Growth indicators for different pineapple cultivars compared with the current standard "Smooth Cayenne" in West Africa and Reunion Island: A first step toward modeling growth

European markets are segmented with several pineapple [Ananas comosus (L.) Merr.] cultivars, the 'Smooth Cayenne' (SC), the 'MD-2' hybrid, the new standard, 'Queen' and the 'Flhoran 41' (a red shell Cirad hybrid). Growth indicator standards are based on SC but growth characteristics may differ between cultivars. To determine if growth characteristics are comparable among pineapple cultivars, we analyzed the vegetative growths of SC, MD-2, Flhoran 41, and Queen Victoria in Ivory Coast and Reunion Island. First, the vegetative growths of plants produced from stem suckers were monitored using three indicators, the number of leaves, the D leaf weight and the plant weight. Then, the growths of plants produced from different types of planting material of Flhoran 41 were compared. Finally, the seasonal variations of Queen Victoria growth were analyzed to establish the basis of a heat unit model of growth for pineapple. All cultivars showed similar growth patterns but with some specificities. Plant weight increases were higher for MD-2 and Flhoran 41. At forcing, the D leaf weight was significantly lower in Flhoran 41 but the plants had a greater number of leaves resulting in similar plant weights. As already observed in SC, Flhoran 41 stem suckers grew faster than slips and crowns. Finally, the plant weight increase in Queen Victoria was highly correlated with the sum of temperatures. These observations allowed us to establish the basis of a heat unit model of pineapple growth based on sum of temperatures. (Résumé d'auteur