Frutificação efetiva e produção de macieiras CV. Gala tratadas com extrato de alga Ascophyllum nodosum e thidiazuron

Abstract

To meet the growing demand for apple consumption, it is necessary to search for technologies that improve the productive aspects. Thidiazuron is a phenylurea with cytokinin action that can promote the increase in fruit set and fruit size. The application of biostimulants derived from algae extracts may be an alternative for the organic management of apples. The objective of this study was to evaluate the fruit set and production of apple cv. 'Gala' treated with extract of seaweed Ascophyllum nodosum and thidiazuron. The experiment was arranged during the 2015/2016 and 2016/2017 cycles in the city of Porto Amazonas – PR, in apple trees of the 'Gala' cultivar on the 'Marubakaido' rootstock with EM-9 intergraft. The experimental design was a randomized block design, with 8 treatments and 5 replications, with experimental plot consisting of 1 plant. The treatments were: thidiazuron at concentrations of 10 and 15mg / L, Ascophyllum nodosum seaweed extract at concentrations of 0.1; 0.2; 0.3; 0.4 and 0.6% and one untreated check, and in both cycles the applications were carried out in the full bloom stage (F2). The average fruit weight (g), number of seeds per fruit, length and mean diameter of fruit and length/diameter ratio (C/D) of fruits, titratable acidity, soluble solids, pulp firmness (N) and growth of branches (cm). Both thidiazuron and algae extract, even at low concentrations, influenced production, with distinct effects for each evaluation cycle. In general, the extract of Ascophyllum nodosum at 0.3 and 0.4% promoted higher number of fruits per plant, higher productivity per plant, and growth of branches in at least one of the experiment cycles, with similar results to the use of the traditional thidiazuron-based product.