Chrondus crispus was grown vegetatively in seawater in outdoor tanks at four different locations in the Maritimes. The growth rate and production of carrageenan by strain T4 (a carposporic plant) was superior to that obtained from wild plants (a mixture of carposporic and tetrasporic plants) obtained from the area adjacent to the trials. The results obtained at the two locations in Nova Scotia were similar. The slightly higher yields of plants in Ellerslie, P.E.I. could be attributed to the more favorable growth conditions, including nutrients and temperature. More carrageenan was produced per tank by the unfertilized plants than by the fertilized plants.On a cultiv\ue9 du Chondrus crispus de facon v\ue9g\ue9tative dans des basins d'eau de mer, \ue0 quatre endoits diff\ue9rents dans les Maritimes. La souche T4 (algue \ue0 carpospores) avait un taux de croissance plus \ue9lev\ue9 et produisait plus de carragah\ue9nine que les esp\ue8ces sauvages (m\ue9lange d'algues \ue0 carpospores et t\ue9traspores) croissant dans la r\ue9gion adjacente \ue0 celle des essais. Les r\ue9sultats provenant des deux r\ue9gions situ\ue9es en Nouvelle-Ecosse \ue9taient semblables. Des conditions de croissance plus favorable (richesse en nutriments, temp\ue9rature et salinit\ue9 plus propices), peuvent expliquer les productions l\ue9g\ue8rement plus \ue9lev\ue9es des esp\ue8ces cultiv\ue9es \ue0 Ellerslie (I.-P.-\uc9.). Les algues non f\ue9cond\ue9es ont produit par bassin plus de carragah\ue9nine que les algues f\ue9cond\ue9es.NRC publication: Ye