ARS | Publication request: Growth kinetics and efficacy as parameters for ranking and selecting biocontrol agents that reduce pink rot in stored potatoes

Submitted to: Potato Association of America Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: March 19, 2010
Publication Date: February 1, 2011
Citation: Adiyaman-Koltuksuz, T., Schisler, D.A., Slininger, P.J., Olsen, N. 2011. Growth kinetics and efficacy as parameters for ranking and selecting biocontrol agents that reduce pink rot in stored potatoes [abstract]. Potato Association of America. 88:29.

Technical Abstract: Increased production of organic agricultural products and the relative ineffectiveness of traditional control measures support development of new biocontrol technologies for use against pink rot infections in storage. The microbiota of 84 different agricultural soils was individually transferred to separate samples of gamma irradiation-sterilized field soil. After microbial community proliferation in these similar field soil environments, samples were assayed for biological suppressiveness to pink rot and zoospore production. The 13 most suppressive soil samples, which reduced zoospore production by 14% to 93% and disease severity on tubers by 6% to 21%, were used to isolate over 270 isolates of bacteria and yeast. Six bacterial strains significantly reduced the severity of pink rot by as much as 33% (P=0.05, FPLSD). Relative performance indices (RPIs) for efficacy and for each of four kinetic parameters including total colony forming units (cfu/ml, CFUmax), biomass production values (DWmax), cell production after 8 hours (OD8) and time of nutrient depletion (DT) were calculated for each strain. In addition, overall RPIs values for each strain were determined by combining efficacy (RPIEff) and kinetics (RPIKin) RPI values. Strains with the highest RPIEffKin possess both superior efficacy and liquid culture growth characteristics that suggest strong commercial development potential.