ARS | Publication request: Production and application of the bioherbicide agent Dactylaria higginsii on organic solid substrates

Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 11, 2011
Publication Date: May 31, 2010
Citation: Shabana, Y.M., Charudattan, R., Aboutabl, A.H., Morales-Payan, J., Rosskopf, E.N., Klassen, W. 2010. Production and application of the bioherbicide agent Dactylaria higginsii on organic solid substrates. Biological Control. Biological Control 54:159-165.

Technical Abstract: Purple nutsedge and yellow nutsedge are serious weeds in Florida and in many parts of the world and Dactylaria higginsii is a promising bioherbicide candidate for these weeds. As an alternative to liquid fermentation for mass production of D. higginsii, 19 solid substrates were tested including dried, cut culms or foliage of 14 different plants prepared as hays, sugarcane bagasse, a commercial peat-based microbe carrier (BioAPT), and two recycled papers (kraft paper and newspaper). These substrates were tested alone or amended with 0.01% indole butyric acid (IBA), which enhances growth and/or sporulation of D. higginsii, potato dextrose broth (PDB) for nutrient amendment, or PDB+IBA. Yield of D. higginsii conidia produced on these substrates was measured 4 and 12 weeks after inoculation. Conidia were tested for virulence on purple and yellow nutsedges in the greenhouse. Hays without amendments or amended with PDB yielded more conidia which were also more virulent (= aggressiveness) than those produced on hays amended with IBA. Conidial yields were highest when the fungus was grown on purple nutsedge hay without amendments for 4 weeks but conidia produced on this medium had low virulence. Conidia produced on sorghum x sudangrass and cogongrass hays were slightly larger and thicker walled than those produced on other substrates. Conidia produced on sorghum x sudangrass were the most virulent on nutsedge seedlings. Purple nutsedge was more susceptible to D. higginsii than was yellow nutsedge. Cogongrass and sorghum x sudangrass hay substrates offer a suitable and easy medium for large-scale production of D. higginsii.