3. Diagnosis and confirmation of Fusarium wilt 3.1. Diagnosis via culturing and isolation
For any crop, deploying effective controls and implementing integrated pest management (IPM) strategies depend on the ac- curate diagnosis of the disease. Diagnosis and confirmation of strawberry Fusarium wilt in the field is not possible, however. Strawberry is subject to at least four major soilborne pathogens that cause similar, if not identical, symptoms (Table 1). Poor growth, stunting, wilting and collapse of foliage, and plant death can be caused by Fof, Macrophomina phaseolina (causal agent of charcoal rot), Verticillium dahliae (causal agent of Verticillium wilt), and Phytophthora cactorum (causal agent of Phytophthora crown and root rot). Phytophthora crown and root rot differs from Fusarium wilt in that generally both younger and older foliage will collapse at the same time and the plant roots will be distinctly soft and rotted; Fof. However, charcoal rot of strawberry (Koike, 2008) causes symptoms that are identical to those of Fusarium wilt. Accurate field diagnosis of collapsing plants is therefore not possible to achieve without laboratory tests that mostly are based on the culturing and isolating of the causal agent.