Abstract

SALGADO, Sergio et al. Manejo de la fertilización en el rendimiento, calidad del jugo y actividad de invertasas en caña de azúcar. INCI [online]. 2003, vol.28, n.10, pp.576-580. ISSN 0378-1844.

Excess N in plant tissues during harvest is the main cause of low sucrose content in sugarcane (Saccharum officinarum L.) juice. N content is the product of a balance between the amount of sucrose synthesized and the amount hydrolyzed by acid and neutral invertases. The object of this work was to determine the relationship between sugarcane juice quality (ºbrix, purity and concentrations of sucrose and reducing sugars) and the activity of acid and neutral invertases in plants submitted to different fertilization managements. The experiment was carried out in sugar cane crops established with cv. Méx 69-290 (ratoon) in a Vertisol and cv. Méx 68-P-23 (ratoon 3) in an Inceptisol, in Tabasco, Mexico. Treatments were combinations of 160 or 200 kg·ha^-1 N, plus 67 or 202 kg·ha^-1 K applied either superficially or buried, one or three months after plant regrowth. All treatments received 35kg·ha^-1 P, except the control treatment without fertilization. Treatments were arranged in a randomized block design with four replications. Sugarcane was harvested at an age of 10.5 and 11.5 months in the Vertisol and Inceptisol, respectively. Treatment 160-35-67 N-P-K (kg·ha^-1) applied as a mixture of ammonium sulphate, triple superphosfate and KCl, buried three months after regrowth, produced higher yields than those of the control in both soils (130.7 and 113.6 ton·ha^-1). Sugarcane juice quality was not affected by the fertilizer rates tested, nor the activity invertases modified by the different management practices.

Keywords : Invertasa Ácida ; Invertasa Neutra; Fósforo ; Nitrógeno ; Potasio ; Saccharum officinarum L.