EFFICACY OF BIOCONTROL AGENTS APPLIED TO BARE-ROOT CONIFER SEEDLINGS GROWN UNDER MINIMAL BUFFER ZONE RATES OF SOIL FUMIGATION
Project Number: 5358-12220-004-05
Specific Cooperative Agreement
Start Date: Sep 27, 2010
End Date: Mar 31, 2013
(1) Assess the efficacy of applied multiple biocontrol agents (e.g., Bacillus subtilis, Streptomyces lydicus, Gliocladium virens, and Trichoderma harzianum) to augment control of root pathogenic fungi (Fusarium, Pythium and Cylindrocarpon) in seedlings growing in soils treated with low levels of chemical fumigants (25-foot buffer rates using TIF tarps); (2) Apply PCR-based techniques to soil and seedling samples to assess Cylindrocarpon spp. present in PNW nurseries; (3) Quantify efficacy of various fumigants combinations on buried Cylindrocarpon inoculums; (4) Assess the economic viability of each treatment; and (5) Conduct educational outreach to project stakeholders
Four fumigant treatments (including an untreated control) will be applied at two forest nurseries according to a randomized complete block design with four blocks. Four biocontrol treatments (including an untreated control) will then be applied within each fumigant-treated plot for a total of sixteen treatments. Douglas-fir seedlings will be planted into each fumigant × biocontrol treatment plot and assessed for growth. Soil will be assayed by standard dilution plate procedures for the presence of Cylindrocarpon, Fusarium, and Pythium species before and after the application of fumigant and biocontrol treatments, and at the termination of the experiment. Weed populations will be quantified within each broader fumigation plot after Douglas-fir seedlings have been planted.