Not often enough does Federico Garcia Lorca's potent blend of heightened poetry and rural realism successfully bridge the language gap from Spanish to English.

Frank McGuinness here supplies a suitably earthy version of the best-known work by the Spaniard, the 70th anniversary of whose death is being commemorated in an ambitious two-month season. Yet these fine words are let down by a jerky production that at times resembles a world music festival run out of control.

"I'm a country woman with no child and I'm useless" is Yerma's succinct summation of her predicament. Married to uninspiring farmer Juan for nine years at the action's start, she can see evidence of nature's fecundity everywhere but in her own belly. Yerma finds herself caught in the classic bind of a shame culture: the more she talks with sympathetic neighbours, the more the village as a whole starts to gossip.

As Yerma, Kathryn Hunter exhaustingly underscores every line of Lorca's lovely lyricism with a different gesture. Such a flittery, jittery performance does nothing to illuminate Yerma's thwarted maternal longings and increasing, disastrous mental fragility. The rest of the cast largely look the wrong age for the characters they are portraying.

Director Helena Kaut-Howson seizes upon the elements of pagan ritual and plays them up wildly, with live musical accompaniment and a graphic fertility ceremony. This visceral approach works beautifully, however, for the scene with the washerwomen.

Immaculately choreographed, they slap their wet clothes down like whips, as if to punish a patriarchal society that aims to keep its women rearing infants behind closed, preferably locked, doors.