sucrose content is one of the main factors sugarcane (Saccharum spp.hydrids)breeders use in selecting new cultivars.To determine how growth and sugar content have been altered by six cycles of recurrent selection for sucrose, five cultivars from the first generation (released from 1924 to 1933)were compared with five cultivars from the seventh generation (released from 2003 to 2007).In July of 2006 and 2007,we flagged 20 stalks per plot and marked the top internode that was just beginning to elongate.We then sampled one stalk per plot at weekly to biweekly intervars for 12 weeks.We measured stalk length and internode number,and the length ,fresh weigth,dry weigth,water content,and sugar content of the marked internode.Stalks from the Generation 7 cultivars were taller,and had more internodes than those from Generation 1 cultivals.The marked internodes of Generation 7 and Generation 1 cultivars had similar elongation rates during early development,but elongation ended earlier in Generation 7 cultivars so that internodes of Generation 7 cultivars wre shorter when fully elongated than those of Generation 1 cultivars.These shorter internodes had lower fresh weigths,but similar dry weigths as the longer Generation 1 internodes.Water content alsodecreased faster in Generation 7 than Generation 1 internodes.Generation 7 internodes had more total sugar and more sucrose througout development.Generation 7 internodes also maintained a higher sucrose:total sugar radio until the end of the sampling period.We conclude that recurrent selaction for sucrose content in sugarcane has altered the allocation of photosynthate from growth to storage wihtin the internode.This is possibly due to a change in the regulation of sucrose metsbolism wihtin the internode.