The pigeon pea (Cajanus cajan) is a perennial legume from the family Leguminaceae (Fabaceae). It is also known as Pigeonpea or Arhar or Tur. Since its domestication in India at least 3,500 years ago, its seeds have become a common food grain in Asia, Africa, and Latin America. It is consumed on a large scale mainly in south Asia and is a major source of protein for the population of that subcontinent.

Origins and history:

1. The cultivation of the pigeon pea goes back at least 3,500 years.

2. The centre of origin is probably peninsular India, where the closest wild relatives (Cajanus cajanifolia) occur in tropical deciduous woodlands.

3. Archaeological finds of pigeon pea dating to about 3400 years ago (14th century BC) have been found at Neolithic sites in south India (Sanganakallu) and its border areas (Tuljapur Garhi in Maharashtra and Gopalpur in Orissa).

4. From India it traveled to East Africa and West Africa. There, it was first encountered by Europeans, so it obtained the name Congo Pea.

5. By means of the slave trade, it came to the American continent, probably in the 17th century.

Geographical distribution

1. Pigeonpea is grown in over 50 tropical countries of the world especially in more arid regions of Africa, Asia and the Americas.

2. In India, it is cultivated as an annual crop, but in other countries, it is grown as perennial crop, where pods are harvested at regular intervals.

3. Red gram is mainly cultivated and consumed in developing countries of the world.

4. The major pigeonpea producing countries of world are India Myanmar Kenya Malawi Uganda and Tanzania.

5. Pigeonpea is the second most important pulse crop in the country.

6. India is the largest producer and consumer of Red gram in the world.

7. India accounts for over ¾ of acreage and production of the globe.

8. The crop is extensively grown in Maharashtra, Andhra Pradesh and Gujarat.

9. Maharashtra has unique distinction of contributing about 30% of total pigeonpea production in the country

(Source: ICAR, IIPR, 2014-15)

Importance:

1. Red gram is a protein rich staple food.

2. It contains about 22 percent protein, which is almost three times that of cereals.

3. Red gram supplies a major share of protein requirement of vegetarian population of the country.

4. Red gram is mainly consumed in the form of split pulse as dal, which is an essential supplement of cereal based diet.

5. The combination of dal-chawal (pulse-rice) or dal-roti (pulse-wheat bread) is an important ingredient in the average Indian diet.

6. The biological value improves greatly, when wheat or rice is combined with Red gram because of the complementary relationship of the essential amino acids.

7. It is particularly rich in lysine, riboflavin, thiamine, niacin and iron.

8. Nutritional value of edible portion per 100 g of Red gram:

Botany:

Pgeonpea (Cajanus cajan L.), a diploid legume crop species (2n = 2x = 22), is a member of the tribe Phaseoleae. Pegion pea belongs to family Leguminoseae. It is an erect shrub. The plant show considerable variations in height, ranging from 1-4 meters. In most of the types branching begins from the sixth to the tenth node, i.e. from 15-20 centimeters above the ground.

The botanical description of main parts of pigeon pea plant is given below:
a. Root system
1. Root system of pigeon pea consists of a central tap root with numerous lateral and secondary branches.

2. The length of the lateral roots differs with the variety; usually tall, upright varieties produce longer and more deeply penetrating roots, whereas spreading types produce shallower, more spreading and deeper roots.

b. Leaves
1. Leaves are trifoliately compound; central leaflet longer than lateral ones.

2. The leaflets are entire and densely silky on the lower surface.

3. Stipules are small; lamina hairy with the under surface grayish due to dense hairs.

4. The total length of the leaf, as also the size, shape and texture of leaflets also differ with the varieties.

c. Inflorescence
1. The inflorescence is an axillary raceme often forming a terminal panicle.

2. The size of inflorescence varies in different types.

3. The flowers are distinctly papallionaceous.

4. In the late maturing varieties, the flowers are usually grouped together at the ends of the branches, but in early maturing varieties, the flowers are produced at several points along the branches.

5. Usually flowers open at a time on the same inflorescence, but the process of flowering continuous in each plant almost up to the time of harvest.

6. The flowers are self pollinated, pollination takes place before the flowers open.

7. Cross fertilization may also occur to some extent.

d. Pods
1. The fruit of pigeon pea is a pod.

2. These vary in length, width and nature of markings.

3. The length of pod varies from 5 to 10 centimeter, width from 0.6 to 0.9 centimeter.

4. The pods vary in color from green to dark brown.

5. In some types, they are broad and pendant with their tips pointing downwards while in others they are quiet erect.

6. The seed in the pod may vary in number, but there are usually four to five in each pod in late maturing varieties and two to three in early maturing varieties.

e. Seeds
1. Seeds are differing in great deal in size, shape and color.

2. Seeds are round or lens shaped, the color of the seeds coat being dirty white to silver white, light brown to chestnut brown, dark mottled brown and pinkish black and the cotyledons yellow colored.

Climatic requirement (Ecology):

a. Climate
1. Pigeonpea is predominantly a crop of tropical areas mainly cultivated in semi-arid regions of India.

2. Pigeonpea can be grown between 14°N and 28°N latitude, with a temperature ranging from 26° to 30°C in the rainy season and 17° to 22°C in the post rainy season.

3. The amount of daily global solar radiation varies from 400 to 430 cal cm day in the rainy season and 380-430 cal cm-2 day-1 in the postrainy season.

4. Mean annual rainfall ranges from 600 to 1400 mm, of which 80%-90% is received in the rainy season.

5. The length of growing season extends from 120 to 180 days.

6. Pigeonpea is very sensitive to low radiation at pod development, therefore flowering during the monsoon and cloudy weather, leads to poor pod formation.

b. Soils
1. In India, pigeonpea is cultivated on Entisols, Alfisols, Enceptisols, and Vertisols.

2. The Entisols found in the alluvial- soil belt of the Indo-Gangetic region are deep loams, slightly alkaline (pH 7.5-8.5), with about 150-200 mm available water storage capacity in 2 m of soil.

3. The Vertisols are characterized by 40-60% clay in the surface soil horizons, pH around 8.0 with a water holding capacity between 150-300 mm, and the available water in the top 1.5-2.0 m of soil.

4. Alfisols are neutral in reaction (pH 6.5-7.0) and relatively shallow with low-clay content.

5. They are often sandy loam and can retain about 100 mm available water in the root profile. Pigeonpea, being sensitive to water logging, requires a well-drained soil.

6. It does not grow well in saline soil, but can withstand drought reasonably well.

7. Responses to lime indicated by increase in shoot growth and nodulation, have been reported in soils with pH below 5.0.

Land preparation:

1. Good land preparations are necessary for better yield of red gram.

2. Land should be ploughed in summer followed by two to three harrowing at pre-monsoon for kharif season.

3. Land should be well leveled.

4. Collect the weeds, previous crops stubbles, stones and clean the field for sowing.

5. Mix five to six tons of FYM or compost at last harvesting.

6. If necessary, one pre-sowing irrigation should be given.

Sowing:

a. Selection of seed:
1. Seed should be free from insect, pest and diseases.

2. It should be free from any inert matter i.e. dust particles, weed seeds etc.

3. It should be purchased from Agril. Research station, universities, KVK’s and registered seed companies /Agri. Service centers/Agriclinics.

4. Seeds should be viable and genetically pure.

b. Method of sowing:
1. Sowing should be done in line sowing\drilling method with tractor drawn ferti-cum-seed drill or by bullock drawn ferti-cum-seed drill/tifan.

2. Seed can be sown in dibbling method with hand dibbler to maintain optimum plant stand and higher productivity.

3. Ferti-cum-seed drill should be used for the application of fertilizers and seed sowing at a time.

4. Seeds should not be sown more than 5 to 6 cm in depth.

c. Time of sowing:
1. In the rainfed and dry areas pigeon pea are sown with the onset of the monsoon.

2. Earlier sowing gives higher yields in India.

3. When sowing extra - early and early - maturing varieties in the 1st fortnight of June , the field is available for post rainy season crops by the end of November. Therefore , sowing should not be delayed beyond June.

4. The sowing of medium and late-maturing varieties , under rainfed conditions , should be done during June or July at the onset of the monsoon. This should be preferably before the 2nd week of July.

5. Late sowing causes considerable reduction in yield due to photoperiodicity and excessive soil moisture stress which coincides with the reproductive growth. The post rainy season sowing in India should be done in September.

6. In sowings later than 15 October, yields drastically decline.

d. Seed treatment:
1. Seed should be treated with thiram @ 1.5 to 2 g / kg seed

2. ICRISAT recommend seed treatment with 3 g thiram/kg + 3 g carbendazim/kg seed.

3. It should be treated with rhizobium culture for atmospheric N fixation.

e. Seed rate and spacing
1. Seed should be own behind the plough or with the help of seed drill at a row spacing of 60-75 cm keeping 15-20 cm distance from plant to plant.

2. A seed rate of 12-15 kg per hectare is sufficient.

3. In mixed cropping seed rate is adjusted according to the proportion of arhar and companion crops to be grown.

4. In the intercropping seed rate remains same as for pure crops.

Varieties:

Some of the important varieties of pigeon pea released in India for the different maturity groups are given below:

Extra-short-duration varieties of pigeonpea released in India:

Short-duration varieties of pigeonpea ralaasad in India:

Medium-duration varieties of pigeonpea developed in India:

Late-duration varieties of pigaonpaa ralaaaad in India:

Fertilizer management:

Apply fertilizers basally before sowing as per following dose:
Rained : 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

Irrigation management:

1. Red Gram requires 35-40 cm water, during its entire growth period.

2. Optimum moisture is necessary during (a) budding (b) flowering and (c) pod formation stages.

3. As red gram is a rainfed crop grown in assured rainfall areas, usually it does not require any irrigation. If there is water stress, protective irrigation may be given in alternate rows at these 3 stages.

Weed management:

1. It is necessary to keep the crop weed-free during the early growth period (4-6 weeks).

2. Pre emergence application of prometryn (Gesgard® or Caparol® a.i. 1.25 kg ha- 1) effectively controlled the initial weeds.

3. A hand weeding 3-4 week after sowing is required to remove the late emerging weeds.

4. When herbicide is not applied, two or three hand weedings are required from the 1st to 6th week of crop growth.

5. Hand weedings were always found superior to herbicides, but the herbicides were more economical, hence preferred.

6. The other pre emergence herbicides effective for pigeonpe a are pendimethalin (Stomp® a.i. 1.0-1.5 kg ha- 1) or meta chlore (Dual® a.i. 1 kg ha-1).

7. The post emergence herbicides recommended are flausifop-P butyl (Fusilate® a.i. 0.2-0.4 kg ha-1) or bentazon (Basagran® a.i. 1.0 kg ha- 1) at 2-4 leaf stage.

Disease and insect pest control:

Diseases:

Inter-cropping

• Raising one row of long duration redgram varieties as inter crop for every six rows of groundnut (6:1) is recommended for rainfed crops.

• Raising one row of short and medium duration redgram as inter crop for every four rows of groundnut (4:1) is recommended for rainfed as well as for irrigated crops.

• Multistoreyed cropping: For rainfed Vertisols of Virudhunagar, Tirunelveli, Thoothukudi districts recording more than 300 mm of rainfall during the crop growth period, multistoreyed cropping system Agathi + Redgram (CO 5) + Cotton (MCU 10) + Blackgram (CO 5) is highly profitable. (Agathi in I tier with 1 x 1 m spacing - Redgram in II tier with a spacing of 45 x 20 cm - Cotton in the III tier with a spacing of 45 x 15 cm - Blackgram in the IV tier with the spacing of 30 x 10 cm).

For rainfed Vertisols receiving less than 300 mm of rainfall, Agathi + Sorghum (CO 26) + Cotton (MCU 10) + Blackgram (CO 5) system is ideal. For both systems, apply 40 kg N and 20 kg P2O5/ha. (Agathi in I tier with a spacing of 1 x 1 m - sorghum in II tier with a spacing of 45 x 15 cm - cotton in III tier with the spacing of 45 x 15 cm and Blackgram in IV tier with 30 x 10 cm).

Redgram Transplanting

• Select only long duration redgram varieties

• Transplant within the month of August either under rainfed condition or under irrigated condition

• Select poly bag with a size of 6x4 inches and 200 micron thickness

• Fill the poly bag with native soil: Sand: FYM @1:1:1 and put 3-4 holes in the bottom to avoid water stagnation

• Soak the seeds in 0.2% Calcium chloride for one hour and dry it under shade for 7 hours to harden the seeds

• Treat the hardened seeds with T. viride @ 4g/kg and 100 g Rhizobium and 100 g phosphobacterium. Sow the seeds @2/poly bag at 1 cm depth

• Sow the seeds in polybags 30-45 days prior to transplanting

• Plough the field deeply to get fine tilth followed by 2-3 harrowings at 3 weeks prior to transplanting

• In medium to deep soils for raising long duration varieties, dig 15 sqcm pits at 5’ X 3’ for pure crops and 6’ x 3’ for intercropping under irrigated condition. In rainfed condition dig the pits at a spacing of 5’x3’. For short duration varieties dig 15 sq cm pits at 3’ x 2’ spacing.

• Under water logging condition, form furrows before digging pits

• Apply inorganic fertilizers @ 25:50:25 kg NPK /ha at 20-30 days after planting as urea, DAP and potash around the seedlings

• Apply ZnSO4 @ 25 kg/ ha as basal along with FYM or sand

• Nip (removal of top 5 cm) the plants at 20 – 30 days after planting to arrest the terminal growth

• Spray planofix @ 0.5 ml/litre to control flower dropping

Signs of maturity, harvesting & threshing

Pods and plant dried, Grains become hard, and moisture percent in grain at harvesting should be 20-22 %. Pod shattering is common problem in pulse. Harvest the whole plants with sickle when 80% of the pods mature. The pods or whole crop after complete drying should be threshed manually or by machine.