Morphological and Physiological Responses of Wild Blueberry ( Vaccinium Angustifolium Ait) to Irrigation Frequency and Precipitation Scenarios

Commercial wild blueberry (Vaccinium angustifolium Ait.) production is influenced by precipitation amount, distribution, and timing. The state of Maine (U.S.A.) has experienced an increase in annual precipitation over recent decades, a trend that is projected to continue. How wild blueberries, an economically and culturally important fruit crop in Maine, will respond to these changes is not well-understood. Here, we use historical precipitation observations from the Parameter-elevation Regression on Independent Slope Model (PRISM) to develop scenarios for current and probable future precipitation patterns. Three greenhouse treatments reflected recent dry and wet historical scenarios, and one plausible future scenario. In a second greenhouse experiment, we tested three different irrigation frequency treatments. We find that the total amount and seasonal distribution of precipitation have noticeable, though uneven, effects on wild blueberry morphology and physiology. Our findings suggest that precipitation influences stem length, though we found no statistically significant effect on branching. High irrigation frequency increased stem length relative to low and medium irrigation frequency, while branching patterns were largely unaffected. It is anticipated that a changing climate will likely lead to changes in wild blueberry development and productivity, although responses may vary among genotypes. To better understand the effects of climate change on wild blueberries, future research should further evaluate the interactive effects of precipitation and temperature in a field setting.