The effects of pH level and calcium carbonate on biomass and mineral uptake of blueberry grown in tissue-culture medium
In recent decades, there has been a dramatic increase in blueberry production in the soils best suited for that crop. Therefore, new plantations are now expanding into unfavorable soils (pH>5.5). It has been widely suggested that micronutrients become the limiting factor for plant growth under such conditions. The objective of this study was to examine the effects of pH and CaCO3 on biomass production and minerals uptake. Blueberry (Ochlockonee) plantlets were grown in tissue-culture medium at different pH levels: 6, 7, 8 and 5 controlled by 2 mM MES, BES, tricine and without biological buffer (5), respectively, with an additional treatment of 1% CaCO3 (pH~7). The shoot and root dry biomass decreased as the pH increased. No clear and consistent effect of pH on the micronutrients was observed. The dry biomass of the CaCO3 treatment was 50% of that observed for the treatment without CaCO3 at the same pH (pH 7). The plantlets grown with CaCO3 had greater concentrations of Ca in both their shoots (2-fold) and roots (6-fold), as compared to the plants grown without CaCO3. These results are in agreement with those we obtained in a hydroponic experiment, which showed that Ca accumulates on the surface of and inside blueberry roots under alkaline pH conditions. This Ca accumulation is probably due to precipitation with root exudates. These results suggest that micronutrient deficiencies are not the sole factor responsible for the damaging effects of alkaline-neutral pH conditions and CaCO3 on blueberry growth.
Tamir, G., Bar-Tal, A., Zilkha, S., Rotbaum, A., Oren, A., Freund, G. and Dai, N. (2019). The effects of pH level and calcium carbonate on biomass and mineral uptake of blueberry grown in tissue-culture medium. Acta Hortic. 1265, 203-210
blueberry, CaCO3, pH, culture medium, biomass production, mineral uptake