Biofumigation of a Strawberry Matted-Row Site with Brassica Green Manure Cover Crop

Brassica napus cultivars ‘Plainsman’, ‘Sumner’ and ‘Wichita’ were seeded in September 2006 on ground that previously grew matted-row strawberries.  These cover crops were used as an alternative to chemical fumigants prior to replanting the site to strawberries.  Control plots (previously and not-previously planted to strawberries) were seeded to Secale cereal, grain rye in October 2006.  Soil was a Viraton cherty silt loam with a fragipan in the subsoil, typical for the Ozark region of Missouri.  Both cover crops were incorporated in late March 2007 and strawberries planted in May.  The experiment was a split-plot design with four replications.  Strawberry cultivars were Allstar, Annapolis, Brunswick, Eros and Mesabi.  Nematode populations showed no differences in harmful species among treatments.  Strawberry crown counts showed no differences among treatments for four of the five cultivars.  Only Eros had highest crown counts in the control (not-previously planted to strawberries).  Visual canopy rating showed the more vigorous strawberry plants in this control for all cultivars except Mesabi.  Total yield showed Sumner and Wichita not different from the control (previously planted to strawberries).  Plainsman had lowest total yield.  Average berry weight showed little difference among the treatments.  Only the control (not-previously planted to strawberries) had highest average berry weight.  The lack of treatment affect for Brassica cover crops used as biofumigants indicated that damaging nematodes were not a limiting factor in this strawberry replant site.