Black gram
Black gram is one of the important grain legumes in the rain fed farming system in dry and intermediate zones of Sri Lanka. It can be grown under low moisture and fertility conditions. It has high nutritive value and consist high content of proteins, vitamins and minerals.
Presently, black gram is successfully cultivated in the districts of Anuradhapura, Polonnaruwa, Vavuniya, Kurunegala, Puttlam, Killinochchi, Mulathiv, Batticaloa and Jaffna. About 80% of black gram crop cultivated during maha season as rain fed uplands crop and rest is grown in yala in paddy fields with supplementary irrigation. Cultivated extent and production of black gram vary from year to year with a decreasing trend (Table 01). Consequently, the production is not sufficient for the demand. The national average yield of black gram has been stagnating around 0.7-0.8 t/ha over the years, and it is far behind the research yield, which is about 1.5-2.0 t/ha. Until early nineties large quantities of black gram were exported to various countries and no importation were recorded. However, recent figures illustrates that the large quantities of black gram are imported annually (Table 01).
Extent, production and import data of black gram in last five years

Year

Extent (ha.)

Production (mt.)


Imports (mt.)


1997

8782

6844

1659

1998

10171

8049

677

1999

8658

6730

5640

2000

6703

5420

7331

2001

6361

5125

7890



Source: Economics division, DOA

Nutritional value of black gram
Black gram is one of the rich sources of vegetable protein and some essential minerals and vitamins for the human body
(table 02).
Approximate analysis of nutrients in 100g of edible portion of black gram

Component

Amount

Protein ( %)

20-25

Fat (% )

1.3

Ash (%)

3.40

Crude fiber ( %)

4.2

Starch ( %)

40 - 47

Vitamins

Vitamin A (IU)

300

Vitamin B1 (mg / 100g )

0 .52- 0.66

Vitamin B2 (mg / 100g )

0.29 - 0.22


Niacin ( mg / 100g )

2.0

Vitamin C ( mg / 100 g )

5

Minerals

Iron (mg / 100g )

7.8

Calcium (mg / 100g )

145



Source : AVRDC,
Recommended Varieties

Variety

MI - 1

Year of recommended

Before 1965

Special characters

Days to maturity

80-90

Seed shape

Faily cylindrical

1000 Seed wt.( g )

56

Seed colour

Black


Average yield ( t / ha)

2.5

Pest and Diseases

Mungbean Yellow Mosaic Virus(MYMV)

Moderately susceptible

Cercospora leaf spot

Susceptible

Powdery mildew

Susceptible

Insect pest

Bruchids

Moderately

susceptible



Field Establishment

Environmental /growth requirement
Prefer dry whether condition, Optimum T between 25 C - 35 C Maturity period should be coincide with the dry whether condition for high yield and quality seeds (this is one of the criteria to decide time of planting)

Optimum soil requirement pH 6-7
Well drained sandy to loam soil
Suitable Climatic Zones Dry & intermediate
Suitable cropping systems Can successfully incorporate in to the different types of cropping
systems.

1. Rain fed uplands - maha / yala Mono culture
Intercropping: eg. Maize + blackgram
2. Rain fed lowlands yala Mono culture Intercropping
3. Major irrigation schemes - yala -Rice- legume system.
Black gram can be grown as a relay crop before the on set of yala rains
or with rainfall during yala season.
4. Minor irrigation schemes - yala
5. Under agro well -yala

Land preparation Plough and harrow the land. Make ridges or flat beds according to the water supply

Seed rate MI-1 - 30 kg/ha

Planting method Put 2 seeds/hill and thin out weaker plant after 10-12 days
Space between rows - 30-40 cm ( 12 "- 16" )
Between plant in a rows - 10cm ( 2 ?- 3")
Depth of seeding - 1-1.5cm
Best time for cultivation Maha (wet) season - mid September to October
Yala (dry) season - March- April
Late planting crop can be damaged by MYMV disease or by drought.
Crop Management
Fertilizer application Basal dressing : Apply and incorporate in to the soil before sowing.
Urea 35, Triple super phosphate 100, Murate of potash 75 kg/ha
Top dressing : Apply at flowering (about 30 days after sowing)
Urea 30 kg/ha

Weed control Keep the crop free of weeds in first 6 weeks from seedling emergence, until the
canopy is established. Before application of top dressing, weeding should be done. If there are more weeds regular weeding should be practiced in 2 weeks interval.
Irrigation Proper soil moisture is important for good and uniform germination (first 3 weeks). In dry condition, water supply should be done 4 days interval. After 3 weeks, irrigation should be done 7 days interval. At pod maturing time water supply should be cut down. Sufficient moisture is essential during germination, flowering and seed
Filling stages. Harvesting & Post-harvest Technology

Harvesting
Harvesting should be done when 90% of the pods turned black colour. Cut the plants using sickle and keep one day in the field to dry. Thresh using thresher or by tractor. Separate and clean the seeds and dry 1-2 days.