2% + Difenoconazole 11.4% SC @ 200 ml per acre at 60-65 days after transplanting followed by at 80-85 days after transplanting.

Biological methods:

  • Seed treatment with Pseudomonas fluorescens @ of 10g/kg of seed .
  • Soil application of P.fluorescens @ of 2.5 kg/ha after 30 days of transplanting (This product should be mixed with 50 kg of FYM/Sand and then applied)
  • Foliar spray of Pseudomonas fluorescens at 0.2% concentration ,commencing from 45 days after transplanting at 10 days interval for 3 times depending upon the intensity of disease.

6. False smutt

Identification Recommendation

  • In panicles, some grains transform into orange/yellow velvety balls (smut balls)
  • These balls later burst and release orange spores
  • Infected grains appear larger and softer than normal grains
  • The disease appears sporadically on individual plants or panicles in the field
  • The incidence increases rapidly under high humidity and cloudy weather conditions

Symptoms:

  • It is a fungal disease in which the individual grains transform into large yellowish/greenish velvety spore-balls High relative humidity, rainy and cloudy days during the flowering period increase the incidence of the disease. The application of organic manures and high dose of nitrogenous fertilizers also increases the intensity of attack.

Management:

  • Spray Azoxystrobin 18.2% + Difenoconazole 11.4% SC @ 200 ml per acre at 60-65 days after transplanting followed by at 80-85 days after transplanting.
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