Browsing by Author "Laamanen, Tuija-Liina"

Carrot production is very specialized and professional in Finland. Long term storage of the yield is necessary during winter. In storage, the resistance of carrots to diseases decreases even with optimized storage conditions. Diseases can cause huge losses during long storage periods, but the severity of losses varies between years and fields. One of the most harmful diseases of carrots during storage is Mycocentrospora acerina. It is a soil borne fungus that cannot be controlled by fungicides. This is a study of the test method to evaluate the risk of M. acerina in a field. In this test slices of carrots were placed in a container with collected soil samples from a test field. The containers with soil samples and carrot slices were kept six weeks in the dark at +15 °C temperature. After that it was possible to see if M. acerina had grown up from the soil and infected the carrots by forming dark colored patches to the carrot slices. By calculating and comparing the amount of patches on each soil sample it was possible to evaluate the risk of M. acerina in a test field. Results from the test were compared to amount of M. acerina infection found in stored carrots harvested from the same fields. The study showed that it is possible to evaluate the risk of M. acerina. Soil samples can be collected in different times of the year, and the test can be made with fresh or storage carrots. The test samples need to be comparable, so they must be collected the same way and the amount of samples in each container must be sufficient to minimize variation. This study will introduce simple guidelines that farmers can use to test fields and evaluate the risk of M. acerina.