Fungicide and Insecticide Effects On Switchgrass Establishment.

Switchgrass (Panicum virgatum L.) is currently a crop of interest in terms of bioenergy production. The objective of this study was to determine the effects of fungicide and insecticide switchgrass seed treatments on establishment. Field research was conducted in 2010 (Burneyville, OK, Athens, GA, and Eatonton, GA) and 2011 (Burneyville, Ardmore, OK, Athens, and Eatonton) on 9.3 m² plots. Seed treatments consisted of untreated check (colorant only), fungicide only (Proceed [prothioconazole + tebuconazole + metalaxyl]), insecticide only (Gaucho 600 [imidacloprid]), and fungicide - insecticide blends of Gaucho XT (imidacloprid + metalaxyl + tebuconazole) and Proceed + Poncho 600 (clothianidin) applied in six replications in May of each year. There were more seedlings (P < 0.0001) at 30 days after planting (DAP; 89 seedlings m²) than at 60 DAP (55 seedlings m²). At 50 DAP in 2011, there was no difference (P = 0.9) in seedling height between treatments (average 186 mm), but there was a trend (P = 0.08) toward greater percent stand with Gaucho XT and Proceed + Poncho 600 (36 and 35%, respectively) over the untreated check (19%). Applying both fungicide and insecticide to switchgrass seeds appear to improve establishment compared to untreated seeds, but further research under field conditions is warranted.