Cowpea Cultivation Practices

COWPEA ( Vigna unguiculata (L.) Walp.aggreg.)

SEASON AND VARIETIES

DISTRICT/SEASONVARIETIES
Adipattam (June-August)
For all districts except Kanyakumari and NilgirisCo 6, Co(CP) 7, Paiyur 1, VBN 1
Purattasipattam (September - November)
Vellore, Thiruvannamalai, Dharmapuri, Salem, Namakkal, Perembalur, Erode, Coimbatore, Madurai, Dindigul, Theni and VirudhunagarCo 6, Co(CP) 7, Paiyur 1
Margazhi - Thaipattam (December – February)
Kanchipuram, Thiruvallur, Vellore, Thiruvannamalai, Dharmapuri, Salem, Namakkal, Coimbatore, Erode, Madurai, Dindigul, Theni, Tiruchirappalli, Perambalur, Ariyalur, Karur, Pudukkottai, Tirunelveli and ThoothukudiCo 2, Co 6, Co(CP) 7, VBN 2


PARTICULARS OF VARIETIES

Particulars

CO 2

Paiyur 1

CO 6

VBN 1

VBN 2

CO(CP) 7

ParentageHybrid derivative (C521 x C49)Selection from VM 16MS 9804 x 
C 152
Selection from 
T 85F 2020
Selection from IT 81-D-1228-10Gamma mutant of CO 4 (20  Kr)
Year of release197219851993199719982002
50% flowering(days)45753535 – 4040-4540 – 45
Duration (days)909065 – 7055 – 6575 - 8070 – 75
Grain yield(kg/ha) Rainfed...900671950-1000
Irrigated1375-----1600
Vegetable (Kg/ha)9400...- 10580-
Plant height (cm)30 - 4060 - 7034.525 - 3045 - 6040 – 55
Stem, branchesGreen stem purple wash at   nodes,
3-4 branches
ErectGreen stem purple wash   at nodes,   3-4 branchesErect green,
2 – 4 branches
Green erect,
2 – 3    branches
Green with purple ring at fruiting nodes,
5 – 8 branches
LeavesTrifoliate, broad and long petiolesDark green leaflets possessing tri­angular white spotsTrifoliate entire, green, purple spot at the abse of leafletLight greenDark green trifoliateOvote, trifoliate, entire, green and glabrous
Colour of podsTender greenish whiteGreenDark green pigmented tipGreenish whiteLight greenGreen
DryGreyish whiteBrown Brown at maturityCreamCreamLight brown
Colour of grainReddish brown with irregular patchesBrick redLight creamWhiteIvory white, hilum with tan ring surrounded by brown bandBrownish white and squire shape
100 grain wt (g)12.59.99.912 - 1513 - 1512 - 14


CROP MANAGEMENT

IV. MANAGEMENT OF FIELD OPERATIONS

1. FIELD PREPARATION

Prepare the land to fine tilth and form beds and channels.

SEED RATE

STRAINQuantity of seed required (kg/ha)
Pure cropMixed crop

Paiyur 1, VBN 1, VBN 2,  CO 6,  CO(CP) 7

25

12.5


Optimum plant population 3,50,000/ha. 

2. SEED TREATMENT

Treat the seeds with Carbendazim or Thiram 2 g/kg of seed 24 hours before sowing (or) with talc formulation of Trichoderma viride @ 4g/kg of seed (or) Pseudomonas fluorescens @ 10 g/kg seed.

  • Biocontrol agents are compatible with biofertilizers.
  • First treat the seeds with biocontrol agents and then with Rhizobium.
  • Fungicides and biocontrol agents are incompatible.


3. SEED TREATMENT WITH BIOFERTILIZER

  • Fungicide-treated seeds, should be again treated with a bacterial culture. There should be an interval of atleast 24 hours between fungicidal and biofertilizer treatments.
  • The improved rhizobial strain COC 10 is more effective in increasing the yield.
  • Treat the seeds with 3 packets (600 g/ha) of Rhizobial culture COC 10  and 3 packets (600 g/ha)  of Phosphobacteria developed at TNAU using rice kanji as binder. If the seed treatment is not carried out apply 10packets of Rhizobium (2000 g/ha)  and 10 packets(2000 g)  of Phosphobacteria with 25 kg of FYM and 25 kg of soil before sowing.   Dry the biofertilizer treated seeds in shade for 15 minutes before sowing.


4. FERTILIZER APPLICATION
    a)  Apply fertilizers basally before sowing.
         Rainfed : 12.5 kg N + 25 kg P2O5 + 12.5 kg K2O +10 kg S*/ha
         Irrigated : 25 kg N + 50 kg P2O5 + 25 kg K2O + 20 kg S*/ha
               *Note : Applied in the form of gypsum if Single Super Phospate is not applied as a source of phosphorus
            b)  Soil application of 25 kg ZnSo4/ha under irrigated condition     

5. SOWING

Dibble the seeds adopting the following spacing.

Varieties

Sole crop

Mixed crop

CO 6, VBN 1, Paiyur 130 cm X 15 cm200 cm X 15 cm
Co 6, CO (CP) 7, VBN 2, Co 245 cm x 15 cm..


Cowpea CO 6 at a spacing of 30cm X 15 cm


6. WATER MANAGEMENT

Irrigate immediately after sowing followed by life irrigation on the third day. Irrigate at intervals of 7 to 10 days depending upon soil and climatic conditions. Flowering and pod formation stages are critical periods when irrigation is a must. Avoid water stagnation at all stages. . Apply KCl at 0.5 per cent as foliar spray during vegetative stage if there is moisture stress.

7. SPRAYING OF DIAMMONIUM PHOSPHATE OR UREA,  NAA AND SALICYLIC ACID

  • Foliar spray of Spray of NAA 40 mg/litre and Salicylic acid 100 mg/litre once at pre-flowering and another at 15 days thereafter 
  • Foliar spray of DAP 20 g/litre  or urea 20 g/litre once at flowering and another at 15 days thereafter

8.WEED MANAGEMENT

  • Pre emergence application of Pendimethalin 2 litres on 3 days after sowing using Backpack/ Knapsack/Rocker sprayer fitted with flat fan nozzle using 500 l of water for spraying one ha. After this, one hand weeding on 30 days after sowing gives weed free environment throughout the crop period. 
  • If herbicides are not applied give two hand weedings on 15 and 30 days after sowing.

9.  Crop Protection

  • Pest of Cowpea

Gram pod borer: Helicoverpa armigera

Identification of the pest

  • Eggs – are spherical in shape and creamy white in colour, laid singly

  • Larva - shows colour variation from greenish to brown. Green with dark brown grey lines laterally on the body with lateral white lines and also has dark and pale bands.

  • Pupa – brown in colour, occurs in soil, leaf, pod and crop debris

  • Adult - light pale brownish yellow stout moth. Fore wing grey to pale brown with V shaped speck.Hind wings are pale smoky white with a broad blackish outer margin. 

Larva feeding the pod 

   Damaged pod

Symptoms of damage 

  • Defoliation in early stages
  • Larva’s head alone thrust inside the pods and the rest of the body hanging out.
  • Pods with round holes

Management

  • ETL: 10% of affected pods
  • Pheromone traps for Helicoverpa armigera 12/ha
  • Bird perches 50/ha
  • Mechanical collection of grown up larva and blister beetle
  • Ha NPV 3 x1012 POB/ha in 0.1% teepol
  • Apply any one of the following insectcides:
    • Azadirachtin 0.03 % WSP 2500-5000 g/ha
    • Bacillus thuringiensis serovar kurstaki (3a,3b,3c) 5%WP1000-1250 g/ha
    • Dimethoate 30% EC 1237 ml/ha
    • Emamectin benzoate 5% SG 220 g/ha
    • Indoxacarb 15.8% SC 333 ml/ha
    • Chlorantraniliprole 18.5 SC 150ml/ha
    • Spinosad 45%SC 125-162 ml/ha
    • NSKE 5% twice followed by triazophos 0.05%
    • Neem oil 2%
    • Phosalone 0.07%(Spray fluid 625 ml/ha) Note : Insecticide / Ha NPV spray.
Spotted pod borer: Maruca testulalis

 

Symptoms of damage 

  • Defoliation in early stages
  • Larva’s head alone thrust inside the pods and the rest of the body hanging out.
  • Pods with round holes

Identification of the pest

  • Larva - Greenish white with brown head. It has two pairs of dark spots on the back of each segment
  • Adult - Forewings- light brown colour with white markings; Hindwings – white colour with brown markings at the lateral edge

Management

  • ETL: 3/plant
  • Phosalone 0.07% (Spray fluid 625 ml/ha)Note : When the activity of coccinellid predator (both grubs and adults) is seen, insecticide application should be avoided.
Spiny pod borer: Etiella zinckenella

Symptoms of damage 

  • Dropping of flowers and young pods
  • Older pods marked with a brown spot where a larvae has entered
  • Larval – greenish initially, turns pink before pupation.
  • It has 5 black spots on the prothorax

Identification of the pest

Adult

  • Brownish grey moth 
  • Prothorax – orange in colour
  • Fore wing - has a white stripe along the anterior margin

Management

  • Conserve natural enemies like Tetrastichus sp., Bracon hebetor, Phanerotoma sp. and P. hendecasisella.
  • ETL 10% affected parts
  • Deep summer ploughing in 2-3 years to eliminate quiescent pupa.
  • Early sowing, short duration varieties.
  • Avoid closer plant spacing.
  • Grow tall sorghum as comparison crop to serve as biological bird perches
  • Collect and destroy larvae and adults to the extent possible
  • Install pheromone traps at a distance of 50 m @ 5 traps/ha for each insect pest.
  • Install Bird perches @ 50/ha.
  • Setting of light traps (1 light trap/5 acre) to kill moth population.
  • Control is achieved by releasing of Trichogramma chlionis at weekly intervals @1.5 lakh/ha/ week for four times.
  • Conserve green lacewing, predatory stink bugs, spider, ants
  • Application of NPV 250 LE /ha with teepol 0.1% and Jaggery 0.5% thrice at 10 – 15 days interval commencing from flowering stage. (Note: Insecticide / Ha NPV spray should be applied when the larvae are in early stage).
  • Bt @ 600 g, neem oil/ pungum oil 80 EC @ 2ml/lit
  • Spray NSKE 5% twice followed by triazophos 0.05%.
  • Apply any one of insecticides at 25 kg/ha quinalphos 4D, carbaryl 5D
  • Spray insecticide Quinalphos 25 EC @ 1000 ml/ha.
Blue butterfly: Lampides boeticus

Symptoms of damage 

  • Buds, flowers and young pods with boreholes
  • Presence of slug like caterpillar.
  • Honey dew secretion with black ant movements

Identification of the pest

  • Larva – It is flat and slightly rounded; Pale green with a rough skin.
  • Adult - moth is greyish blue with prominent black spots in the hind wings and a long tail; Ventral side of wings with numerous stripes and brown spots

 

Management

Spray any one of the following insectcides (Spray fluid 500 l/ha)

  • Emamectin benzoate 5%SG 220 g/ha
  • Indoxacarb 15.8%SC 333 ml/ha
  • NSKE 5% twice followed by triazophos 0.05%
  • Neem oil 2%
Grass blue butterfly: Euchrysops cnejus

Symptoms of damage

  • Buds, flowers and young pods with boreholes and presence of slug like caterpillar.
  • Larval entry hole on the pod is plugged with excreta.

Identification of the pest

  • Larva - pale green or yellow with a red line and short black hairs on the body.
  • Adult - butterfly is blue, medium sized with 5 black spots in the hind wings and two black spots in the inner margin.

 

Management of pod borer complex

  • ETL 10% affected parts
  • Deep summer ploughing in 2-3 years to eliminate quiescent pupa.
  • Early sowing, short duration varieties.
  • Avoid closer plant spacing.
  • Grow tall sorghum as comparison crop to serve as biological bird perches
  • Collect and destroy larvae and adults to the extent possible
  • Install pheromone traps at a distance of 50 m @ 5 traps/ha for each insect pest.
  • Install Bird perches @ 50/ha.
  • Setting of light traps (1 light trap/5 acre) to kill moth population.
  • Control is achieved by releasing of Trichogramma chlionis at weekly intervals @1.5 lakh/ha/ week for four times.
  • Conserve green lacewing, predatory stink bugs, spider, ants
  • Application of NPV 250 LE /ha with teepol 0.1% and Jaggery 0.5% thrice at 10 – 15 days interval commencing from flowering stage. (Note: Insecticide / Ha NPV spray should be applied when the larvae are in early stage).
  • Bt @ 600 g, neem oil/ pungum oil 80 EC @ 2ml/lit
  • Spray NSKE 5% twice followed by triazophos 0.05%.
  • Apply any one of insecticides at 25 kg/ha. quinalphos 4D, carbaryl 5D
  • Spray insecticides like Quinalphos 25 EC @ 1000 ml/ha.
Bean Aphids: Aphis craccivora    

Symptoms of damage

  • Leaves, inflorescence stalk and young pods  covered with dark coloured aphids
  • Honey dew secretion with black ant movements

Identification of the pest

  • Nymphs and Adult – dark coloured with cornicles in the abdomen

Management

Spray any one of the following insectcides (Spray fluid 500 l/ha)

  • Emamectin benzoate 5%SG 220 g/ha
  • Indoxacarb 15.8%SC 333 ml/ha
  • NSKE 5% twice followed by triazophos 0.05%
  • Neem oil 2%


Nymphs and Adults

Leaf hopper: Empoasca kerri

Symptoms of damage

  • Leave mottled and yellowish in colour
  • Green colour insects found under surface of leaves

Identification of the pest

  • Adult – elongate, active, wedge shape, green insects

Management

Spray the infested crop with methyl-o- demeton 750 ml in 700 - 1000 L water per hectare

Pod bugs:  Riptortus pedestris

Symptoms of damage

  • Pods with black spots
  • Shedding of green pods
  • Poorly filled pods with shriveled grains inside

Identification of the pest
Riptortus pedestris

  • Brownish black and hemispherical 
  • Nymphs – resemble dark brown ants

Management:

  • Dimethoate 30% EC 500ml/ha
  • Methyl demeton 25%EC 500ml/ha
  • Imidacloprid 17.8 SL 100-125 ml/ha
  • Thiamethoxam 25% WG 100 g/ha
Lab lab bug or Stink bug: Coptosoma cribraria

Symptoms of damage

  • Cluster on the  plant  parts and suck the sap

Identification of the pest

  • Nymphs and Adult - sub globular, oval and greenish shield bug.
  • It has a characteristic buggy odour
Whitefly: Bemisia tabaci

Symptoms of damage

  • Pods with black spots
  • Shedding of green pods
  • Poorly filled pods with shriveled grains inside

Identification of the pest
Riptortus pedestris

  • Brownish black and hemispherical 
  • Nymphs – resemble dark brown ants

Management:

  • Dimethoate 30% EC 500ml/ha
  • Methyl demeton 25%EC 500ml/ha
  • Imidacloprid 17.8 SL 100-125 ml/ha
  • Thiamethoxam 25% WG 100 g/ha
Blister beetle: Mylabris phalerata

Symptoms of damage

  • The adult feeds voraciously on buds and flowers.

Identification of the pest

  • Eggs - are light yellowish in colour and cylindrical in shape.
  • Larvae - Young grubs are white in colour.
  • Adult – Elytra are black in colour with a round orange spot and two transverse wavy   orange bands across the wings.

Management

  • Manual collection or collection with insect net and killing of adults in kerosenized water appears to be the only possible solution.

Diseases of Greengram

Root rot and Damping off: Pythium, Rhizoctonia, Macrophomina

Symptom
  • Symptoms vary and include rapid death of young succulent plants.
  • Discoloration of taproots, longitudinal cracks of the stems, stunting, wilting and poor yields.
  • Complete control of root rot and damping off is difficult, and no variety of cowpea is resistant to root rot.
  • Persistent damp weather prior to development of the first true leaf and also the crowding of seedlings due to poor seed spacing may increase damping off.
  • Management
  • Soil application P. fluorescens or T. viride– 2.5 kg / ha + 50 kg of well decomposed FYM or sand
  • Spot drenching with Carbendazim @ 1 gm/ litre

Southern blight: Sclerotium rolfsii

Symptom
  • Southern blight is caused by a fungus that attacks roots and stems of cowpeas.
  • The first visible symptom of southern blight is a progressive, yellowing and wilting of the foliage beginning on the lower leaves.
  • The plant dies within a few days.
  • A brownish vascular discoloration inside dead stem may extend several inches above the soil line.
  • During warm, moist conditions, the coarse, white mycelium of the fungus makes characteristic fan-shaped patterns of growth on the stem at the soil line.
  • In this white-mat of the fungus, numerous smooth, round, light-tan to dark-brown mustard seed-like bodies called sclerotia are formed.

Cowpea mosaic: Virus

Symptom
  • Symptoms vary and include rapid death of young succulent plants.
  • Discoloration of taproots, longitudinal cracks of the stems, stunting, wilting and poor yields.
  • Complete control of root rot and damping off is difficult, and no variety of cowpea is resistant to root rot.
  • Persistent damp weather prior to development of the first true leaf and also the crowding of seedlings due to poor seed spacing may increase damping off.

Management

  • Roguing out of cowpea mosaic virus diseased plants in the early stage of growth up to 30 days and spraying twice at fortnightly intervals with Monocrotophos 500 ml/ ha (or) Methyldemeton 25 EC 500 ml/ha.

Fusarium wilt: Fusarium oxysporum

Symptom

  • Fusarium wilt usually causes the lower leaves on one side of the plant to turn yellow.
  • Infected plants usually are stunted and wilted as the organism develops in the food and water conducting tissues.
  • Brick red tissue can be observed in the stem when it is split lengthwise.

Management

Fungal and viral diseases can be reduced by:

  • Treating high quality seed with fungicides labeled for cowpeas.
  • A four or five year rotation with other crops.
  • In addition to the cultural practices listed above, bury previous crop debris and the sclerotia, to control Southern blight at least 6 inch deep as far ahead of planting as possible.
  • Seeding into warm, well-prepared soils.
  • Planting certified seed of resistant varieties.
  • Controlling weeds.
  • The removal of virus-affected plants.
  • Spray any one of the systemic insecticide like Monocrotophos @0.1% to control the vector.
  • When resistant varieties are not used, it is important that root-knot nematode control practices be followed since nematodes increase plant susceptibility to Fusarium wilt.

Post Harvest Technology 


Pulses constitute essential components of vegetarian diet. Pulses are major source of protein in Indian vegetarian diet. These are main source of protein providing most of the essential amino acids to a certain degree. Economically, pulses are cheapest source of protein. Pulses are Bengal gram, pigeon pea, black gram, green gram, lentil, etc. Pulses are mainly consumed in the form of dehusked split pulses, as these are rich in proteins. In vegetarian diet pulses are main source of protein.

COMPOSITION :Green gram, red gram, bengal gram, horse gram, cluster bean, field bean, cow pea are some of the common types of pulses.In general, their protein content is high and is commonly more than twice that of cereal grains, usually constituting about 20 per cent of the dry weight of seeds. The protein content of some legumes like soyabean is as high as 40 per cent.

NUTRITIVE VALUE OF PULSES

 Energy
Kcals
Moisture
g
Protein
g
Fat
g
Mineral
g
Carbohydrates  gFibre
g
Calcium
mg
Phosphorus
mg
Iron
mg
Bengal gram, whole360101753442023125
Bengal gram, dhal37210216311563315
Bengal gram, roasted36911225211583409
Black gram, dhal347112413111543854
Cow pea32313241334774149
Field bean, dry34710251311604333
Green gram, whole334102413441243264
Green gram dhal34810241311754054
Horse gram, whole321122203552873117
 Kherasi dhal345102812572903176
Lentil343122512591692937
Moth beans3301124135642022309
Peas green9373701164201391
Peas dry315162012564752987
Peas roasted340102312594813456
Rajmah34612231361      5    2604105
Redgram, dhal335132223581733043
Redgram tender116651011176571641
Soyabean43284319421424069010

Pulse seeds are also sources of other nutritionally important materials, such as vitamins and minerals.

Carbohydrates: Food pulses contain about 55-60 per cent of total carbohydrates including starch, soluble sugars, fibre and unavailable carbohydrates.

Minerals: Pulses are importantly sources of calcium, magnesium, zinc, iron, potassium and phosphorus.

Vitamins: Pulses contain small amounts of carotene, the provitamin A.

TOXIC CONSTITUENTS OF PULSES : The seeds of pulses include both edible and inedible types. Even amongst the edible legumes toxic principles occur and their elimination is important in order to exploit them for edible purposes. Two thermoliable factors are implicated in toxic effects. Inhibitors of the enzymes trypsin, chymotrypsin and amylase haemagglutinins, which impede the absorption of the products of digestion in the gut. In addition, legumes also contain a goitrogen, a toxic saponin, cyanogenic glycosides and alkaloids.

Elimination of Toxic Factors :  It has already been indicated that soaking, heating and fermentation can reduce or eliminate most of the toxic factors of the pulses. Correct application of heat in cooking pulses can eliminate most toxic factors without impairment of nutritional value. Cooking also contributes towards pulse digestibility. Heat causes the denaturation of the proteins responsible for trypsin inhibition, haemagglutination and the enzyme responsible for the hydrolysis of cyanogenic glycosides. The mode of application of heat is important. Autoclaving and soaking followed by heating are effective. Another way of eliminating toxic factors is by fermentation, which yields products more digestible and of higher nutritive value than the raw pulses.

PROCESSING

Processing: Processing of pulses is of primary importance in improving their nutritive value. The processing methods used are soaking, germination decortications, cooking and fermentation.

Soaking: Soaking in water is the first step in most methods of preparing pulses for consumption. As indicated above, soaking reduces the oligosaccharides of the raffinose family. Soaking also reduces the amount of phytic acid in pulses.

Germination: Germination improves the nutritive value of food pulses. The ascorbic acid content of pulses increases manifold after 48 hours germination. Germinated and sprouted pulses have been used to prevent and cure scurvy. The riboflavin, niacin, choline and biotin contents of all pulses increase during germination. The germination process reduces and/or eliminates most of the antinutritional and toxic factors in several pulses.

Decortication: A simple method is to soak the seeds for a short time in water; the husk takes up more water than the seeds and may be easily separated by rubbing while still moist. In the alternative, the soaked grains may be dried and the husk removed by pounding and winnowing. Roasting also renders the husk easier to separate. Roasted legumes like those of Bengal gram and peas are widely used in India.

Cooking: Cooking destroys the enzyme inhibitors and thus improve the nutritional quality of food pulses. Cooking also improves the palatability.

Fermentation: The processing of food pulses by fermentation increases their digestibility, palatability and nutritive value. Fermentation process improves the availability of essential amino acids and, thus, the nutritional quality of protein of the blend. In general, the nutritive value of the legume based fermented foods has been shown to be higher than their raw counterparts.

Pulse milling : Pulses are usually converted into Dhal by decutilating and splitting. Both dry and wet milling processes are employed. By and large carborundum emery rollers are used for dehusking and burr grinders for splitting. Decuticling is seldom complete in single pass requiring multiple passes, each pass producing 1.5 to 2% fines reducing recovery of dal.

Basic processes in dhal milling are cleaning, dehusking, splitting, separation and bagging. Major variation is involved with dehusking process only. Dhals like Arahar, urad, moong and lentil are difficult to dehusk as a result repeated operations by dehusking rollers are required. Rewetting and drying is done to loosen portions of husk sticking after repeated rolling. Linseed oil is used to impart shine or better appeal to the milled dal.

The removal of the outer husk and splitting the grain into two equal halves is known as milling of pulses. To facilitate dehusking and splitting of pulses alternate wetting and drying method is used. In India trading milling methods produce dehusked split pulses. Loosening of husk by conditioning is insufficient in traditional methods. To obtain complete dehusking of the grains a large number of abrasive force is applied in this case as a result high losses occur in the form of brokens and powder. Yield of split & pulses in traditional mills are only 65 to 75% due to the above losses compared to 82 to 85% potential yield.

Milling of Pulses : In India, there are two conventional pulses milling methods ; wet milling method  and dry milling method. The latter is more popular and used in commercial mills.Traditional dry milling method ('DHAL'  MILLING) : There is no common processing method for all types of pulses. However, some general operations of dry milling method such as cleaning and grading, rolling or pitting, oiling, moistening, drying and milling have been described in subsequent paragraphs.

Cleaning and grading : Pulses are cleaned from dust, chaff, grits, etc., and graded according to size by a reel type or rotating sieve type cleaner.

Pitting : The clean pulses are passed through an emery roller machine. In this unit, husk is cracked and scratched. This is to facilitate the subsequent oil penetration process for the loosening of husk. The clearance between the emery roller and cage (housing) gradually narrows from inlet to outlet. As the material is passed through the narrowing clearance mainly cracking and scratching of husk takes place by friction between pulses and emery. Some of the pulses are dehusked and split during this operations which are then separated by sieving.

Pretreatments with oil : The scratched or pitted pulses are passed through a screw conveyor and mixed with some edible oil like linseed oil (1.5 to 2.5 kg/tonne of pulses). Then they are kept on the floor for about 12 hours for diffusion of the oil.

Conditioning of pulses : Conditioning of pulses is done by alternate   wetting   and drying. After sun drying for a certain period, 3-5 per cent moisture is added to the pulse and tempered for about eight flours and again dried in the sun. Addition of moisture to the pulses can be accomplished by allowing water to drop from an overhead tank on the pulses being passed through a screw con­veyor. The whole process of alternate wetting and drying is continued for two to four days until all pulses are sufficiently conditioned. Pulses are finally dried to about 10 to 12 per cent moisture content.

Dehusking and Splitting : Emery rollers, known as Gota machine are used for the dehusking of conditioned pulses About 50 per cent pulses are dehusked in a single operation (in one pass). Dehusked pulses are split into two parts also, the husk is aspirated off and dehusked, split pulses are separated by sieving. The tail pulses and unsplit dehusked pulses are again conditioned and milled as above The whole process is repeated two to three times until the remaining- pulses are dehusked and split.

Polishing: Polish is given to the dehusked and split pulses by treating them with a small quantity of oil and / or water.

Commercial milling of pulses by traditional methods

The traditional milling of pulses is divided into two heads, namely, dry milling and wet milling. But both the processes involved two basic steps : (i) Precon­ditioning of pulses by alternate wetting and sun drying for loosening husk and (ii) subsequent milling by dehusking and splitting of the grains into two cotyledons followed by aspira­tion and size separation using suitable machines.  100 per cent-dehusking and splitting of pulses are seldom achieved particularly in cases of certain pulses like Red gram, black gram and green gram. Of them Red gram is the most difficult pulses to dehusk and split. Only about 40 to 50 per cent Red gram grains are dehusked and split in the first pass of preconditioning and milling. As sun drying is practiced the traditional method is not only weather dependent but also it requires a large drying yard to match with the milling capacity. As a result it takes 3 to 7 days for complete processing of a batch of 20 to 30 tonnes of pulses into dhals. Moreover milling losses are also quite high in the traditional method of milling of pulses. 

In general, simple reciprocating or rotary sieve cleaners are used for cleaning while bucket elevators are used for elevating pulses.

Pitting or scratching of pulses is done in a roller machine. A worm mixer is used for oiling as well as watering of the pitted pulses.

Blowers are used for aspiration of husk and powder from the products of the disc sheller or roller machine. Split dhals are separated from the unhusked and husked whole pulses with the help of sieve type separators.
Sieves are also employed for grading of dhals.

In general, the raw pulses may contain 2 to 5 per cent impurities (foreign materials), some insect infested grains and extra moisture.   Though the clean pulses contain about 10-15 percent and 2-5 per cent germs, the yield of dhals commercial dhal mills varies   from  68-75   per  cent.    It may be noted that the average potential yields of common dhals vary from 85 to 89 per cent.  These milling losses in the commercial pulses mills can be attributed lo small brokens and fine powders found during scoring and simultaneous dehusking and splitting operations.

VALUE ADDITION

Value added Products from Pulses Roasting of Pulses Preparation of Papad Soyabean Milk TOFU (Soy Panner)
   Puffing of Soyabean Preparation of Khakara & Soy Chocolate Processing of soymilk paneer 
Instant Food Mix Dehydrated Paneer Mix Preparation of Pakoda Mix Preparation of Instant Adai Mix Preparation of instant vada mix
   Preparation of instant bajji mix Kuruma Powder Mix, Idli Podi, Paruppupodi  
Extruded Products    
Bakery Products