Yield
Forage yields are variable, from 5.8 t/ha DM in Ethiopia, to much less than 2.5 t/ha DM in Australia (Tarekegn et al., 2015; Siddique et al., 1996). In Portugal, associations of purple vetch with rye or with cereals mixtures (oats and triticale, triticale and rye) yielded over 8 t/ha DM (Carnide et al., 2002).
Management
Vicia benghalensis establishes rather slowly and requires a well-weeded seedbed prior to sowing. It should be sown at 3-5 cm depth and can be either drilled or broadcast. In dry places, irrigation prior to seeding can be useful (UC SAREP, 2006). In early growth stages, purple vetch is a very poor competitor for weeds. It should be sown in autumn for winter grazing (in March, in Australia) (DAF, 2011). Purple vetch can be sown in association with cereals such as oats, or with grasses such as annual ryegrass (Matic et al., 2008). In the subtropics, it is possible to grow it with summer growing grasses (Matic et al., 2008). In Portugal, it was shown that purple vetch could be profitably sown in association with a mixture of oats and triticale, or with a mixture of triticale and rye (Carnide et al., 2002).
Purple vetch regenerates poorly and should not be chosen for the establishment of permanent pastures (DAF, 2011). However, it has a rather high percentage of hardseededness which can make it a weed in the next crop (Matic et al., 2008). Purple vetch can be grazed though it is less resistant to close grazing than other vetches. It should be grazed or cut once it has reached 10 nodes (over 40 cm in height) and before pods forming (as the seeds are toxic).
Purple vetch can be cut for hay or silage and harvested with a cereal harvester. The best nutritive value of hay and silage is obtained for purple vetches cut just before flowering, but a good trade-off is to cut at flowering to increase forage yield while preventing the toxic effect of the seeds (Matic et al., 2008).
