Effect of Plant Morphology and Planting Methodology On Biomass Production and Compositional Characteristics in Maize.

The ability to increase plant biomass and improve compositional traits such as digestibility is an ever-growing concern as the biofuel industry continues to grow.  Altering plant morphology and planting methodologies are two potential methods to increase biomass per unit of land.  It is hypothesized that both a tillering maize morphology and a planting regime which maximizes light interception by all plants will result in increased biomass production per unit of land.  To test these hypotheses, genotypes with varying degrees of tillering were evaluated at two different densities (20,000 plants ha^-1 and 70,000 plants ha^-1) and under two different planting methodologies; traditional row-crop planting with plants 0.2 meters apart within a row and approximately 0.8 meters between rows and equivalent distance planting with equal distance between plants within and between rows while still maintaining the same planting density (70,000 plants ha^-1).  Hybrids with variable corngrass1 penetrance were also evaluated to test the effect increased digestibility has on overall performance.  On a stover basis, increased tiller number resulted in increased yield and on a whole plant basis on increased NDF, ADF, and ADL.  Negative correlations were observed between stover yield and cell wall composition traits (NDF, ADF and ADL); while positive correlations were observed between NDF, ADF and ADL, indicating variation in the total cell wall rather than specific components.  Identifying developmental mutants with increased digestibility which maintain adequate yield will be crucial for the efficient production of biomass for the biofuel industry.