Sunday, October 23, 2011

Pegeon pea diseases


List of pigeonpea diseases

1 Bacterial diseases                                                                                                                                   
2 Fungal diseases                                                                                                                                       
3 Nematodes, parasitic                                                                                                                              
4 Viral diseases                                                                                                                                          
5 Miscellaneous diseases and disorder                                                                                                    


Bacterial diseasesBacterial diseases
------------------------------------------------------------------------------------------------------------------------------------ 

1.Bacterial leaf spot and stem canker       Xanthomonas campestris pv. cajani
                                                                   
                                                                  Bacterial leaf spot and stem canker


                                                                 Causal Organism
                                                                 Xanthomonas campestris pv. cajani
                                                                 Damage 
                                                                 Necrotic spots on leaves with yellow hallow.
                                                                 Defoliation of lower leaves in severe case of infection.
                                                                 Cankerous lesions on stem resulting in their breakage.
                                                                 In severe infestation, the affected branches dry.

                                                                 Survival & Favourable Conditions
                                                                 Warm and humid weather favour disease development.
                                                                 The pathogen is specific to pigeon pea and is seed borne

                                                                  Cultural Control
                                                                  Use resistant varieties.
                                                                  Select well drained fields.
                                                                  Always selects seeds from healthy crops.

                                                                   Chemical Control
                                        Spray antibiotics like streptocycline and 250 ppm i.e. 2.5 g/10 lit of water.  


2.Halo blight                                                  Pseudomonas amygdali pv. phaseolicola
                                                                    ----------------------------------------------------------------
                                                                    Halo blight                                                                              
                                                                    Causal Organism
                                                                    Pseudomonas syringae pv. phaseolicola

                                                                    Damage 
                                                                    Dark brown angular necrotic spots 1 mm in diameter                                                                                     surrounded by large chlorotic halos 10 mm in diameter are seen                                                                     on the soft, young leaves of older and ratooned plants.

                                                                    Survival & Favourable Conditions
                                                                    Persistent rains and cloudy weather result in severe disease                                                                             development.

                                                                    Cultural Control
                                                                    Always use resistant varieties

                                                                    Chemical Control
                                                                   Spray antibiotics like streptomycine and tetracycline @ 100                                                                                                                                micro gms/litre of water.
                                                                   -----------------------------------------------------------------


2.Fungal Diseases

Disease Name                   Casual Organisms
--------------------------------------------------------------------------------------------------------------------------------- 

Alternaria blight                      Alternaria alternata
                                              Alternaria tenuissima
                                              Alternaria sp
                                              ------------------------------------------------------------------------------
                                              Alternaria blight                                                                                             


                                              Causal Organism
 
                                              Alternaria sp,
                                              Alternaria tenuissima,
                                              Alternaria alternata

                                              Damage
                                              These cause blighting of leaves                                                   and severe defoliation and drying                                               of infected branches.
                                             
                                              Brown spots on the leaves with                                                   concentric rings.

                                              The lesions appear on all aerial                                                   plant parts including pods.

                                              Defoliation of leaves and death of                                               tender branches.

                                              Survival & Favourable Conditions

                                              The fungus sporulates well under warm, humid conditions.
                                              Late sown crop or post rainy season favours disease development.

                                              Cultural Control
                                              Use resistant varieties.
                                              Avoid fields close to perennial pigeon pea.
                                              Select seed from healthy plant
                                              Sow early

                                              Chemical Control
                                              Spray macozeb @ 3g/litre of water.                                                             
                                              -------------------------------------------------------------------------------
Anthracnose                           Colletotrichum cajani
                                              Colletotrichum truncatum

Armillaria root rot                   Armillaria mellea

Botryodiplodia blight               Lasiodiplodia theobromae
                                               = Botryodiplodia theobromae

Botryosphaeria stem canker     Botryosphaeria xanthocephala
                                               Fusicoccum cajani [anamorph]

Botrytis gray mold                   Botrytis cinerea
                                               Botrytis gray mold
                                               ---------------------------------------------------------------------------  
                                               Botrytis gray mold                                                                                                                                          Causal Organism
                                               Botrytis cinerea
infected flowers
                                             
                                               Damage
                                               Dark gray fungal growth on the growing tips, flowers and pods.
                                               Infected flowers drop, thus reducing pod set.

                                               Survival & Favourable Conditions
                                               The shed flowers and leaves on the ground are covered with sporulating                                                                                                                                   mycelium of the fungus.
                                               It survives on infected debris and is better at 10o C.
                                               It survives and remain ineffective up to 8 months in soil.
 
                                               Cultural Control
                                               Deep summer ploughing.
                                               Reduce plant density and increase in air passage between the plants.
 
                                               Biological Control
                                               Use Trichoderma spp. as bio-control agents.

                                               Chemical Control
                                               Spray mancozeb @ 3g/litre of water.                                                         
                                               ------------------------------------------------------------------------------
Cercoseptoria leaf spot           Cercoseptoria cajanicola

Cercospora leaf spot               Mycovellosiella cajani

                                               = Cercospora cajani
                                               Cercospora indica
                                               Cercospora instabilis
                                               Cercospora thirumalacharii
                                               -----------------------------------------------------------------------------
                                               Cercospora leaf spot                                                                                   

                                               Causal Organism
                                               Cercospora cajani, Cercospora indica

                                               Damage 
                                             
                                               Necrotic spots on all aerial parts mainly on leaves and leaf spot stems.
                                               The circular spots on leaves coalesce when the weather is cool and humid                                                                                                                           leading to severe defoliation.
                                               Severe infection leads to the die back of the tender branches o the plant.
                                       
                                               Survival & Favourable Conditions
                                               Cool temp and humid weather favour the disease
                                 
                                               Cultural Control
                                     
                                               Use resistant varieties.
                                               Select field away from perennial pigeon peas which are a source of inoculum.
                                               Always select seeds from healthy plants.
                                   
                                               Chemical Control
                                               Spray maneb @ 3g/litre of water or carbendazim 1 g/litre.                              
                                               ------------------------------------------------------------------------------
Cladosporium leaf blight           Cladosporium oxysporum

Cladosporium leaf spot             Cladosporium cladosporioides

Collar rot                                 Sclerotium rolfsii

                                               Athelia rolfsii [teleomorph]
                                               = Corticium rolfsii
                                               Collar rot                                                                                                      
                                              
                                               Causal Organism
                                               Sclerotium rolfsii Saccardo

                                               Damage 


                                                Usually appears within a month of sowing scattered over the field.
                                                Seedlings turn slightly chlorotic before they die.
                                                Rotting in the collar region covered with white mycelial growth; this                                                                 differentiates collar rot from other seedling diseases caused by Fusarium,                                                         Rhizoctonia, or Pythium.
                                                Affected seedlings can be easily uprooted, but the lower part of the root                                                         usually remains in soil.

                                                Survival & Favourable Conditions
                                                Temperatures of about 30o C and soil moisture at sowing predispose                                                             seedlings to infection.
                                                This is severe in early-sown (june) than in later- sown crops.
                                                The pathogen finds an excellent substrate in un decomposed stubble.

                                                Cultural Control
                                                Deep summer ploughing
                                                Select well drained fields
                                                Keep the fields free from un decomposed organic matter.
                                                Sow when soil moisture is low.
                                                Select fields where cereal crops have not been grown during the
                                                previous season.

                                                Mechanical Control
                                                Collect cereal stubbles from the field and destroy them before sowing pigeon                                                  pea

                                                Chemical Control
                                                Seed treatment with Thiram or captan @ 3 g/kg                                    
                                                OR                                                                                                               
                                                Thiram + Carbendazim (2:1) 0.25 %                                                         

                                                -----------------------------------------------------------------------------

Colletotrichum stem canker      Colletotrichum crassipes

Damping-off                             Pythium aphanidermatum
                                                Pythium splendens var. hawaiianum

Dieback and stem canker          Colletotrichum capsici

Diplodia stem canker                Diplodia cajani

Dry root rot                              Macrophomina phaseolina
                                                = Rhizoctonia bataticola

Fusarium leaf blight                   Fusarium pallidoroseum
                                                = Fusarium semitectum

Fusarium seedling rot                Fusarium avenaceum
                                                Fusarium equiseti

Fusarium wilt                            Fusarium udum
                                                Gibberella indica [teleomorph]
                                                Fusarium Wilt                                                                                               
                                                Causal Organism
                                                Fusarium udum
                                                Damage 


                                              Yellowing of the leaves followed by partial or complete premature death of the                                                plant.
                                               Dark brown to purple band on the main and lateral branches extending                                                          upwards from ground black streaks under the bark.
                                               Dark brown to black discoloration of the xylem in the stem and root regions.

                                               Survival & Favourable Conditions
                                               The fungus survive on infected plant debris in the soil for about 3 years.
                                               Early sowing, good weed management and good crop growth encourage wilt                                                  development.
                                               Low soil temperature and increasing plant maturity favoured wilt

                                               Cultural Control
                                               Use resistant varieties.
                                               Select a field with no previous record of wilt for at least past 3 years.
                                               Do summer ploughing.
                                               Select seed from disease free fields.
                                               Grow pigeon pea intercropped or mixed with cereal crops like sorghum.
                                               Rotate pigeon pea with sorghum, tobacco or castor every three years.
                                               Uproot the wilted plant and use them as firewood or destroy them.
                                               Solarize the field in summer to help reduce the inoculum.v
Biological Control
Soil application of 5kg of Trichoderma formulation/ha mixed with FYM can also be used to combat the disease.
Seed treatment with 4g Trichoderma viridae formulation + 2 g of vitavax/kg of seed
Mechanical Control
Soil application of 5kg of Trichoderma formulation/ha mixed with FYM can also be used to combat the disease.
Seed treatment with 4g Trichoderma viridae formulation + 2 g of vitavax/kg of seed
Chemical Control
Seed dressing with carbendazim 50% + thiram 50% @ 3 g/kg of seed.
OR
Seed treatment with carboxin + thiram (1:2) at the rate of 3g/kg of seed.

Macrophomina stem canker      Macrophomina phaseolina
                                                =Rhizoctonia bataticola

Myrothecium leaf spot              Myrothecium gramineum
                                                Myrothecium roridum

Neocosmospora root rot          Neocosmospora vasinfecta

Periconia leaf spot                    Periconia byssoides

Phaeoisariopsis leaf spot           Phaeoisariopsis griseola

Phoma stem canker                  Phoma cajani

Phyllosticta leaf spot                 Phyllosticta cajani

Phytophthora blight                  Phytophthora drechsleri f.sp. cajani

Phytophthora root rot and
                       stem blight        Phytophthora drechsleri

Phytophthora Stem Canker      Phytophthora nicotianae var. parasitica
                                                = Phytophthora parasitica

Powdery mildew                      Leveillula taurica
                                               Oidiopsis taurica [anamorph]
                                               Ovulariopsis ellipsospora

Rust                                         Uredo cajani
                                                -----------------------------------------------------------------------------
                                                Rust                                                                                                           
                                                  
                                               Causal Organism
                                               Uredo cajani

                                               Damage 
                                               Dark brown raised pustules full of uredia on the lower leaf surfaces.
                                               The infected leaves desiccate, and drop off.
                                               Extensive defoliation when infections are severe.

                                               Survival & Favourable Conditions
                                               Dense planting, light rain, wind and cloudiness encourage disease                                                                    development.

                                               Disease severity increases with the onset of flowering.

                                               Cultural Control
                                               Use resistant varieties
                                               Avoid sowing pigeon pea close to bean fields.
                                               Rotate crops to reduce the chance of pathogen survival.

                                               Chemical Control
                                               Spray maneb @ 3g/litre of water.                                                               
                                               -----------------------------------------------------------------------------
Sclerotinia stem rot                   Sclerotinia sclerotiorum

Seedling or seed rot                  Aspergillus flavus
                                                Aspergillus niger

Synchytrium brown gall
                        and wilt            Synchytrium phaseoli-radiati

Synchytrium orange gall            Synchytrium umbilicatum

Web blight                               Thanatephorus cucumeris
                                                Rhizoctonia solani [anamorph]

Wet leaf rot                              Choanephora cucurbitarum

Wet root rot                             Rhizoctonia solani
                                                Thanatephorus cucumeris [teleomorph]



Nematodes, parasitic

---------------------------------------------------------------------------------------------------------------------------------- 

Dirty root (reniform nematode)     Rotylenchulus reniformis

Lance nematode                          Aphasmatylenchus
                                                   Hoplolaimus seinhorsti

Pearly root (cyst nematode)         Heterodera cajani

Root-knot (root-knot nematode) Meloidogyne acronea
                                                   Meloidogyne arenaria
                                                   Meloidogyne incognita
                                                   Meloidogyne javanica

Viral diseases
----------------------------------------------------------------------------------------------------------------------------------- 
Arhar mosaic                              Arhar mosaic virus

Foliar vein yellowing                    Rhabdovirus

Mild mosaic                                Tobacco mosaic virus

Mosaic                                       Alfalfa mosaic virus
                                                  Cowpea mosaic virus

Phyllody                                     Mycoplasma-like organism

Rhynchosia little leaf                    Mycoplasma-like organism

Rhynchosia Mosaic                     Rosette
                                                  Mycoplasma-like organism
                                                  Virus (most likely)

Sterility mosaic                           Unknown
                                                  Sterility mosaic                                                                                            
                                                  Causal Organism
                                                  Eriophyid mite Aceria cajani


                                                  Damage 


                                                  Bushy and stunted appearance of the infected plants due to reduction in the                                                     size of the leaves and proliferation of the branches.

                                                  Light and dark green mosaic pattern on the infected leaves of younger                                                             plants.

                                                  Partial or complete sterility of the plant resulting in low or no flowering and                                                     podding.
 

                                                  Survival & Favourable Conditions
                                                  Shade and humidity encourage multiplication of the virus.

                                                  Cultural Control
                                         
                                                  Use resistant varieties.
                                                  The crop must be sown timely.
                                                  The spacing between the lines should be maintained at 30 to 40 cms.
                                                  Only certified seeds should be used for sowing.
                                                   If the seeds are not treated then seed treatment should be done.
                                                   In endemic areas only tolerant and resistant varieties should be used.
                                                   Weeds plants should be rouged out at their inception.
                                                   Insect, fungal and nematode vectors should be controlled using suitable                                                          pesticides.
                                                   Control white fly as it spreads the virus.

                                                   Mechanical Control
                                                   Destroy sources of sterility mosaic inoculum
                                                   Uproot infected plants at an early stage of disease development and destroy                                                    them

                                                   Chemical Control
                                                   Seed dressing with 25% furadan 3G.                                                      
                                                   OR                                                                                                        
                                                   10 % aldicarb @ 3g/kg of seed.                                                              
                                                   OR                                                                                                        
                                                   Spraying acaricide or insecticide like metasystox or kelthane @ 0.1% to                                                        control the mite vector in the early stages of plant growth.                          


Witches' broom                          Mycoplasma-like organism

Yellow mosaic                            Mung bean yellow mosaic virus
                                                 ----------------------------------------------------------------------------
                                                  Yellow mosaic                                                                                         
                                                 
                                                   

                                                  Causal Organism
                                                  Mung bean yellow mosaic virus

                                                  Damage 
                                                  Green and mosaic mottle symptoms are seen on the leaves.
                                                  Diseased plants are scattered in the field and produce fewer pods.

                                                  Cultural Control
                                                  Avoid sowing late to reduce disease severity.
                                                  Uproot and burn infected plants if the disease appears on isolated plants in                                                     the field.

                                                  Chemical Control
                                                  Spray insecticide (metasystox @ 1 g/L to control the white fly             
                                                  ---------------------------------------------------------------------------- 
Miscellaneous diseases and disorders
----------------------------------------------------------------------------------------------------------------------------------- 
Marginal leaf burn

Salinity injury (most likely)

Insect Management

Red gram crop is attacked by a number of insect pests like pod borers, tur pod fly, plume moth, hairy caterpillar, leaf hopper, bean fly etc. but the pod borers are found to cause a considerable loss to the crop.


1. Gram caterpillar Helicoverpa armigera
Major pest on red gram in all areas and highly polyphagous in nature. Fully grown caterpillar is greenish with dark brown lines on the sides of the body.
The adult moth is medium in size, stout and grey to pale brown in colour. Dark spots are seen in the forewings.

Presence of bore holes on the pods, flowers and defoliation in the early stages are the main symptoms.
The young larva is green in colour. It feeds on tender leaves by scraping green tissue and the older larvae feed on buds, flowers and pods in a characteristic manner with its head and part of the body inside and remaining part outside the pods.

The larva after feeding on the developing or partly matured seeds moves to another one, leaving behind large round holes on each of the damaged locule.

Control:

Deep summer ploughing and removal of weeds
Sow resistant varieties
Synchronized sowing of red gram by the end of June preferably with short duration varieties in each cotton ecosystem.

Avoid Monocropping. Intercropping of early maturing pigeon pea with mung bean in alternate and paired row results in low infestation of pod borer.
Removal and destruction of crop residues to avoid carry over of the pest to the next season, and avoiding extended period of crop growth by continuous irrigation.

The population of pod borer can be regulated by using pheromone traps. In cases of heavy infestation, physical shaking of pigeon pea plants to dislodge larvae is favored.
Bird perches placed just above the crop canopy will also help to reduce the population of the pest.

Biological control:

Application of Nuclear Polyhedrosis Virus (NPV) @ 500 LE /ha with 10% cotton seed kernel extract, 10% crude sugar, 0.1% each of Tinopal and Teepol for effective control of Helicoverpa.
Applying HNPV at a rate of 500 larval equivalents (LE) per ha. At 15 days intervals.
Conservation and augmentation of natural predators and parasitoids for effective control of the pest.

Chemical control:

Any systemic insecticide should be used at 50 % flowering stage and after 10 - 15 days neem seed kernal extract should be used.

Spraying of 0.07 % Endosulfan (2ml of 35 EC / liter of water) or 0.04 % Monocrotophos (1 ml of 40 EC / liter of water) Fenvalerate or Cypermethrin will control the pest.

2. Plume moth Exelastis atomosa

A major pest noticed during November to March.
Adult is small moth with yellowish brown wings, forewings are cut into two plumes and hind wings into three.
The green oval eggs are laid singly on buds and pods.

Larvae are green or brown, spindle shaped and covered with spines and hair.
On the dorsum two thin yellow lines run along the body.

Pupae which are brownish, look like the larvae and are attached to the pod surface.
Caterpillars are more rampant during the post rainy season than during the rainy season.

The larvae bore into the flowers and pods and feed on developing grains. Control
Field sanitation by removing and destroying the damage plant parts and timely sowing of the crop.

Avoid Monocropping and adoption of mixed or intercropping with non host plants.
Crop rotation with non leguminous crop.

Spraying of NPV 625 LE/ha with adjuvants like Tinopol 0.1% + Jaggery 0.5%
Spraying of the suitable insecticides should be done at 50% flowering stage to protect the crop from the moth and larva.

Spray Endosulphan 35 EC at the rate of 2 l/ha. / Monocrotophos 36 SL at the rate of 1l/ha.


3. Green pod borer Etiella zinckenella

This pest is widely distributed and infestations of this pest build up by the end of the red gram season, when the temperatures are high.

Medium sized brown moths.
Elliptical eggs are laid in clusters on the developing pods.

The young larvae are green and later turn pinkish- red.
Larvae feed on the maturing seeds inside the pod, reaching a maximum length of 15 mm.

The larva feeds on maturing seeds after entering the pods.
Faucal pellets are seen inside the damaged pods.

Pupation takes place in the soil.

Control

Apply chemical insecticide only if the pest population crosses ETL.

Spraying of endosulfan 35 EC 0.07% (2ml of 35 EC/lit. of water) or monocrotophos 36SL 0.04% (1 ml of 36 SL /litre of water) or chlorpyriphos 20 EC @ 3.5 ml/lit. of water at 600-1000 lit. of spray material per ha. with hand sprayer.

4. Spotted pod borer Maruca testulalis

Major pest of red gram and other grain legume crops.
The forewings of the moth are brown in colour with white club shaped marking and hind wings are white with irregular blotch.

The eggs are oval and yellow laid in small batches commonly on terminals.
The larva is whitish-green with conspicuous black spots on its dorsal surface.

Pupation is in a silken cocoon in leaf webbings or on soil surface.
The larva webs together the leaves, buds and pods and feeds inside these webs.

The caterpillar also bores into pods and eats up the ripening seeds.
A crown mass of excrement is seen at the entrance into the larval burrow.

Control

Timely sowing should be done preferably up to first quarter of July.
Excess application of nitrogen should be avoided.

Water logging should be prevented.
Conserve ants and praying mantids as these are good predators of egg and larva of the pest.

If the pest population crosses ETL spray 0.07% endosulfan ( 2ml of 35 EC/lit. of water) or 0.04% monocrotophos ( 1 ml of 36 Sl /litre of water) or chlorpyriphos 20 EC @ 3.5 ml/lit. of water at 600-1000 lit. of spray material per ha. with hand sprayer.


5. Blue butterflies Lampides boeticus, Catochrysops strabo

Widely distributed and attack several cultivated and wild legumes.
Small blue butterflies with a black spot on the hind wing, and ashort hair like projection.

Single sculptured pale blue eggs are laid on buds.
Larvae are about 12 mm long, green, oval, flat, and slug-like

Pupation occurs in the soil or in plant debris.
The larvae feed on leaves, buds, flowers, and pods

Control

Natural enemies reduce the numbers.
Specific control is rarely required, but the general management recommendations for pod borers may be adopted.

6. Pod fly Melanagromyza obtusa

Commonly found major pest of red gram in India.
Adult is small black fly, insert eggs through the wall of the developing pod close to the grains.

Brown puparium is inside the pod but outside the seed.
Completes its life cycle in 3 weeks.

Maggot is milky white, legless and about 3 mm in size.
Five brownish strips runs along the entire mid dorsal line of the body.

The maggot feeds on the developing grain.
The infested pods do not show external evidence of damage until the fully grown larvae chew holes in the pod walls.

These bore the grains and make the tunnel in them.
This hole provides an emergence window through which the adults exit the pod.

Damaged grains do not mature and due to excreta fungus may develop in the grain.
The infested grains loose their viability.

Control

Sow resistant varieties.
Crop rotation with non leguminous crops.
Intercropping with jowar, maize or groundnut etc.
Conserve the parasite Ormyrus Sp.

Spary monocrotophos @ 36 SL @ 1 ml/lit or endosulfan 35 EC 2.0 ml/lit of water at 50 % flowering stage and after 10 - 15 days neem seed kernal extract should be used.

7. Pod wasp Taraostigmoides Sp.

Adult is a small yellowish brown wasp of 2 mm long.
Lays translucent flat, oval eggs are laid on the flowers and on the young pods.

Legless white larva of 2.5 mm long feeds on the young green seed of basal locules of pods causing complete abortion of seed resulting in single seeded pods.

Larva also feeds on the pod wall after consuming the seed.
When the pod is attacked immediately after fertilization, it dries and is shed.

Control

In India it is not causing any appreciable harm to warrant any control.
Insecticides used for the pod borers can control this pest.

In India it is not causing any appreciable harm to warrant any control.
Insecticides used for the pod borers can control this pest.

8. Blister beetle Mylabris pustulata

Blister beetles are polyphagous and found attracted to yellow and pink flowers.
Peak activity is usually from August-October.

Elytra are black in colour with a round orange spot and two wavy orange bands across the wings.
Eggs are usually laid in the soil and larvae feed upon soil insects, including major pests or on egg pods of various grasshoppers found in soil.

Adult beetles feed on flowers and tender pods, and may have a significant impact on yields, especially of short-duration genotypes.

Control

Adults can not be killed easily with the insecticides but synthetic pyrethroids work well.
Manual collection by hand picking or with an insect net and killing of adults in kerosenized water is the only possible solution, when population is alarmingly large.

9. Pod sucking bugs Anoplocnemis sp., Clavigralla Sp.

Adults of Anoplocnemis are brown or black, large in size with rounded shoulders.
Clavigralla are brownish grey with spine like projectious on shoulders.

Eggs are chocolate brown, bead like, laid in rows on leaves or pods.
Nymphs are shiny brown seen on developing pods.

Both nymphs and adults suck on developing seeds through pod wall.
The seeds become shriveled with dark parches and lose germination.

Control

Spraying of 700 ml trizophos 40 EC. Or Spray endosulfan 35 EC @ 2 ml/lit of water.
The above spray should be done by hollow cone nozzle and in 600 - 700 litre water/ha. 10.


Jassids Empoasca kerri
Adults are small green insects.
Nymphs are yellowish – green and almost translucent.
Eggs are inserted into the midrib.

Both nymphs and adults suck sap from under surface of the leaflets.
In heavy infestation, leaflets become cup-shaped and have yellow edges and tips.
Continued infestation result in leaflets turning red-brown followed by defoliation and reduced yield.

Control

Conserve predators like lady beetles, ants, chrysopa cymbela etc.
Conserve egg parasites like gonatocerus spp and oligosita sp.

In case of heavy infestation a single application of dimethoate can adequately reduce the population.

11.Aphids Aphis craccivora

Occurrence of aphids is seen in cooler months, after the cessation of rains and attacks a large number of leguminous crops.

The adults are black and shiny, about 2 mm long.
Both winged and wingless forms occur.

The nymphs are smaller, grey and dull due to waxy covering of body.
Females may lay the young ones which become adult in about a week due to which the population multiplies very fast.

Nymphs and adults colonize on young stem, leaves, flowers and pods.
Both adult and nymph suck the sap from young stem, leaves, flowers and pods and excrete honey dew.

Under heavy infestation, young leaves of seedlings become twisted; retard the pod development and grain formation.

Seedlings may wilt, particularly under moisture-stressed conditions.

Control

Heavy rains and coccinellid predators often discourage population build up in proportions which can cause economic damage.

If needed, spray of methyl dematon 25 EC at the rate of 300 ml/ha, the above spray should be done in 300 litre water/ha. or Spray phosphomidon 250 l/ha, the above spray should be done in 650 - 700 litre water/ha.

12. Cow bugs Otinotus oneratus , Oxyrachis tarandus
 
Adults are grey brown and have horn-like projections on the thorax.
Nymphs are lighter in colour
Eggs are laid in clusters of 15-20 on stems.

A close observation shows corky tissues and eggs in groups arranged roughly in the form of ‘V’.
Both nymphs and adults feed on tender shoots.

Cow bugs excrete honeydew, a sugary substance that attracts ants.
The ants may protect the bugs from natural enemies, which would otherwise keep cow bug populations in check.

Heavy infestation results in formation of corky tissues and reduced plant vigour.

Control
 
Because cow bug attacks are sporadic and do not generally cause any economic damage, no specific management strategies are suggested.

However, in situations contrary to this any systemic insecticide like dimethoate, methyl demeton or phosphamidon may be used.

13. Leaf webber Grapholita (Eucosma) critica

This is mainly a pest of redgram from seedling stage to reproductive stage.
Moth is small and dark brown.

Eggs are normally laid in clusters of about ten, on buds and young leaves.
Larva is cream-yellow in colour.

Pupation is in leaf web.
Larvae produce silk and use it to fold terminal leaves and web these together feed from inside the web of leaflets, flowers, and pods.

When infestation includes the terminal bud, further growth of that shoot may be severely impaired.
Infestations may begin as early as the seedling stage and continue through to the flowering and pod formation stages.

Control

Since the injury caused by the pest is of minor nature, use of chemicals is not warranted.
Removal and destruction of the spun leaves and the contained pest stages, and spraying with monocrotophos in case of high incidence is recommended.

14. Scale Ceroplastodes cajani

Distributed throughout India and mostly in South India.
Adult females are oval shaped, sedentary and remain attached to the stem and branches.

The scale insects are protected by waxy coating.

The first instar nymphs are active and after finding a suitable place on the host lose the appendages and there
after remain attached to the stem and branches.

Nymphs and adults suck sap and reduce vigour.
Severe infestation leads to dropping of leaves.

Control

The pest is usually not in a serious form, but if required any of the systemic insecticides can be used.

Integrated Pest Management in Red gram

Monitoring of pest incidence by community field scouting at periodic intervals should be undertaken to workout ETL.

Erecting light traps should be undertaken in the field.
Install pheromone traps at a distance of 50 m @ 5 traps/ha.

Use Helicoverpa lure and change it after every 20 days. Trapped insects should be removed and destroyed on daily basis.

Conservation of predatory spiders and wasps etc.

Installation of bird perches for the predatory birds.
Synchronize sowing with a single variety in a village/area.

Growing resistant / tolerant varieties.
Inter crop with Jowar for reducing Helicoverpa, wilt and nematode incidence.

Early planting ie in mid-June to avoid peak infestation period of H. armigera on short duration pigeon pea.
Planting of castor or tall sorghum / maize varieties on borders for conserving natural enemies. These plants also function as live perches for predatory birds.

Plant short stature pulse crops like cowpea, mungbean, urdbean, fodder soybean etc. in 1 m wide band after 8-10 rows of pigeon pea.

Growing trap crop like marigold on the borders and in between rows as inter crop as their flowers shall attract oviposition which can then be plucked and disposed.

Treatment of the seed with Trichoderma viride @ 4 grams/kg seed.
Seed treatment with carbendazim + thiram ( 1 gm + 2 gm/kg seed, or carbendazim (2 gm/kg seed) or thiram (3 gm/kg seed).

Application of NPV @ 250 LE per ha. on noticing eggs and 1st instars larvae (2-3 eggs or 1 larva per twigs). Spray of NSKE 5% at pre-flowering stage 3 times at 15 days interval.

Spraying of 0.07% endsulfan (2m1 of35 EC/lit of water) or 0.04% monocrotophos (1 ml of 36 SL/litre of water) or chlorpyriphos 20 EC @ 3.5 ml./1it. of water at 600-1000 lit of spray material per ha. with hand sprayer or 200-300 lit./ha with power sprayer.


Disease Management

The crop mostly suffers from wilt, stem rot and sterility mosaic diseases.

1. Wilt Fusarium udum

Wilt is the most destructive fungal disease of red gram. In Andhra Pradesh, it is prevalent in Telangana districts and Kurnool.

Red gram is susceptible to wilt pathogen throughout its development. But damage is greater during flowering and podding stage.

Yellowing of the leaves followed by partial or complete premature death of the plant is the main symptom.
Dark brown to purple band on the main and lateral branches extending upwards from ground black streaks under the bark.

Dark brown to black discoloration of the xylem in the stem and root regions.
The fungus survives on infected plant debris in the soil for about 3 years.
Growing resistant varieties like Maruti, Lakshmi, Durga, PRG-100, Mukta, Prabhat and Sharda can tolerate this disease.
Crop rotation of pigeon pea with sorghum, tobacco or castor every three years.
Intercropping or mixed cropping with sorghum.
Solarization of the field in summer to reduce the inoculums of the pathogen.

Soil application of 5kg of Trichoderma formulation/ha mixed with FYM can also be used to combat the disease.

Seed treatment with 4g Trichoderma viridae formulation + 2 g of vitavax or 3 gm thiram /kg of seed.
Seed dressing with carbendazim 50% + thiram 50% @ 3 g/kg of seed. or Seed treatment with carboxin + thiram (1:2) at the rate of 3g/kg of seed.


2. Phytopthora blight Phytopthora drechsleri

This is a devastating disease that kills young plants (1-7 week old) leaving large gaps in plant stand.
It causes seedlings to die suddenly as in damping off disease.
In infected plants water soaked, irregular lesions on the leaves often causing blighting of the leaf/leaflets and younger plant.

Infected leaves lose turgidity and become desiccated.
Brown sunken lesions on the stem and branches causing girdling and makes the infected stem weak and leads to breakage and drying of the plant/branches.
Root system is not affected.

Yield losses are usually higher in short duration types than in medium and long duration types.
The fungus survives as dormant mycelium in soil and in infected plant debris.
Cloudy weather and drizzling rain with temp 25 °C favor infection.
Low -lying areas where water stagnates, close spacing encourage blight build up.
Warm and humid weather following infection result in rapid disease development.

Control

Using resistant varieties like BDN1, ICPL 150, ICPL 288, ICPL 304 and KPBR 80-1-4
Seed treatment with 4 g Trichoderma viride formulation + 6 g metalaxyl (Apron) per kg of seed followed by spraying metalaxyl (Ridomil MZ) @ 2g / l help in reducing the disease incidence.
Avoid sowing red gram in fields with low lying patches that are prone to water logging.

3. Dry Root Rot Rhizoctonia bataticola, Macrophomina phaseolina
 
Dry root rot is a serious problem in late-sown or summer crops, and in perennial or ratooned pigeonpea.
In Andhra Pradesh, it is severe on red gram grown in Khammam, Krishna and Guntur districts.
Crop is more susceptible in the reproductive stage.
Infected plants suddenly and prematurely dry up. When such plants are uprooted their roots are rotten and shredded.

The finer roots are mainly affected and have dark, blackened streaks underneath their bark with evident dark sclerotial bodies. Such roots are brittle and break when touched.
Early symptoms are spindle-shaped lesions on stems and branches.
Hot (above 30°C) and dry weather encourages disease development.
Rain after prolonged dry spell pre-disposes the plant to the disease.
Symptoms usually appear at flowering and podding stages.
More severe on black soils than on red soils.

Control

LRG 66, ICPL 86005, ICPL 86020, ICPL 87105 and ICPL 91028 can tolerate this disease.
Seed treatment with 4 g Trichoderma viride formulation + 3 g Thiram per kg seed and application of 2 kg T. viride formulation mixed with 50 kg FYM per acre help in reducing the disese incidence.
Avoid water stress at flowering and podding.

4. Powdery Mildew Oidiopsis taurica , Leveillula taurica

White powdery fungal growth appears on the flowers and pods.
The initial symptoms develop as small chlorotic spots on the upper surface of individual leaves.
Subsequently the corresponding lower surfaces develop white powdery patches.
When the fungus sporulates, white powdery growth covers the entire lower leaf surface.
Severe infection leads to defoliation.
The disease cause stunting of young plants.
Cool, humid climate is congenial fungal infection.

Control

Spraying wettable sulphur @ 1g/litre. OR Triadimefon 25 @ 0.03% OR Carbendazim 0.5 g-1.0 g/lit effectively controls the disease.


5. Cercospora leaf spot Cercospora cajani, Cercospora indica

It is a problem in humid regions.
Small circular to irregular necrotic spots or lesions on older leaves coalesce when the weather is cool and humid leading to severe defoliation.
During epidemic lesions appear on young branches and their tips dry and die back.

Control

Spray Mancozeb @ 3g/litre of water or carbendazim 1 g/litre.


6.Alternaria leaf blight Alternaria tenuissima, Alternaria alternata

Symptoms develop as small, circular, necrotic spots on the leaves, and these spots gradually increase in size to characteristic lesions with dark and light brown concentric rings with a wary outline and purple margin.
The lesions appear on all aerial plant parts including pods causing blighting of leaves and severe defoliation and drying of infected branches.
The fungus sporulates well under warm, humid conditions.

Control
Resistant cultivars such as ICPL 366 and DA 2 are recommended.
Spraying Mancozeb @ 3g/litre of water reduces disease spread.


7. Rust Uredo cajani

Rust symptoms appear as dark brown raised pustules full of uredia on the lower leaf surfaces.
The infected leaves desiccate, and drop off.
Extensive defoliation when infections are severe.
Disease severity increases with the onset of flowering.

Dense planting, light rain, wind and cloudiness encourage disease development.
Light rain, wind and cloudiness encourage spore release, dispersal and disease development.

Control

Avoid sowing pigeon pea close to bean fields.
Crop rotation reduces the chance of pathogen survival.
Spraying Mancozeb @ 3g/litre of water reduces disease spread.


8. Botrytis gray mold Botrytis cinerea

Disease usually appears when plants are in flowering stage.
Dark gray fungal growth on the growing tips, flowers and pods.
Infected flowers drop, thus reducing pod set.
The shed flowers and leaves on the ground are covered with sporulating mycelium of the fungus.
It survives on infected debris and is better at 10°C.
It survives and remains ineffective up to 8 months in soil.

Control

Spraying chlorothalonil 3g/litre of water reduces disease spread.


9. Bacterial leaf spot and stem canker Xanthomonas campestris pv. cajani

It appears in rainy season during July and August.
Small necrotic spots on leaves surrounded by bright yellow hallow appear on the lower leaves of about 1 month old plants.
Later rough, raised cankerous lesions on stem resulting in their breakage.
Defoliation of lower leaves in severe case of infection.
In severe infestation, the affected branches dry.
Warm (25 – 30°C) and humid weather favour disease development.
Disease incidence is generally higher in low lying water logged areas of the field than in well drained areas.


Control

Spraying antibiotics like streptocycline 100 ppm @. 2.5 g/10 lit of water at 10 days intervals effectively controls the disease.


10. Sterility mosaic Sterility mosaic virus

Sterility mosaic is a serious problem in India which is transmitted by eriophid mite.
In the field, the disease can be easily identified from a distance as patches of bushy and stunted pale green plants without flowers or pods.

Mosaic pattern initially appear as vein clearing on the infected leaves of younger plants.
A single eriophid mite vector is sufficient to transmit the disease.
Perennial and volunteer pigeon peas and the rationed growths of harvested plants provide reservoirs of the mite vector and the pathogen.

Shade and humidity encourage multiplication of the virus.
ICPL 87119, ICPL 227, Jagruti and Bahar can tolerate the disease.

Spraying acaricide like dicofol 3ml / metasystox or kelthane @ 0.1% or sulphur 3 g in one litre of water to control mite vector in the early stages of plant growth is helpful.


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