Phytoregulators in the Reproductive and Productive Characteristics of Plants and Physicochemical Characteristics of ‘Packham’s Triumph’ European Pears

Abstract

The objective of this study was to evaluate the reproductive, productive and physicochemical characteristics of fruits (fruit volume and soluble solids) of ‘Packham’s Triumph’ pear trees treated with different doses of phytoregulators. The experiment was carried out in the 2014/2015 and 2015/2016 cycles, using 1-naphthaleneacetic acid (NAA), 2-chloroethyl phosphonic acid (Etefon) and 6-Benzyladenine (BA) phytoregulators, each at doses of 200 and 300 ml L-1. The experimental design consisted of a randomized block with five replicates, where each experimental unit consisted of one plant. Significance was only found for soluble solids in the 2014/2015 harvest, observing that the highest mean was identified in plants treated with 300 ml L-1 Etefon, (15 °Brix), while the lowest soluble solids content was observed with the dose of 200 mg L-1 of NAA, (11 °Brix); in the 2015/2016 crop, the highest number of inflorescences of the year was identified in plants treated with 200 ml L-1 of Etefon, (1.66) and the lowest value for the treatment with 300 ml L-1 of BA, (0.17). Effective fruiting in the value of 58.33% was also observed and verified for the plants treated with 300 mg L-1 of NAA, differing from all except from 200 ml L-1 BA. Only the plant growth regulator, NAA, at the dose of 200 mg L-1 provides low content of soluble solids in the fruits and Etefon 300 mg L-1 provides high content of solids solubles. The lowest number of branch inflorescences of the year was in plants treated with 6-Benzyladenine at a dose of 300 ml L-1 and the highest at a dose of Etefon 200 mg L-1. The NAA dose of 300 mg L-1 and 6-Benzyladenine dose of 200 ml L-1 had greater effective fruiting, but not did not reflect on the production per plant and productive efficiency. There was no benefit observed in the return bloom with the application of phytoregulators. Besides, no benefits were observed in the return bloom with the application of phytoregulators.