Título en español.

The time-course for induction of growth, sucrose, and enzyme changes by Polaris (N,N-bis [phosphonomethyl] glycine), a commercial sugarcane ripener marketed by Monsanto Agricultural Products Company, was studied with early-juvenile sugarcane propagated by sand culture. The ripener was administered as an aqueous foliar spray containing 3000 p/m active ingredient. Plant samples were harvested just prior to treatment and from 8 h to 10 days thereafter. Acid invertase was significantly repressed within 24 hand sucrose increased in both leaf and expanding stem tissue within 48 h. The enzymes trehalase and ATP-ase declined in expanding stem tissue by the fourth and tenth day, respectively. Soluble protein was significantly repressed from the seventh day onward. Significant growth repression was first recorded at 7 days. The time-course of Polaris action is discussed in the context of spatially- and biochemically-discrete tasks to be performed within an early-juvenile model.