Biological Control of Red Alder (Alnus rubra) with the FungusNectria ditissima

Abstract

With few exceptions, north temperate North American weeds are native species that have proliferated following site disturbance. Social pressures are rapidly eroding the availability of essential silvicultural tools such as chemical herbicides and prescribed burning. Biological control with microorganisms in forestry is at an early stage of development. An inoculation strategy involving a fungus pathogen (PFC-082:Nectria ditissimaTul./ALDERKILL™), its formulation for biological control ofAlnus rubraBong. in the form of the PFC-MYCOCHARGE™and a newly devised instrument for bioherbicide delivery into woody stems (PFC-ALDERWAK™) are described. The overall strategy and implements are potentially useful for the delivery of any biological or translocatable material into amenity or orchard trees as well. PFC-082 was the single isolate ofN. ditissimatested that produced 100% infection and incited the formation of red alder cankers longer than 0.5 m in 30 mo when inoculated by the method described herein. Natural infections by this pathogen occur on fewer than 1% of red alder stems in the forest.