SUGARS AND AUXIN QUANTIFICATION IN THE INITIAL DEVELOPMENT OF SUGARCANE MINI-STALKS

Abstract

Reserve carbohydrate and the plant hormone auxin present in the stalk are involved in the development of sugarcane plant. Thus, this study aimed to quantify sugars and auxin content in the initial development of stalks and sugarcane buds, as a function of diameter and position in the stalk. The experiment was conducted in a 3x3 factorial scheme (diameter x stalk section), with four replicates. Eleven-month-old plants stalks were classified into three diameters (fine < 2 cm; medium 2-3 cm; thick > 3 cm) and divided into three sections (apex, middle and base). Data were submitted to analysis of variance, and when significant the means were compared by the Tukey test at 5% probability. The diameter factor resulted in greater interference in the content of the biochemical variables evaluated (sugars and auxin), in comparation to stalk section. Biometric variables (length and dry mass of shoot and roots, budding and budding speed index), in general, were mostly affected by stalk section factor. The diameter factor interfered in the content of endogenous auxin in the stalk and buds. Root growth was related to endogenous auxin concentration and the highest sprouting percentage was obtained from the apical section of the talk due to the availability of reducing sugars content. The use of mini-stalks for the propagation of sugarcane proved feasible.