How to grow and care for Indian Hemp (Crotalaria Juncea)?

The Crotalaria juncea  plant, which also goes by a few other names such as brown hemp, Indian hemp, Madras hemp, or, more commonly, the sunn hemp, is a tropical South Asian plant belonging to the legume family. Generally considered to be native to India, it belongs to the Fabaceae family of plants. 

Generally, the Crotalaria juncea is a multipurpose tropical and sub-tropical, shrubby, herbaceous legume plant that grows to a height of 3-9 ft. It is an annual plant. It has a lengthy tap root with vigorous lateral roots and thick, ribbed, well-developed lateral roots that are clustered together. It bears vibrant, bright yellow flowers that bear a fruit commonly known as a ‘rattlepod’ because of its seeds that appear like they are clustered in a pod.

 

Source: Pinterest

Crotalaria juncea: Key facts

 

Phylum	Vascular plants
Class	Dicotyledons
Order	Legumes, milkworts, and allies
Family	Fabaceae
Genus	Longbeak Rattlebox
Species	Sunn hemp
Appearance	Tall, bright yellow flowers, thick, clustered stems with short, elliptical leaves spiralling  around it

See also: Common summer flowers in India  

The Genus

Crotalaria

Native Habitat

India

Sun Tolerance

High

Height

3–9 foot tall

 

Leaves

Trifoliate leaves, elliptical,

Leave Colour

Bright green

 

Cold Tolerance

Weak

 

Fruit

Light brown when mature, cylindrical, many seeded, hairy pod

Crotalaria juncea: How to grow?

The Sunn Hemp is a fast-growing species that is grown primarily during the rainy season. The seeds should preferably be sown in a well-prepared, fertilised, and weeded seedbed at a depth of 2-3cm. It is suggested you plant the seeds in rows but scattered farming works as well. Under favourable conditions, they germinate in around 3 days. 

The density of sowing seeds depends mainly on the location and the use intent of the crop. It is propagated by seeds under ideal conditions, said conditions being a moist and frost-free environment. When growing for fibre, the sunn hemp should be sown at a higher seed rate in order to produce erect stems, elongated roots, and high-quality fibre.

Source: Pinterest

 

Crotalaria Juncea: Maintenance

Crotalaria seems to grow on a number of soils, whichever you may find at your disposal, as long as it is well-drained. This plant does not like water logging. When grown for fibre, lightly textured soil with medium to high fertility should be used. 

When grown for other purposes, clayey and low-fertility soil can be used, too, given it is well-drained. A neutral range of pH is preferred, but if we’re talking numbers, a pH of 5-8.4 with an ample amount of phosphorus works. 

Crotalaria is a fast-growing plant that can suppress the growth of weeds through shading, thanks to its dense canopy. 

 

Crotalaria Juncea: Harvesting

There are a ton of different uses for the sunn hemp plant, and the method used for harvesting it particularly depends on the use case of the plant. 

If harvesting for fibre, the harvesting should be done at the flowering stage, 60-90 days after sowing, as the fibre is still thin enough to be harvested but not as thin as it would be in order to break. Harvesting by hand is preferred, but machine harvesting works as well. 

The top portion of the harvested plant is first cut off for cattle feeding. The main portion of the stem is then left to dry for around 1-6 days. 

When harvesting green manure, the Crotalaria plant should be ploughed within two months when the plants begin flowering. This is done so because, at this stage, the flower decomposes rapidly and will have a positive N balance at this stage.

 

Source: Pinterest

 

Crotalaria Juncea: Uses

While there are almost no existing medicinal benefits of the Crotalaria plant other than the fact that its seeds can help purify the blood and the skin. It has a plethora of commercial and botanical uses and benefits. 

The Sunn Hemp plant, like other hemp variants, is primarily grown as a fibre crop. It is mainly used for making fishing commodities like strings, ropes, twines, fishing nets, etc. 

For cattle, it is used for feeding and has been known to possess high amounts of protein for roughage. Raw seeds tend to be toxic and shouldn’t be fed without boiling. 

It is also used to make manure out of, and it does make for good quality manure because of its high nitrous amounts. It can also be used as an intercropping plant in cereal plants or for other cash crops as well.  

Source: Pinterest

 

Crotalaria Juncea: Toxicity

The seeds of the Crotalaria are known to be dangerously toxic and should not be fed to cattle raw.  

 

FAQs

What is the yield of the Crotalaria plant?

It has a pretty decent amount of yield given the type of soil and atmosphere it is grown in(18-27 t/ha).

What crops can the sunn hemp be intercropped with?

For agricultural purposes, it has been known to increase the growth and crop health of crops like wheat and soybean crops.

Are the materials harvested from the Crotalaria plant strong enough for fishing?

It has been found that the stems of the Sunn hemp have posed to consist of a tensile strength that is higher than that of steel as well.