A tall-growing summer annual legume, sunn hemp tolerates hot, dry conditions well. Use as a green manure/cover crop to provide both organic matter and fix nitrogen during the period between summer and winter cash crop. Sunn hemp produces signifi-cant biomass in 6-7 weeks.
Sunn hemp was originally used as a fiber crop in India and has a high lignin content. Sunn hemp can be grazed
After 25 to 35 DAP (Days After Planting) the stems become lig-nified. The leaves are very palat-able and nutritious but the stems are not.
In good growing conditions, the plants can reach a height of 6 feet with a stem diameter of up to 1 -2 inches. It has a long tap root with many lateral branches.
Sunn hemp works well in summer mixes to add varying heights to the cover, but keep the seeding rate low in a mix, as it is competi-tive. It performs better on soils that are sandy or well-drained.
It should only be grown if it can be easily terminated with available equipment. Best mowed with flail mower or chopper and left as residue or incorporated as a green manure.
Using Sunn Hemp for management of Plant Parasitic Nematodes
Sunn hemp can be used as a rotational break crop for suppressing plant parasitic nematode populations in both vegetable and field cropping systems. Sunn hemp uses different modes of action to suppress plant parasitic nematodes, making it an efficient cover crop for nematode management. It is not only a poor host/”non-host” to many plant-parasitic nematodes, but it has been shown to produce toxic compounds that work against several key nematode pests.
Sunn hemp also can enhance natural enemies of plant-parasitic nematodes, such as fungi that trap nematodes or feed on their eggs.
Inoculate with King Fisher BioTrigger Cover Crop or N-Dure Peanut Inoculant (Bradyhizobium spp)