No abstract

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.

Blueberry plantation area is expanding rapidly inthere is a lack of knowledge on the fertilization for blueberry was executed in a commercial orchard of 6-year-old rabbiteye blueberry ('Brightwell') in 2017 and 2018, with four levels of compound fertilizer (N-P 2 O 5 -K 2 O: 15-15-15): 0, 300, 450 or 600 g plant -1 year -1 . It was found that the yields in 2017 and 2018 were 14.8~17.4 kg plant -1 and 13.9~16.2 kg plant -1 , respectively. The lowest yield was obtained at 600 g treatment, whereas the yield of the 300 g treatment in 2017 and 2018 was the highest and increased by 17.6% and 16.5% compared to the 600 g treatment, respectively. No and single berry weight. In 2017 and 2018, titratable acid content of blueberry in 600 g treatment was the highest. Total soluble solid content of blueberry than other treatments in 2017, but there were no Therefore, it was concluded that blueberry yield was highest by fertilizing with 300 g plant -1 year -1 without fruit quality decreasing, compared to the customary fertilization rate of 600 g plant -1 year -1 .

No abstract