2007 Using Biological Controls to Reduce Root Disease

Project: Using biological control to reduce mortality of container Whitebark Pine seedlings caused by root disease in nurseries.

AttachmentDumroese _2007_ WBP biocontrol – NPJ

Agency/Forest or Park/District: USDA FS Rocky Mtn Research Station, Moscow, Idaho

Project coordinator: Kas Dumroese

Contact:  Kas Dumroese- USDA Forest Service, Rocky Mountain Research Station, 1221 South Main, Moscow 83843   208-883-2324   kdumroese@fs.fed.us

Cooperators Kent Eggleston- USDA Forest Service, Coeur d’Alene Nursery Robert L. James- USDA Forest Service, Region 1, Forest Health Protection Mee-Sook Kim- USDA Forest Service, Rocky Mountain Research Station.

Source of funding /amount

FHP: $5,000 Supplemental funding: $4,600 from USDA FS Southern Research Station; $9,600 from USDA FS Region 1, Forest Health Protection; and $8,000 form USDA FS Rocky Mountain Research Station, AND $1,800 from USDA FS Coeur d’Alene Nursery.

Dates of restoration efforts

Dates of the trials: year 2007


Reduce the negative impacts of root diseases during nursery production to enhance seedling quality, maximize seed-to-seedling ratios, and reduce propagation costs.

Acres/ha treated N/A


Inoculated WBP seedlings with potential biological controls and accessed their efficacy to control indigenous levels of root disease during  nursery production.

Planting? If so, source of seedlings? Resistance? No


The project was completed. Seedlings inoculated with Trichoderma harzianum (via PlantShield HC; BioWorks, Victor, NY), our potential Fusarium oxysporum biological control (Q12), and a combination of both Trichoderma harzianum and Fusarium oxysporum survived better than control seedlings when exposed to “background” levels of naturally occurring root disease in the greenhouse. Mortality for inoculated seedlings averaged 12% with no difference between biological control organisms, whereas mortality in the control was 30%.   We expected control seedlings subsequently inoculated with a known, virulent Fusarium commune (Q99) to show negative effects of root disease and we hoped to see some protection with the use of biological controls. Unfortunately, for unknown reasons, our pathogen (Q99) was, mostly, avirulent in this and other related studies. Subsequent reisolations of inoculum indicated the pathogen was viable, yet we observed no disease.

Monitoring since completion of the project    N/A                     

Plans for future monitoring?  


Will outcome meet goals?

Yes, application of a commercially available biological control reduced mortality by more than half.

Future actions/follow up?

Miscellaneous comments       

Results of this work were given at the 2007 Intermountain Container Seedling Growers’ Association Meeting and a paper was published in Native Plants Journal. It appears that the commercially available PlantShield is an effective biological control against “normal background” levels of root disease, and that our potential biological control (Fusarium oxysporum Q12) was equally effective.