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Agricultural crops :: Pulses :: Redgram

Redgram Diseases

Alternaria Leaf Spot - Alternaria alternata

Collar Rot - Sclerotium rolfsii

Dry root Rot - Macrophomina phaseolina (Rhizoctonia bataticola)

Fusarium Wilt - Fusarium udum


Powdery Mildew - Oidiopsis taurica

Pigeon pea sterility Mosaic(PPSMV)

Mungbean yellow mosaic virus(MVMV)

Alternaria Leaf Spot-Alternaria  alternata

Symptom
  • Initially small necrotic spots appear on the leaves, and these gradually increase in size to characteristic lesions with dark and light brown concentric rings with a wary outline and purple margin.
  • As infection progresses, the lesions enlarge and coalesce.
  • The disease is mostly confined to older leaves in adult plants, but may infect new leaves of young plants, particularly in the post rainy-season crop.  
Healthy leaf
Initial stage Advanced stage

Management
  • Spray Mancozeb 1kg/ha



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Collar Rot : Sclerotium rolfsii

Symptom
  • The disease incidence is usually observed at the seedling stage.
  • It causes substantial seedling mortality within 45 DAs in situations where pigeonpea is sown in warm weather soon after a preceding cereal crop; and particularly when the crop stubble remains close to the soil surface.
  • The pathogen finds an excellent substrate in undecomposed stubble, and emerging pigeonpea seedlings show mortality due to attack by the pathogen.

Management
  • Disease incidence can be reduced if the previous crop stubble is buried deep, and is allowed to decompose well before pigeonpea is sown.
  • Seed dressing with fungicides such as Trichoderma viride 4g/kg of seed or Carbendazim 2g/kg of seed orPseudomonas fluorescens 4g/kg of seed should also reduce seedling mortality.
  • Soil application of T.viride @ 2.5 kg/ha mixed with 50 kg FYM.
  • Spot drenching with Carbendazim 1g /kg (T.viride & fungicide should not be mixed.



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Dry Root Rot : Macrophomina phaseolina (Rhizoctonia bataticola)

Symptom
  • Typical symptoms include root and basal stem rot with a large number of minute, fungal sclerotia visible under the bark.
  • Plants dry prematurely, particularly when they face drought stress. Infection of seedlings and leaf infection has been reported from India.
  • Disease incidence severe in off-season, irrigated, summer crops in several parts of India, and it is a minor one in the normal-season crop. The pathogen is both soil- and seed borne.
Healthy leaf 
Black spot (Sclerotia) on the stem

Management
  • Spot drenching with Carbendazim @ 1 gm/ lit



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Fusarium Wilt: Fusarium udum

Symptom
  • Symptoms can appear 4 to 6 weeks after sowing. The initial visible symptoms are loss of turgidity in leaves, and slight interveinal clearing.
  • The foliage shows slight chlorosis and sometimes becomes bright yellow before wilting.
  • Leaves are retained on wilted plants. The initial characteristic internal symptom of wilt is the browning of the xylem vessels from the root system to the stems.
  • The xylem gradually develops black streaks, and brown or dark purple bands appear on the stem surface of partially wilted plants extending upwards from the base.
  • When the bark of such bands is peeled off, browning or blackening of the wood beneath can be seen. in wilt-tolerant genotypes these bands are confined to the basal part of the plant.
  • Sometimes, especially in the later stages of crop growth, the branches dry from the top downwards, but symptoms are not seen on the lower portions of the main stem or branches.
  • Small branches on the lower part of the plant also dry.
  • When the main stem of such plants is split open, intensive blackening of the xylem can be seen.
  • In humid weather, a pinkish mycelial growth is commonly observed the basal portions of the wilted plants.
  • Partial wilting is usually associated with lateral root infection. Tap root infection results in complete wilting.

Management
  • P. fluorescens (or) T. viride – 2.5 kg / ha + 50 kg of well decomposed FYM or sand at 30 days after sowing



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Powdery mildew: Oidiopsis taurica

Symptom
Healthy leaf
Infected leaf
Infected individual leaf
  • The disease has been reported from several countries including; Ethiopia, India, Kenya, Malawi, Tanzania, Uganda, and Zambia.
  • Although powdery mildew symptoms appear more often on old leaves, young leaves can also be infected under favourable weather conditions.
  • In cases of severe infection, affected leaves turn yellow and show twisting and crinkling.      
  • The host range of the pathogen is very wide and the inoculum is always present in pigeonpea-growing, semi-arid regions.

Management
  • Spray Carbendazim 1g/lit or Wettable sulphur 2.5g/lit.



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Sterility Mosaic Disease (SMD): Pigeonpea sterility mosaic virus (PPSMV)

Symptom
  • VectorAceria cajani
  • Sterility mosaic (SM) is the most important of pigeonpea in Tamil Nadu, Maharashtra, Gujarat, Punjab, U.P Leaves show mosaic motling.
  • Leaves become small and cluster near branch tips.
  • Diseased plants are pale green and bushy in appearance, without of flowers and pods.
  • Diseased plants are usually in groups.
  • Sometimes a plant may not show symptoms in the first flush, but when ratooned the new growth shows clear symptoms tend to disappear as the plants mature.
Infected leaf
Healthy leaf

Management
  • Rogue out the infected plants in the early stages of growth. Spray Fenazaquin @ 1 ml/lit on 45 and 60 DAS as prophylactic spray



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Yellow Mosaic: Mungbean yellow mosaic virus

Symptom
  • This disease was probably reported first from Sri Lanka.
  • The disease first appears in the form of yellow, diffused spots scattered on the leaf lamina, not limited by veins and veinlets.
  • Such spots slowly expand and in later stages of disease development, affected leaflets show broad, yellow patches alternating with green colour.
  • Sometimes the entire lamina turns yellow.
  • Leaf size is conspicuously reduced in early infections.
  • In peninsular India, disease incidence is relatively higher in late-sown pigeonpea.
  • The vector is Bemisia tabaci

Management
  • Rogue out the infected plants upto 40 days.
  • remove weed hosts periodically
  • Spray systemic insecticides to control the vector
Healthy leaf
Infected leaf

Updated on April, 2014


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