Rooted cuttings of grape vine, cvs. __ampersandsignlsquo;Black Grenache__ampersandsignrsquo;, __ampersandsignlsquo;Carignane__ampersandsignrsquo; and __ampersandsignlsquo;Alicante Bouschet__ampersandsignrsquo;, kept at 25 __ampersandsignplusmn; 2__ampersandsigndeg; C in the dark, I transferred it 30-days after budburst to a greenhouse at 25__ampersandsigndeg;C (day), 20__ampersandsigndeg;C (night) and 12 hr light. A week after, foliar growth started and normal green pigmentation appeared. 21 days later, the synthesis of anthocyanins appeared in the leaves and stems. After 28 days, calcium content, expressed as the percentage of dry matter in the shoot apex, decreased and symptoms of calcium deficiency appeared. A hypothesis was proposed to explain the mechanism inducing calcium deficiency by the pretreatment to darkness.