Variation in HCN potential among cultivars of white clover (Trifolium repens)

The hydrogen cyanide potential (HCNp) of 17 cultivars of white clover were compared. With inadequate phosphorus supply, HCNp ranged from 24 mg kg DM −1 for cv Lucky to approximately 640 mg kg DM −1 for cv Huia and from 6 to 322 mg kg DM −1 for the same cultivars, with adequate phosphorus. The four North American cultivars examined had notably lower HCNp than all European or Australasian cultivars except cv Clarence.