Possibilities for biological control of red core (Phytophthora fragariae)
Red core (Phytophthora fragariae) is a soil-borne pathogen of strawberry capable of surviving in soil for at least ten years. The pathogen was introduced into Finland via imported strawberry plants and was first detected in 2012. The Finnish climate of relatively low temperatures and high precipitation during the autumn enhances infection and damage caused by red core in perennial strawberry production. In addition to chemical control measures, biological alternatives already studied in crown rot (Phytophthora cactorum) control were tested against red core both in an open field and a greenhouse from 2014 to 2015. The effect of a mycorrhiza preparate Myko-Ymppi, an endophytic bacterium Pseudomonas fluorescens isolated from Finnish strawberry, and biofungicide Prestop® (Gliocladium catenulatum) were tested in a greenhouse experiment with young seedlings of Fragaria vesca 'Alexandria'. The plants treated with Prestop® developed best and had few red core symptoms during the 10-week trial, while no oospores of P. fragariae were detected in the roots. In the open field, treatment with Pseudomonas fluorescens was compared to phosphite (Restart) on strawberry cultivar 'Jonsok' in a red core infected field. The results showed that phosphite or mixed treatment with phosphite and endophyte could improve plant survival. However, the results are preliminary and red core control with alternative methods needs more investigation.
Parikka, P.K., Vestberg, M., Karhu, S.T., Haikonen, T. and Hautsalo, J. (2017). Possibilities for biological control of red core (Phytophthora fragariae). Acta Hortic. 1156, 751-756
strawberry, Phytophthora diseases, control methods