Brief Summary of Minutes of Annual Meeting

Alaska (Univ of Alaska - McBeath) Plant Helperâ, a formulated Trichoderma atroviride, continues to demonstrate that it is efficacious in the control of Armillaria root rot of fruit trees. Also, eighteen gram positive bacteria, were found to suppress the growth and development of Sclerotina sclerotiorum and Rhizoctonia solani. All of these bacteria isolates grow well in high temperatures (>37 ºC) and twelve grew well at 4 ºC. These bacteria isolates seem to be compatible with T. atroviride. Finally, T. atroviride, a cold tolerant strain, produces a coordinated biochemical response in the presence of different plant pathogens. Our studies indicated that T. atroviride produces cell-wall degrading enzymes at both 22 and 7 C. Arizona (Univ of Arizona - Pierson) Characterization of phenazine regulation and functions in P. aureofaciens 30-84 continues to provide insights into rhizobacterial environmental and community sensing. Molecular and ecological approaches are being used to determine the roles of phenazine antibiotics on biofilm development, root colonization, cell signaling, and pathogen inhibition. California (UCR-Becker) Our research collaboration has developed and optimized research strategies that are applicable to a number of different projects, all dealing with biologically-caused suppression of growth/development of other organisms. With our focus on the identification of the causal agents of nematode population suppression, Prunus replant, and Rhizoctonia damping-off suppression, we attempt to provide the basis for addressing important challenges in agriculture. California (UCR-Borneman) We have identified fungi whose population densities were negatively associated with rootknot nematode population densities. Additionally, we created a series of soils with various levels of peach replant suppression. We are now in the process of performing rRNA gene-based studies to identify the microorganisms involved in these phenomena. California (UCR-Stangellini) Larval stages of shore flies and fungus gnats were shown to ingest and excrete viable oospores of Pythium aphanidermatum, hyphal swellings (sporangia) of P. ultimum, P. splendens, and P. sylvaticum and chlamydospores of Phytophthora ramorum but not sporangia of P. parasitica, P. ramorum or P. capsici. With the exception of oospores of Pythium aphanidermatum, adult shore flies were able to ingest but not excrete viable propagules of any of the oomycetes assayed. Adult fungus gnats did not ingest propagules of any oomycete. Land snails were also demonstrated to ingest and excrete viable chlamydospores, but not sporangia, of P. ramorum. California (UCD-Subbarao) Evaluation of the effects of brassica cover crops on soilborne diseases of strawberries and efficacy of Coniothyrium minitans (commercial product Contans) on lettuce drop caused by Sclerotinia minor are being tested in large experimental plots in California. Preliminary results suggest both to be sustainable non-chemical approaches for soilborne disease management. Montana (Montana State Univ. - Jacobsen) Muscodor albus mycofumigation or use of biorational synthetic M. albus gases has shown potential to control nematodes and a wide range of soil fungal genera including Rhizoctonia, Pythium. Streptomyces, Colletotrichum, and Verticillium. Practical control of several potato diseases caused by these soil microbes has be demonstrated in the field. Nebraska (Univ. of Nebraska - Yuen) Lysobacter enzymogenes C3, a biocontrol agent of plant pathogenic fungi, was found to reduce numbers of the sugarbeet cyst nematode feeding on sugarbeet roots and to promote the growth of sugarbeet plants. This discovery could potentially lead to an environmentally friendly method for managing plant parasitic nematodes. An antibiotic complex produced by C3 was found to be toxic to nematodes. This information could be important in developing and improving C3 as a biocontrol agent. Collaborative research among members of W1147 could eventually lead to better understanding of native population distributions of Lysobacter and how they might be enhanced for disease management. New York (Cornell Univ, NYSAES - Abawi) In 2007, over 1000 soil samples collected from commercial fields, research and demonstration sites were processed for soil health status http://soilhealth.cals.cornell.edu One focus was on relating the collected soil health data, especially root health measurement, to yield and other productivity factors. For example, plots of the vegetable production systems (Conventional, Organic, IPM  Present, and IPM  Future) of the Cornell/NYS IPM Program that have been ongoing since 1995 were planted to snap beans in 2007. Although the data is not statistically significant, the yield of beans grown in the IPM  Future plots had the highest total and marketable bean yield. Previous results of the soil bioassay with beans had also shown that root health is highest (root rot severity is lowest) on roots of plants grown in plots of the Future  IPM system. New York (Cornell Univ, NYSAES - Smart) We are studying the effect of multiple plant activators on field-grown tomatoes to determine if induced systemic resistance (ISR)-inducing biocontrol agents are compatible with other systemic acquired resistance (SAR)-inducing compounds. Utilizing both SAR and ISR-inducing compounds, we have found that SAR-inducing compounds are more effective at controlling foliar diseases of tomato. ISR-inducing Bacillus sp. have increased yield in fresh market tomato varieties. Importantly, when both SAR and ISR compounds are applied to the tomato plant, there is no reduction in disease control. Additionally, a DNA-based macroarray was developed which can detect over 40 fungal and oomycete pathogens simultaneously. Ohio (The Ohio State Univ  McSpadden-Gardener) By increasing our understanding of the influence of farm management and soil chemistry on biocontrol populations as well as pathogens, we hope to quantify the relative advantages and disadvantages of different practices in terms of their effects on natural biocontrol potential of soils. Identification of novel disease suppressing microorganisms will provide new options for the development of biopesticides to replace methylbromide and other restricted use chemicals with greater toxicity to non-target organisms. Washington (USDA-ARS, Pullman - Paulitz) Phenazine, an antifungal compound produced by Pseudomonas spp., may play an important, but unrecognized role in Rhizoctonia suppression in PNW cereal cropping systems. The biogeography of Pythium and Rhizoctonia in cereal systems is being better understood, especially the influence of soil type, rainfall zone, and cropping system. Conservation fallow may provide a cultural management method for Rhizoctonia in low rainfall zones. Timing of greenbridge sprayout in the spring can reduce damage by Rhizoctonia.