Introduction:

Sunnhemp (Crotalaria juncea L.) is a crop grown for the fibre yields Sunnhemp seed is source of seed protein used for manufacturing adhesives. It is also a green-manuring crop, but a minor fodder crop of minor importance. It is the most suitable indigenous raw material for manufacturing tissue paper and paper for currency. In rural areas, it is used for making ropes, twines and nets. The crop is grown in almost all parts of India the states of Uttar Pradesh and Madhya Pradesh are most prominent in this respect.

Climate and soils:

The crop grows best in tropical and subtropical climate. It is grown in kharif in the northern states. In the southern regions, where climate is, more or less, equable and the winter is not pronounced, it is raised in rabi also. A minimum of 40cm of rainfall distributed in not less than 50 rainy days during the growing season is a primary requisite.
It requires a rich, well drained soil with plentiful organic matter. The soil should be well drained and at least three feet deep. It also goes on well drained clay soils, irrigated medium black soil and light coastal soils. Salinity above 0.05% is injurious and the calcareous soils are too poor for banana.Well-drained alluvial soils, having a sandy loam or loamy texture are suitable. For uncultivated fallows or freshly reclaimed soils is an ideal. Alluvial soils with low pH are not suitable, unless acidity has been corrected by liming.

Varieties::

Land Properties

After the application of the fertilizer during the preparation of the land, sowing follows immediately. After sowing, the soil is raked and laddered in order to put the seed 2-3 cm below the surface.

Sowing

The sunhemp crop sown in the kharif. It is sown by broadcasting and in rows. In broadcast sowing, the seed rate is about 25kg per hectare; in lines (30cm) line to line spacing and 5-7cm plant to plant spacing, the seed requirement is only 15 kg per ha.

Fertilizer:

Since it is a crop that fixes its won nitrogen, generally no nitrogen fertilizer are added. Doses of phosphorous and Potash about to 20kg per ha are beneficial.

Interculture:

Weeding is not necessary. A common weed associated with sunnhemp is Ipomoea sp. unless manually weeded out, they hamper the growth of the crop. Seeds of these weeds can be separated from sunnhemp seeds with some care.

Plant protection:

Pests

Hairy caterpillars
Caterpillars are gregarious and cause a serious defoliation of the plants
Controls
Egg masses are prominent; they may be collected and destroyed ; dust 5-10% Heptachlor

Stem or shoot borers
Caterpillars cause small gall like swelling on shoots and stems
Control
Spray 0.03% Diazinen or Monocroptophos

Capsid bug,
Nymphs and adults congregate in large number and suck the sap from the leaves
Control
Dust 5% Heptachlor

Disease

Powdery mildew
White powdery patches appear on the undersurface of the leaves; the corresponding upper portions just above patches become pale and brown
Control
Dust the crop with finely powdered sulphur @ 15 kg per hectare. 

Wilt
Leaves turn prematurely yellow and wither; the vascular tissues of the root and stem are discoloured black; the affected plant dries up
Control
Grow resistant varieties; practise crop rotation and crop sanitation

Harvesting and Storage:

The fibre crop gets ready for harvest in 120-150 days. Pod formation is considered the proper stage of harvesting. Early maturing strain is generally harvested at the dead ripe pod stage in order to yield both fibre and seed. In this case the total cropping period is 80 days. The plants are harvested with sickles and the bundles are kept in the field for 2-3 days for the leaves to be shed.