The biostimulant effect of an extract from Durvillaea potatorum and Ascophyllum nodosum is associated with the priming of reactive oxygen species in strawberry in south-eastern Australia
S.W. Mattner, Oscar Villalta, Dylan McFarlane, Md Tohidul Islam, Tony Arioli, David M. Cahill
Abstract
Abstract Strawberry is an important horticultural crop in Victoria, Australia. Grey mould caused by Botrytis cinerea reduces marketable yield and post-harvest quality of strawberry fruit in the region. We conducted two field experiments in Victoria (Coldstream and Warburton) to evaluate the effectiveness of a commercial seaweed extract from Durvillaea potatorum and Ascophyllum nodosum (Seasol®) on the yield, revenue, and post-harvest rot of strawberry fruit. We applied the extract to strawberry crops (cv. Albion) monthly as a combined drench (10 L ha -1 ) and foliar spray (1:400), with water as a control. Application of the seaweed extract significantly increased strawberry fruit yields by 8-10% and revenue by AU$0.37-0.59 per plant. Furthermore, the extract significantly reduced the incidence and severity of post-harvest rots in strawberry fruit by 52-87%, respectively. The extract did not affect the firmness, soluble solids concentration (SSC), titratable acidity, or SSC:acid of strawberry fruit. In a separate laboratory experiment, we found that growing strawberry in the seaweed extract (1:400) increased the concentration of peroxidase by 50% and doubled H 2 O 2 in roots soon after treatment. Increases in reactive oxygen species are an indicator of a suite of pathways associated with resistance and tolerance of biotic and abiotic stresses. Overall, the results demonstrate that the seaweed extract can act as a commercially-viable biostimulant for strawberry fruit production in south-eastern Australia.