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ARS Home » Southeast Area » Fort Pierce, Florida » U.S. Horticultural Research Laboratory » Subtropical Plant Pathology Research » Research » Publications at this Location » Publication #208586
Title: Raw plant material for cost-effective mass production of Dactylaria higginsii, a mycoherbicide for the control of purple and yellow nutsedges

Author
item YASSER, SHABANA - UNIVERSITY OF FLORIDA
item CHARUDATTAN, R. - UNIVERSITY OF FLORIDA
item KLASSEN, W. - TROPICAL REC
item Rosskopf, Erin
item MORALES-PAYAN, J. P. - UNIVERSITY OF PUERTO RICO

Submitted to: Florida Weed Science Society Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 10/11/2011
Publication Date: 2/26/2007
Citation: Yasser, S., Charudattan, R., Klassen, W., Rosskopf, E.N., Morales-Payan, J. 2007. Raw plant material for cost-effective mass production of Dactylaria higginsii, a mycoherbicide for the control of purple and yellow nutsedges. Florida Weed Science Society Proceedings.

Interpretive Summary:

Technical Abstract: Purple and yellow nutsedges (Cyperus rotundus and C. esculentus) are the most troublesome weeds in the cropping systems in Florida and the Caribbean, where they have been reported to cause yield losses of 20-89% in various horticultural crops. Conventional crop production systems are based on plastic mulching and methyl bromide soil fumigation for nutsedge suppression. When methyl bromide is phased out, the losses due to nutsedge competition are expected to increase in fumigation-dependent crops. Yields in organic production systems continue to suffer due to the lack of effective weed controls. A promising approach to nutsedge control is biological control with the fungus Dactylaria higginsii. For mass production of D. higginsii, 14 solid substrates in the form of dried, cut shoots/foliage of various plants were tested. These were tested alone or amended with 0.01% indol buteric acid (IBA), potato dextrose broth (PDB), or with PDB + 0.01% IBA. Conidial yield from these substrates was measured 4 and 12 weeks after inoculation. Those that were harvested after 4 weeks had a second spore harvest 4 weeks after the first harvest. Conidia were tested for virulence on purple and yellow nutsedges in the greenhouse. Conidial yields were highest when the fungus was grown on purple nutsedge hay without any amendments for 4 weeks. Conidia produced on purple nutsedge and sorghum hays were slightly larger and thicker walled than those produced on other hay media. Data on virulence of conidia will be discussed.