Efeitos fisiológicos e bioquímicos da mangueira ‘Ubá’ em resposta ao manejo de desponte e aplicação de paclobutrazol

Abstract

The „Ubá‟ mango tree cultivar has an irregular flowering, which which limits production during the year. With the increasing demand for 'Ubá' mango by the pulp and juice processing industry in the north of the ES, it has become essential to seek technologies that improve the production of this crop. The objective of this work was to analyze the physiological and biochemical effects of the pruning of the branches and doses of paclobutrazol in the floral induction of the „Ubá‟ mango tree, located in the commercial orchard in Colatina-ES during two plating seasons. The data were analyzed in a randomized block design with four replicates, in factorial arrangement (2x5+1), five doses of paclobutrazol (0; 0,5; 1,0; 1,5 and 2,0 linear g.m-1 of the crown) and two branches management (with or without pruning) and an additional treatment (control) whose plants do not undergo pruning, pruning of the branches and application of paclobutrazol. The chlorophyll a fluorescence was the technique used to evaluate the photochemical efficiency, the carbohydrate and chloroplastidic pigment contents and the productivity were also determined. The results indicated that plants with pruning of the branches at the 2.0 and 1.0 gm-1 linear doses of the paclobutrazol for 2016 and 2017, respectively, improved the photosynthetic performance of photosystem II (PIABS), increased electron transport moves further than quinone A (ψE0) and the electron transport flux (ET0/CS0). The contents of total soluble sugars and reducing sugars of the leaves increased with the increment of the doses of paclobutrazol; however the levels of chloroplastídicos pigments reduced with the increase of the doses of the phytorregulator. There was a positive relationship between productivity and PIABS. The application of paclobutrazol combined with the pruning of branches positively affected the photochemical efficiency of 'Ubá' mango leaves reflecting better productivity.