Ethephon no raleio químico de frutos de pessegueiro cultivar Chimarrita

Abstract

The thinning is one of the main cultural practices of the peach tree, which can be done manually or chemically. This study aimed to evaluate the effect of ethephon as chemical thinnig of peach fruits of the Chimarrita cultivar. The experiment consisted in the application of ethephon at doses of 0, 50, 80, 110 and 140 mg L^-1, by spraying to the drip point, and a manual thinning treatment, all performed on 09/10/2015, in commercial orchard located in Veranópolis-RS. The experimental design was completely randomized design with six replicates and one plant per plot. The evaluations occurred in six branches demarcated per plant in a total of 36 branches per treatment. The following parameters were assessed: percentage of flruits thinned, fruiting index, fruit mass, diameter and length, pulp firmness, soluble solids (SS) and titratable acidity (TA). The concentration of ethephon of 80 mg L^-1 presented rates ​​of fruiting index (21.2%) and fruit thinned (72.1%) close to the treatment manual thinning (management taken as reference), with values obtained of 22.4% and 75.2%, respectively. The physico-chemical characteristics did not differ between the treatment of ethephon 80 mg L^-1 and the manual thinning, with fruit mass and SS of 104.9g and 8.0°Brix for the dose of 80 mg L^-1 and 113.1g and 8.1°Brix, for the manual thinning. The application of ethephon in the dosage of 80 mg L^-1 is efficient for the thinning of peach fruit cv. Chimarrita.