Drought assessment in wild blueberry production

Research trials were conducted in order to evaluate the impact of water availability and drought stress on the photochemistry, leaf gas exchange, and plant growth and development of the wild blueberry. As well, an assessment of the impact and feasibility of using various antitranspirants in wild blueberry production was performed. The drought treatment negatively affected the wild blueberry under greenhouse conditions by reducing stomatal conductance, photosynthesis, and light-adapted chlorophyll fluorescence at a SWP of approximately -2.7 MPa. By looking at a combination of the SWP, Pn, and light-adapted fluorescence results, a predawn SWP of -2.0 to -2.5 MPa was chosen as the point at which drought stress is detrimental to the carbon economy of the wild blueberry. Photosynthesis, light- and dark-adapted chlorophyll fluorescence were not negatively affected by the drought treatment under field conditions. On the contrary, under field conditions the floral zone length and number of flowering nodes of the wild blueberry were higher in the drought treatment when compared to the irrigation treatments. The wild blueberry continues to express itself as a drought tolerant species and therefore, it was recommended that, if necessary, irrigation would only be needed during the fruit filling stage of wild blueberry development.