Reguladores vegetais e atividade de invertases em cana de açúcar no início da safra

Invertases play an essential role in partitioning photosynthates between storage and growth. The objective of this study was to evaluate the activity of acid and neutral invertases and the role they play in controlling the accumulation of sucrose in sugarcane as a result of the application of plant regulators in the beginning of the cropping season. A randomized block experimental design was adopted, with five replicates. The treatments consisted in the application of three plant regulators of the class of growth inhibitors (Sulfomethuron-methyl -20g ha-1, Glyphosate -0.4L ha-1, and Compounds from organic carboxylic radicals + Glyphosate -1L ha-1 + 0.15L ha-1), in addition to a control (natural ripening). The acid and neutral invertase levels are affected in different ways and intensities, due to the active principle used as ripening agent and to the weather conditions.In sugarcane variety RB85-5453, with the conditions described in this experiment, it is suggested high levels of soluble acid invertase in relation to levels of neutral invertase; however, the first was characterized by high sucrose content in the stalks.Inverse correlation could be established for sugarcane variety RB85-5453 between soluble acid invertase levels and effective sucrose accumulation in the stalks.