ENDURCISSEMENT, RESISTANCE AU GEL ET CONTENU EN PROLINE LIBRE DE LA FLEOLE DES PRES (PHLEUM PRATENSE L.)

Abstract

After 4 wk of hardening at 1.5 ± 0.5 °C, the frost resistance (LT50) of three cultivars of timothy (Phleum pratense L) reached a maximum of −19 °C which slightly decreased thereafter. There was no significant difference in the frost resistance between the three cultivars, Climax, Clair and Bounty. The increase in proline of leaves, crowns and roots of timothy as well as the increase in the dry matter were highly correlated with the LT50. The correlation is of quadratic nature. In the discussion, the frost resistance of timothy is compared to that of alfalfa and winter wheat hardened in the same conditions and reported elsewhere.