Plant · P-243

Rice Bean

Vigna umbellata

Rice bean is the one bean in this group with a day-length problem rather than a heat problem: it needs roughly a twelve-hour day to flower, so a spring or early-summer sowing at this latitude keeps it in leafy growth until autumn and then leaves too few frost-free days to fill seed. The practical fix is to grow it for what the long vegetative run already gives - forage and green manure - rather than count on a dry-seed harvest from ordinary seed; a short-season variety can still deliver seed if that is the goal. It shrugs off both drought and waterlogging equally well, which is unusual among beans, and its forage feeds cattle, buffalo, goats and sheep, who need only a few days to get used to the taste. As a green manure it beats other legumes at lifting the yield of the crop planted after it, the strongest claim of any bean in this group.