Soil pH is a key factor affecting the growth of blueberries. Understanding the response mechanism of blueberries to different pH values and selecting suitable evaluation indexes are the basis of breeding new blueberry cultivars with high pH tolerances. The effects of different soil pH treatments for 17 months on the plant growth, fruit yield, photosynthetic characteristics, and leaf microelement concentration of Vaccinium ashei Reade ‘Climax’ and V. corymbosum hybrid ‘Chaoyue No. 1′ were studied. Plant height, main stem diameter, branch number per plant, leaf dry weight, stem dry weight, root dry weight, and total dry weight decreased with increasing soil pH. With an increase in soil pH, the first flowering date, 50% flowering date, first ripening date, and 50% ripening date of the two cultivars were postponed, and the flower bud numbers per plant, the floret numbers per bud, and yield per plant showed a downward trend. Moreover, the fruit quality decreased, which was reflected in the increase in the titratable acid content (TA) and the decrease in the total soluble solids content (TSS) and the TSS:TA ratio in the high pH treatment. With increasing soil pH, the chlorophyll content index (CCI), maximal photochemical efficiency of the PSII (Fv/Fm), quantum photosynthetic yield of the PSII (Y(II)) and net photosynthetic rate (Pn) of the two cultivars showed a downward trend, and some microelement concentrations in the leaves were imbalanced. Under high pH treatment, ‘Chaoyue No. 1′ had a relatively higher plant biomass and fruit yield, so it had a stronger tolerance to high pH than ‘Climax’ did. More strongly acidified rhizosphere soil capacity, as well as higher CCI, Fv/Fm, Y(II), and Pn values were the main reasons for the high pH tolerance of ‘Chaoyue No. 1′. Compared with destructive biomass indicators such as plant weight, nondestructive indicators such as CCI, Fv/Fm, and Y(II) can be more valuable indicators for fast and accurate evaluation of blueberry tolerance to high pH at early stages of treatment.

Aluminum (Al) is the major factor limiting plant growth on acidic soils. Blueberry (Vaccinum spp.) is an acidophilic plant. Highbush blueberry and rabbiteye blueberry are the main commercially cultivated species, while the response of which to Al is still unclear. Therefore, hydroponic experiments were conducted to determine the effect of Al (0 and 100 μmol L−1) on the growth and nutrient uptake of highbush blueberry ‘Brigitta’ and rabbiteye blueberry ‘Brightwell’. The results showed that root biomass, root length per fresh weight, root activity and foliar nitrogen (N) concentration of ‘Brigitta’ were significantly decreased by Al, while root lipid peroxidation was increased by Al. In contrast, the biomass and root activity of ‘Brightwell’ were not affected by Al treatment, root lipid peroxidation was significantly decreased, root length and surface area per fresh weight were increased compared with the control, which was benefic for nutrients absorption. In fact, foliar N concentration of ‘Brightwell’ was increased in Al treatments. However, fewer Al was accumulated in leaves of ‘Brightwell’ compared to ‘Brigitta’. Therefore, it could be concluded that growth and nutrients uptake of ‘Brightwell’ was not negative affected by Al, which meant ‘Brightwell’ was resistant to Al, compared to ‘Brigitta’.