Evaluation of Bioenergy Traits in Ten Populations of Switchgrass Grown in New Jersey.

Switchgrass (Panicum virgatum L.), a perennial warm season grass (C4) native to most of the US, is currently being developed as a biofuel crop.  Since no single switchgrass cultivar is likely to have yield advantages across all locations, it will be important to identify germplasm specifically for the northeastern and mid-Atlantic regions of the US.  Switchgrass is an outcrossing, self-incompatible polyploid species with a high degree of genetic diversity and two distinct ecotypes, upland and lowland, which differ in growth habit and habitat adaptation.  The objective of this study was to evaluate biomass characteristics of ten switchgrass ecotypes grown in New Jersey.  Ten switchgrass populations were planted in a spaced-plant nursery in the spring of 2006 at the Rutgers University Plant Biology Research and Extension Farm at Adelphia, NJ.  Plants were evaluated for two years (2007 and 2008) for several characters contributing to biomass yield including: winter injury, disease, lodging, maturity, tiller density, plant height, and biomass yield.  Significant differences were observed between ecotypes under New Jersey growing conditions.  Lowland cultivars were taller and matured later than upland ecotypes.  The earliest upland ecotype Brooklyn had anthesis dates (Julian) of 202.1 in 2007 and 206.2 in 2008 while the latest lowland ecotype SL93 had anthesis dates (Julian) of 232.3 in 2007 and 247 in 2008.  Typically, lowland populations had greater biomass yields than upland populations.  Timber, an eastern lowland ecotype had one of the highest mean biomass yields (758.7 g dry biomass/plant) with tall plants and median winter injury, tiller density, maturity, disease, and lodging, making it a promising population for biomass production in the mid-Atlantic and northeastern regions of the US.