Reflective mulch increases fruit yield of highbush blueberry (Vaccinium corymbosum L. cv. Darrow) grown in a northern maritime environment while maintaining key fruit quality traits.

BACKGROUND: In maritime growing environments, blueberry yield often exhibits excessive season-to-season variation, associated with poorly adapted photosynthetic responses to low light conditions. It is therefore necessary to develop methods that stabilise yield while maintaining or improving fruit quality. Here, we placed reflective mulch alongside plants at the early green fruit stage, to test the hypothesis that increasing the available seasonal light integral could enhance blueberry yield. We further determined several quality characteristics to ensure fruit marketability. RESULTS: Placement of mulch alongside plants reflected up to five times more light compared with bare ground, enhancing the amount of light reaching the canopy. This led to an adaptive increase of light saturated maximal photosynthetic rate of mulch-treated plants, resulting in a twofold increase in yield compared with control plants. Analysis of fruit quality characteristics showed that total soluble solids, sugars and organic acids were similar between treatments. Likewise, antioxidant capacity, total anthocyanin content and the content of individual anthocyanins did not change in response to reflective mulch treatment. CONCLUSIONS: The use of reflective mulch should be explored by industry as a cost-effective method for enhancing blueberry yield while maintaining fruit quality in maritime environments. © 2020 Society of Chemical Industry.