New diseases in strawberry have been ascribed to Pestalotiopsis clavispora in the case of root and crown rot (of strawberry), first found in The Netherlands, and Pestalotiopsis longisetula in the case of leaf spots, such as leaf spot of strawberry and fruit rot reported mainly from Brazil. The genus is quite complex, so the taxonomy may change. Pestalotiopsis clavispora is also called Neopestalotiopsis clavispora.
Pestalotiopsis clavispora has been connected to strawberry diseases, but has also been linked to rose diseases.
Life cycle and appearance of Root and crown rot of strawberry
Not much is known about the life cycle. The fungus produces ascospores and conidia, but their role in the epidemic has not yet been established.
Pestalotiopsis clavispora is mostly found in plants that have been weakened by some form of stress, from underfertilization to water stress (either too much or too little water), or that are damaged by for example handling or pests. Optimum temperature for Pestalotiopsis clavispora is 19-23 °C and high humidity or free water stimulates disease development.
Pestalotiopsis clavispora causes discoloration or brown necrotic areas in crown and root of strawberry. Plant development is slow, growth is retarded and rooting is poor. Transplants look weak and may die. It is hard to visually distinguish between Pestalotiopsis clavispora and Phytophthora cactorum.
How to prevent Root and crown rot of strawberry
- Avoid stress:
- Take runner tips at the right stage to avoid stress and make plants less susceptible
- Avoid extreme temperatures and water levels in rootzone Avoid overhead irrigation, since it seems to increase disease development
- Provide balanced nutrition
- Avoid damage to the plants by pest insects or plant handling
- Take hygienic measures:
- Remove any infected plants in a plastic bag
- Clean trays, tools, gutters etc. between subsequent crops
- Disinfect water used for irrigation
Prevent plant diseases by optimizing plant potential and crop resilience.