Pearl netting affects postharvest fruit quality in 'Vergasa' sweet pepper via light environment manipulation

Red sweet pepper (Capsicum annuum L cv. Vergasa) was grown under Pearl or black (control) nettings with 35% shading to compare their effects on postharvest fruit quality. Fully colored fruits were harvested four times from October to December, and after each harvest they were stored at 7 degrees C for 16 days, followed by 20 degrees C for 3 days. Compared with black netting, the Pearl netting significantly reduced water loss, decay incidence and titratable acidity, and increased fruit firmness, elasticity, ascorbic acid level and antioxidant activity, but did not change the external quality, except for a decrease in chroma. The effects of the Pearl netting were most pronounced on late-season-harvested fruits. Significant interactions were obtained between the shade netting type and harvest date. Analysis of correlations among the quality traits indicated that increased antioxidant activity and ascorbic acid content were tightly associated with the postharvest fruit quality attributes affected by the Pearl netting. Comparison between climatic parameters under the two netting treatments revealed no significant difference in air temperature and humidity, but the Pearl netting increased not only transmittance of long-waveband light but also light intensity within plant canopy. The findings suggest that the Pearl netting is more effective in maintaining postharvest sweet pepper fruit quality than the traditional black netting, especially at late-season harvests. The effects of the Pearl netting can be related to alteration of antioxidant levels induced by the pre-harvest light environment manipulation. (C) 2012 Elsevier B.V. All rights reserved.