Produção extemporânea de cultivares de amoreira-preta em região subtropical

Abstract

The cultivation of blackberry (Rubus spp.) in non-traditional regions has been gradually expanded through the use of different techniques in cultural management, with emphasis on pruning. Off-season production is desired because of the smaller amount of fruit offered in the off-season, which has the advantage of greater profitability. However, there is no definition of how to displace blackberry production from the normal harvest season in subtropical regions, which are concentrated between the months of October and January, in Brazil. The aimed of this study was to evaluate the production and scaling of blackberry cultivars Tupy and Brazos in a subtropical region, with four management pruning. The experiment was carried out in a location with Cwa climate, 910 m height, at 21°14” S, 45°00” W. The treatments consisted of four pruning times, one conventional (drastic pruning in January and reduction of pruning productive stems in July) and three drastic pruning managements carried out in the first fortnights of January, March and May, with application of 10% urea and hydrogen cyanamide at a concentration of 3%, five months after drastic pruning. The experimental design was in randomized blocks, in a 2 x 4 factorial scheme (two cultivars and four pruning managements), with four blocks. The vegetative and reproductive phenology, production and physicochemical quality of the fruits were evaluated. The growth curve showed a variation in the length of the main stem from 73 to 163.33 cm in 12 weeks, with the drastic pruning carried out in May being more affected. The drastic pruning seasons in January started production in August and the rest after October, where the length of the production cycle in the drastic pruning seasons in January, March and May was 50 to 58 days, while the period of conventional pruning had the longest duration with 106 days, the latter having started in November. The cv. Brazos had higher fruit production and 'Tupy' had better fruit quality, both in the drastic pruning in January.