GA3 induz partenocarpia e aumento do tamanho dos frutos em atemoieira 'Gefner'

Abstract

The objective of this work was to evaluate the effect of gibberellic acid (G*A_{3}) and artificial pollination by means of pollen of sugar apple on establishment, yield and quality of atemoya 'Gefner' fruit under irrigated conditions. The experiment was carried out in a commercial orchard of atemoya 'Gefner' in Janaúba, Minas Gerais. The experimental design was at random with eleven treatments, four replications and five plants per parcel. The treatments were: 1 = artificial pollination with pollen of sugar apple (APPSA) (control), 2 = APPSA + 500 ppm G*A_{3} applied on the 1st week after anthesis (WAA), 3 APPSA + 500 ppm G*A_{3} applied on the 1st and 3rd WAA, 4 APPSA + 500 ppm G*A_{3} applied on the 1st, 3rd and 5th WAA, 5 APPSA +1000 ppm G*A_{3} applied on the Ist WAA, 6 APPSA +1000 ppm G*A_{3} applied on the 1st and 3rd WAA, 7 = APPSA +1000 ppm G*A_{3} applied on the 1st, 3rd and 5th WAA, 8 = 1000 ppm G*A_{3} applied at flowering, on thelst and 3rd WAA, 9 = 1000 ppm G*A_{3} applied at flowering, on thelst, 3rd and 5th WAA, 10 1500 ppm G*A_{3} applied at flowering, Ist and 3rd WAA and 11 1500 ppm G*A_{3} applied at flowering, 1st, 3rd and 5th WAA. Pro-Gibb commercial product, consisting of 10% of gibberellic acid, was used. Fruit set, length and diameter and the physical and chemical characteristics of fruits were evaluated. The results were submitted to analysis of variance and means were compared by the Scott-Knott test at 5% probability. The percentage of fruit set does not differ among the different treatments, showing an average of 77% fruit set until harvest. Three applications of 500 ppm G*A_{3} after artificial pollination of atemoya 'Gefner' provide larger fruits. Four applications of 1500 ppm G*A_{1} without artificial pollination, results in the production of seedless fruit with the same quality of pollinated fruits, but with less firmness.