Commercial biostimulants had minimal effects on greenhouse grown blueberry vegetative growth

Abstract

The drive to adopt sustainable practices in agriculture has led to the use of alternative products that either supplement and/or replace commonly used inputs. A nine-month greenhouse study was conducted to assess the effect of eight commonly used biostimulants on plant growth among four blueberry cultivars (‘Brightwell’, ‘Farthing’, ‘Legacy’ and ‘Premier’). The biostimulants did not show an effect on plant growth (i.e. height, width, volume, cane number, cane diameter, leaf area index) or plant biomass (dry weight). Similarly, no difference was detected between treated and untreated plants for the leaf pigment indicators (chlorophyll, anthocyanin, flavonols and NBI), with few exceptions. Terra Grow resulted in higher chlorophyll content than untreated plants in the cultivar Brightwell in February. Chlorophyll content was higher in the untreated plants than the biostimulant Fertiactyl GZ in ‘Legacy’ in May. Similarly, there were differences in anthocyanin and flavonols contents between the untreated plants and those treated with Terra Grow and Fertiactyl GZ in ‘Legacy’ and ‘Brightwell’ at two timepoints. However, the effects were not consistent over time or blueberry type. While biostimulants are often described as capable of providing benefits to plants in improving growth or alleviating biotic and abiotic stresses, such benefits were not evident with these products in a manner that was consistent in this study. Overall, the effects of the biostimulants considered in this study differed by blueberry cultivar and time and were not consistent.