Recommendations for Rice Crop
- Plants affected by tungro exhibit stunting and reduced tillering. Their leaves become yellow or orange-yellow, may also have rust-colored spots. The leaf discoloration starts from the tip and may or may not extend to the lower part of the leaf blade; often only the upper portion is discolored.. Infected plants have delayed flowering. Tungro are transmitted by the green leafhoppers.
1. Application of Carbofuran 3G @ 10-12 kg/acre or spraying of Imidaclorprid 200SL @ 40ml or Chloropyriphos 20 EC @ 500ml in 200 litres of water. Repeat after 7 -10 days if needed.
2. Leaf yellowing can be minimized by spraying 2 % urea mixed with Mancozeb at 2.5 gm/lit.
3. Instead of urea foliar fertilizer like multi-K (potassium nitrate) can be sprayed at 1 per cent which impart resistance also because of high potassium content.
- Initial symptoms white to gray-green lesions or spots with darker borders produced on all parts of shoot Older lesions elliptical or spindle-shaped and whitish to gray with necrotic borders Lesions wide in the center and pointed toward either end Lesions may enlarge and coalesce to kill the entire leaves Symptoms also observed on leaf collar, culm, culm nodes, and the panicle neck node Nodal infection causes the culm to break at the infected node Few, no seeds, or whiteheads when neck is infected or rotten.
1. Manipulation of planting time and fertilizer and water management is advised. Early sowing of seeds after the onset of the rainy season is more advisable than late-sown crops. Excessive use of fertilizer should be avoided. Nitrogen should be applied in small increments at any time.
2. Spray tricylazole 75% WP @ 0.6gm/ litre or Propiconazole 25% EC 1ml/ litre or Carbendazim 50% WP @ 1gm/litre of water.
- Infected seedlings have small, circular or oval, brown lesions, which may girdle the coleoptile and cause distortion of the primary and secondary leaves Infected seedlings become stunted or die Young or underdeveloped lesions on older leaves are small and circular, dark brown or purplish brown A fully developed lesion on older leaves is oval, brown with gray or whitish center with reddish brown margin When infection is severe, the lesions may coalesce, killing large areas of affected leaves. Infected glumes with black or dark brown spots Velvety appearance of lesions on infected glumes under severe conditions
1. Spraying of crop at tillering and late booting stages with Carbendazim 12% + Mancozeb 63% WP @ 1gm/litre or Zineb @ 2 gm/litre of water. Repeat spray after 15 days.
- Individual rice grain transformed into a mass of velvety spores or yellow fruiting bodies Growth of velvety spores 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 Only few grains in a panicle are usually infected and the rest are normal
1. At Boot stage spraying of Copper oxychloride 50% WP @ 2.5 gm/liter. If disease persists spray crop with Propiconazole 25% EC @ 1ml/litre of water after 15 days interval for effective control of disease.
- Initial lesions are small, ellipsoidal or ovoid, greenish-gray and water-soaked and usually develop near the water line in lowland fields Older lesions are elliptical or ovoid with a grayish white center and light brown to dark brown margin Lesions may reach the uppermost leaf under favorable conditions Lesions may coalesce forming bigger lesions with irregular outline and may cause the death of the whole leaf Severely infected plants produced poorly filled or empty grains, especially those on the lower portion of the panicles
1. Spray the crop with Propiconazole 25% EC @ 1ml/litre or Carbenbendazim 50% WP @ 1gm/litre or Hexaconazole 5% EC @ 1 ml/lit of water at booting stage. Repeat the spray after 15 days interval.
- Oblong or irregular spots with chocolate brown coloration may develop on boot leaf sheathYoung panicles may not emerge and rot completely or emerge only partiallyGrains inside the chocked panicles and on the partially emerged panicles may be chaffy, light to dark brown and covered by a white to light-pink mat of mycelium and spore mass.Grains may be partially or completely filled and glume discoloration is noticed
1. Same as for sheath blight.
- Initial symptoms are small, irregular black lesions on the outer leaf sheath near water level Lesions expand as the disease advances Infected stem rots Visible numerous tiny white and black sclerotia and mycelium inside the infected culms Infected culm lodges and caused unfilled panicles and chalky grain Severe infection causes tiller death The disease aggravates the plants to lodge.
1. Spraying of crop at disease initiation with thiophanate-methyl 70% WP @ 1gm/lit or Valigamycin 3L @ 2.5 ml/litre of water.
Nature of Damage
- Translucent white patches that are parallel to the leaf veins .
- White, grub like larvae are seen mining through leaf tissues.
- Spiny black metallic beetles feeds on the upper surface of leaves producing bold white streaks.
1. Spray quinalphos 25 EC @ 2000 ml/ ha or monocrotophos 36 WSC @ 850 ml / ha or chlorpyriphos 20 EC @ 1500 ml/ ha or Triazophos 40 EC @ 2ml/liter of water.
2. ETL- 2 larva or Adults /hill.
- Presence of feeding damage on leaves which are tranparent white. Leaf tips are cut
- Presence of leaf cases attached onto leaf sheaths or floating on the water with larvae.
- Green larvae or pupae are found along with white feeding symtoms on leaves
1. Same as rice hispa.
- Leaves fold longitudinally and larvae remains inside.
- Larvae scrapes the green tissues of the leaves and becomes white and dry.
- During severe infestation the whole field exhibits scorched appearance
1. Spray cartap hydrochloride 50 WP@ 600 g a.i./ ha or monocrotophos 36 WSC @ 850 ml /ha or chlorpyriphos 20 EC @ 1500 ml/ ha or
Triazophos 40 EC @ 2ml/liter of water.
2. ETL-2 - 3 freshly folded leaves/hill.
- These are sucking insects, confining themselves to basal portion of the rice-plant and deplete plant sap from phloem tissue. As a result, plant gets wilted and dries. Drying of plant starts in circular patches in field and later whole field dries off. This typical symptom is called "hopper-burn. Besides, BPH acts as the vector of virus diseases grassy stunt, ragged stunt and wilted stunt.
- GPH act as the vector of Tungro viral diseases.
1. Application of Carbofuran 3G @ 10-12 kg/acre or spraying of Imidaclorprid 200SL @ 40ml or Chloropyriphos 20 EC @ 500ml in 200 litres of water. Repeat after 7 -10 days if needed. For effective control spray towards the base of the plant.
2. ETL- 5-7 plant hoppers /hill.
- Caterpillars bore central shoot of seedlings and tillers leading to death of central shoot called "Dead Heart".
- Panicle turn whitish, erect with chaffy spikelets and can be easily pulled out, is known as "white ears"
1. Application of Carbofuran 3G @ 10-12 kg/acre or spraying of Chloropyriphos 20 EC @ 500ml or monocrotophos 36 WSC @ 850 ml / ha or cartap hydrochloride 50 WP@ 600 g a.i./ ha or Triazophos 40 EC @ 2ml/litre of water
2. ETL- 5% Dead hearts
Swarming caterpillar/army worm
- Caterpillars eat the leaves of the rice plant leaving irregular notches
- In severe infestation whole leaf and plants are eaten leaving stubs in the field
- Presence of caterpillars , fecal matter and feeding damage
1. Spray chlorpyriphos 20 EC @ 2500 ml ha/1 or monocrotophos 36 WSC @ 1500 ml ha/1 or acephate 50 WP @ 1200 g/ ha or endosulfan 35 EC @ 1500 ml/ ha or carbaryl 50% WP @ 4gm/ litre of water.
Submitted by arun khajuria on Tue, 30/08/2011 - 23:25