Monda mecânica de flores em pessegueiro com o equipamento Saflowers® Electric na cv. 'Very Good': avaliação do impacto na produção e qualidade dos frutos

Abstract

Usually the peach tree has a high number of flowers per branch and, after blossom, a high number of fruit that requires fruit thinning. The manual thinning is the most common practice. This practice is time consuming and represents high labour costs. The aims of flowers or fruit thinning is to improve fruit quality and increase the fruit size, and simultaneously, to promote the best balance of plants for regular production across life cycle. There exists in the market diverse equipment for the accomplishment of flowers thinning, so this study was designed with the objective of evaluating the impact of mechanical flowers thinning using the Saflowers® Electric equipment. In two commercial orchard of 'Very Good' cultivar situated north and south of the Gardunha Mountain, in the Beira Interior region, two treatments - a flower thinning and a control – no thinning were applied. Yield and fruit quality were evaluated.  The intensity of flower thinning (number of removed flower per number of initial flowers) was similar in both orchards, and initial fruit set (number of fruits per number of flowers) was 52% and 87%, respectively. In both orchards thinning was performed at stages F and G, and in the case of the orchard located in the south, Hand thinning was done at 117 DAFB. The average of total production was similar in both orchards, between 26 and 28 t/ha, but the total production was always lower in the thinning treatment. The flower thinning had a positive effect in reducing no commercial fruits for both orchards, and there was an increase of fruits of the size class ≥ A at orchard located in the north of Gardunha Mountain (94%) but this positive effect on increase fruit size was not observed at the orchard located at south of the Gardunha Mountain, where the fruit set rate was higher. The flowers thinning treatment showed a lower fruit firmness at harvest (P<0.05) which indicates an early ripening. An increased IR Although only statistically significant (P <0.05) were found for the orchard located in the north the SSC was higher for flowers thinning treated trees in both orchards, showing a mean difference of 2º Brix between treatments. A tendency for higher IR was observed in both orchards for thinning treatment, reaching an average difference of 2ºBrix between treatments.