BIOTIC AND ABIOTIC FACTORS IN SOIL-BORNE DISEASES IN STRAWBERRY NURSERIES

Strawberry runners are a high-value cash crop in Spain that requires vigorous transplants free of pathogens. Ten different methyl bromide alternatives with an experimental randomized block design were applied, including methyl bromide and non-treated parcels in all the experiments like positive and negative controls since 1998 to 2007 in several strawberry nursery fields located in Castilla-León (Spain). Two field experiments where conducted each year with fumigant applications prior to planting. The results showed that more than 50% of the diseased symptomatic plants were not infected with soil borne pathogens. Furthermore, there are no correlations between the symptomatic plants without pathogens recorded and the treatment applied. Interaction between the symptoms produced by the main soil-borne pathogens in strawberry nurseries and other abiotic disorders was discussed, especially because the effect of chemical treatments against soil-borne pathogens can be overlapped.