Browsing by Subject "varastoporkkana"

Plant production and especially food production faces constantly challenges due to plant pathogens. Plant pathogens, such as different kinds of pathogenic fungi, are controlled throughout the production chain. Several vegetables, including carrot (Daucus carota), can get damaged during long storage periods. For example, temperature and moisture of the storage environment in addition to microbes, affect the quality. The crop losses caused by harmful microbes might be reduced by using biological control methods. The aim of this study was to evaluate if fungal pathogens could be suppressed in stored carrots by biological control. The biological control agent used in this study contains Clonostachys rosea J1446 fungus, which has been tested to be effective against many fungal plant pathogens. Three carrot batches were sprayed with C. rosea J1446 suspension. The carrots were stored in cold storage (0.5 °C) from four to six months. After the storage period, the number of infected carrots was counted and the amount of crop loss was measured. In addition, the survival of C. rosea J1446 fungus on the carrots was examined during the storage period. Pathogenic fungi were identified by molecular biology methods and by morphological features. Some of the fungi were selected for dual culture test examining antagonistic effects of three Clonostachys strains. In this study, the amount of diseased carrots was approximately 33 % of the untreated carrots. Symptom in the tip of the carrot was the most common indication of a disease. Treatment with C. rosea J1446 suspension reduced the amount of diseased carrots by 23 % on average and the treated carrots had less weight loss after the storage period. Viable C. rosea J1446 fungus was isolated from the carrots after six months. Most common pathogens found from the disease symptoms were Botrytis cinerea, Cylindrocarpon spp., Fusarium spp. and Mycocentrospora acerina. The results of the antagonism test showed that the three Clonostachys strains reduced the growth of these pathogens. The results of this research indicate that the C. rosea J1446 product could be used as a biological control agent against fungal pathogens on storage carrots.