Características fitotécnicas e agrometeorológicas do mirtileiro submetidos a diferentes épocas de poda, na região de clima temperado

Abstract

The blueberry tree (Vaccinium sp.) is a promising fruit tree for the southern region of Brazil, making it necessary to carry out studies aimed at the behavior of the species in regional climatic conditions and the improvement of the production system for consolidation in the world market. Therefore, the objective was to determine the use of incident solar radiation and its influences on phenological development, productivity, fruit quality and physiological processes in blueberry crops subjected to different pruning times. The experiment was carried out in a commercial orchard, in the municipality of Pelotas - RS, during the agricultural years 2021/2022 and 2022/2023. The experimental design was in randomized blocks, in a 2 x 3 factorial scheme, summer pruning (with summer pruning x without summer pruning), winter pruning season (early x conventional x late) with four replications, with one plant per repetition. The work was carried out in three stages. In the first study, the variables analyzed were: radiation balance, incident global solar radiation, reflected solar radiation, albedo, shortwave balance and longwave balance. In the second study, phenological assessments were carried out once a week, according to the description of the bud development stages. In the third study, when the fruits reached the stage of complete maturation, physical-chemical evaluations were carried out, namely: soluble solids content, pH, titratable acidity, number of fruits per plant, average fruit weight, diameter, length, production per plant, productivity and color. Thus, it was concluded that: a) The albedo of blueberry ‘Delite’ with interrows completely covered by spontaneous vegetation, the albedo is 0.27 and 58% of the daily global solar radiation is made available to the environment as radiation balance; b) The phenology of blueberry ‘Delite’ was not influenced by summer pruning, being dispensable under the conditions under which the experiment was carried out. The different winter pruning times changed the crop cycle and the thermal need, however, there was no interference in the harvest time, showing that the producer has a longer period to carry out pruning; c) ‘Delite’ blueberry plants not pruned in the summer and pruned between the months of June and August in the winter, showed greater fruit production and quality.