Teores de clorofila, produção e qualidade de frutos de morangueiro sob telas de sombreamento em ambiente protegido

Abstract

The strawberry production has been growing, consequently demanding new technologies to improve fruits productivity and quality. Among them, are the shading screens that help in the absortion of the radiation, interfering in the development and growth of the plant. The objective of the present work was to evaluate the contents of chlorophyll in the leaves, the productive development and fruits quality of two strawberry cultivars conduced under different shading screens, in protected ambient. The temperature was monitored during the growth period and the active radiation in two tipical days. The treatments were consisted of a double factorial with two cultivars (Camarosa and Oso Grande), four covers (at the presence of three shading screens and plus the witness) distributed in delineation of randomized complete blocks, with three repetitions with 20 plants per parcel. The data of the qualitative variables of the fruits were submitted to variance analysis and the differences between averages compared by the Tukey test at 5% significance. Regressions were used in the quantitative results. The results have shown that the cv. Camarosa presented greater concentrations of chlorophyll a; b and total, independent from the shading screen color and witness. There was greater production of chlorophyll b than a, in both cultivars when the presence and absence of screens. The cvs. Camarosa and Oso Grande had increment on the production from October, being increasing in until the end of December. It has been observed greater contents of sugar and total phenolics in the fruits of two cultivars produced in protected ambient when the absence and presence of shading screens in the month of November. But the contents of anthocynins are higher when harvested in October. When using shading screens inside the protected ambinet the cv. Camarosa produces more anthocynin in the fruits than in the cv. Oso Grande. Screens of blue, red and metallic colors, with shading meshes 40% (Cromatinet®) used inside the proteced ambient, do not alter the content of sugar, pH , diameter and color of the fruit