THE INFLUENCE OF BIOFUMIGATION ON MYCORRHIZAL FUNGI AND GROWTH OF STRAWBERRIES

Green manure from Brassica plants reduced the micro-organisms in the soil due to biocidal effect. Biofumigation with glucosinolates from Brassica juncea, Sinapis alba and Eruca sativa only partially influenced the mycorrhizal fungi of the strawberry cv. ‘Marmolada’. In the field trial the differences in mycorrhizal parameters were not statistically significant between treatments (Brassica juncea, Sinapis alba, Eruca sativa, dazomet, control). The highest frequency of roots with mycorrhizal fungi (F) was observed in the chemical treatment with dazomet (50.3%). In the control, F was 49.2% and it was the lowest in the B. juncea treatment (43.4%). In pot trials, the average F was found in B. juncea, 57.9%, followed by S. alba, 54.9%, E. sativa, 66.8%, dazomet, 2.9% and control, 60.8%. The average intensity of fungi infection (M) was found in B. juncea, 7.4%, then in S. alba, 9.8%, E. sativa, 7.5%, dazomet, 0.0%, and control, 7.1%. The growth of weeds differed a great deal between the trials. In the field trial the number of weeds was higher in the treatments with biocidal plants than with dazomet or in the control. In pot trials S. alba had the biggest influence on the germination of weeds. Differences in yield observed in the field trial were not statistically significant. In pot trials the number of fruits per plant was the highest in E. sativa (8.1), S. alba (7.0), B. juncea (6.9), control (3.7) and dazomet (1.8). Increase of the yield at the treatment with biocidal plants was the result of incorporation of organic matter into the soil and undisturbed activity of mycorrhizal fungi.