Impact of Shorter Picking Intervals on the Storability and Postharvest Quality of Rabbiteye Blueberries cv. 'Brightwell'
Description
Research Hypothesis, Findings, and Data Interpretation We hypothesized that shorter harvest intervals would improve the postharvest quality and storability of rabbiteye blueberries (Vaccinium virgatum cv. ‘Brightwell’). Specifically, frequent harvesting (every 2–3 days) was expected to reduce berry damage, weight loss, and firmness deterioration while maintaining optimal sugar and acid content. In contrast, longer harvest intervals (seven days) were anticipated to lead to greater fruit deterioration due to prolonged field exposure. To test this, blueberries were harvested at 2-day (Trt A), 3-day (Trt B), and 7-day (Trt C) intervals during the 2023 and 2024 seasons in Georgia, USA. After harvest, fruit was stored at 1°C and 85% relative humidity for 21 days, with quality assessments at 0, 7, 14, and 21 days. Parameters measured included berry damage (%), berry diameter (mm), weight loss (%), firmness (g/mm), total soluble solids (°Brix), titratable acidity (% citric acid), and anthocyanin concentration (mg cyanidin-3-glucoside/g FW). Key Findings Berry Damage and Weight Loss: The 7-day harvest interval (Trt C) resulted in significantly higher berry damage and weight loss compared to 2-day and 3-day intervals. Berries from shorter harvest intervals maintained a better overall appearance. Firmness Retention: The 7-day interval led to the most significant firmness decline during storage. The 2-day and 3-day intervals better preserved fruit texture. Total Soluble Solids and Titratable Acidity: Sugar content remained stable across treatments. Acidity levels declined more in the 7-day interval, likely due to extended field exposure. Anthocyanin Concentration: The 7-day interval berries had the highest anthocyanin content, suggesting extended ripening increased pigment accumulation. However, this came at the expense of storability and texture. Data Interpretation and Practical Implications Optimal Harvest Interval: A 3-day harvest interval (Trt B) provided the best balance between minimizing postharvest losses and maintaining quality, making it a practical option for growers. Postharvest Storage Considerations: Longer harvest intervals resulted in higher deterioration, requiring additional interventions (e.g., rapid cooling, packaging) to mitigate losses. Anthocyanin Trade-off: While extended field exposure increased anthocyanin levels, it negatively impacted firmness and storability, suggesting that quality cannot be defined by pigment accumulation alone. Conclusion Our findings confirm that shorter harvest intervals significantly improve postharvest blueberry quality. A 3-day interval is recommended to optimize fruit storability while maintaining efficient harvesting operations. These insights provide valuable guidance for blueberry growers in warm climates seeking to extend marketability and reduce postharvest losses.