Dry matter partitioning and quality of Miscanthus, Panicum, and Saccharum genotypes in Arkansas, USA

The partitioning and quality of aboveground biomass have important ramifications for crop management and biomass conversion. In preliminary studies, Saccharum sp. x Miscanthus sp. hybrids exhibited stubble cold tolerance in west-central Arkansas, unlike Saccharum sp. x Saccharum spontaneum hybrids. The objective was to examine foliar and stem quality of the C4 grasses Miscanthus sinensis ('Gracillimus'), Miscanthus x giganteus (Q42641, proprietary), Panicum virgatum ('Alamo'), and two F1 hybrids of Saccharum sp. x Miscanthus sp. (US84-1028 and US84-1058) in a field study during 2004 (plant cane) and 2005 (first stubble) near Booneville, AR. Switchgrass produced more stems m-2 than the other entries both years, and there was little difference in stem number among other entries. Clone US84-1028 yielded more dry mass m-2 than other entries in plant cane, while switchgrass, US84-1028, and M. x giganteus did not differ in first stubble. Clone US84-1028 also had more stem dry mass and leaf dry mass than other entries both yr. Tissue N concentrations were low for these entries, but leaves contained about twice the N of stems (≤15.2 and 7.8 g kg-1, respectively). Leaves represented as much as one-third of total biomass, and had large cellulose (≤482 g kg-1) and lignin (167 g kg-1) concentrations. The competitively high biomass yield of this small sample of sugarcane alleles should encourage the expansion of the crop beyond its current production regions. Sugarcane and M. x giganteus should be examined in higher-input temperate systems because of their bioenergy potential