Defoliation management of switchgrass as a forage and bioenergy crop

Switchgrass can be used as a dual-purpose crop, as forage and bioenergy feedstock. Productivity, quality of the harvested herbage, and persistence of switchgrass were investigated as a function of frequency, intensity, and end-of-season defoliation. Intense defoliation regimes such us harvesting every 3 wk to ≥ 40-cm stubble height or every 6 wk to ≥ 20-cm stubble height are possible without compromising persistence of ‘Performer’ switchgrass but such management will result in 50% or greater reduction of dry matter yield compared to harvesting every 9 and 12 wk. Frequent defoliation will also result in greater digestibility and crude protein.   Although there are tradeoffs when managing for productivity or nutritive value, there is a wide range of defoliation management options for switchgrass that provide flexibility in terms of harvesting schedules and to optimize productivity and persistence as a forage or bioenergy feedstock.