Abstract

The application of CPPU increases fruit size and weight in blueberries, but the impact of CPPU on postharvest life of blueberry fruits has not been studied. A greater fruit size could reduce wax deposits on the fruit and diminish postharvest life. In this research the effect of CPPU on the quality and postharvest life of highbush blueberry fruit was assessed in the context of 30 and 45 d of sea transport, plus a shelf life of 1 and 5 d. The study was done in a five-year-old commercial 'Duke' blueberry field, located in Linares (35 degrees 57 '' 56' South; 71 degrees 40 '' 73' West). The treatments were: 10 or 5 ppm of CPPU applied 10 and 17 d after full bloom (DAF) plus a control (not sprayed). Evaluations were done at harvest, after 30 d cold storage (1 degrees C) + 1 d at room temperature (30+1), as well as 30+5, 45+1 and 45+5; they included quality assessments (soluble solids, firmness, color and bloom) and condition (% rotten fruit). A completely randomized design with 4 replications was used. The application of 10 ppm CPPU reduced both fruit coloration and soluble solids (<1.5%) at harvest. No differences among treatments were found for fruit firmness at harvest. The most relevant effect was due to highest CPPU rate (10 ppm), since it increased berry weight (24.2%) and bloom (59% in bloom index) at harvest. The application of CPPU significantly reduced fruit rotting (15% at 45+5 evaluation). Fruits treated with CPPU had reduced firmness loss (<30.5% at 30+1) and higher soluble solids (levels above 12 degrees Brix) during storage. Color during the storage evolved to maximum levels in all treatments (all treatments over the 98% in 45+5 days). A regression between quality indices vs. fruit condition had a high level of significance (r>0.85) for the soluble solids content and bloom (wax on the fruit). No consistent correlations were found for firmness.