Is Breeding for Pest Resistance in Switchgrass a Viable Goal in North-Central Mississippi?.

Switchgrass (Panicum virgatum L.) continues to be examined as a full season biomass crop for bioenergy.  As a native grass of North America, a number of insect and fungal species exist that compromise yield in switchgrass stands.  Before the initiation of breeding efforts to ameliorate potential yield losses due to these pests, we must answer the question, what is compromising yield, and by how much?  Three pesticide treatments were imposed upon two 10 year-old ‘Alamo’ switchgrass stands.  Broad-spectrum systemic fungicide (azoxystroblin), systemic (acephate) + granular soil (bifenthrin) insecticide, and the combination of fungicide and insecticide were applied to plots at labeled rates.  Each replication had two untreated controls.  Treatments were initiated in fall 2013 so putative control would protect developing tillers during winter dormancy. Treatments were continued monthly during 2014, from the onset of switchgrass growth until mid-September.  A single end-of-season harvest was made to determine treatment effect.