C4, (warm season) grasses can be monsters of structural biomass production (leaf and stem) and non-structural biomass production (grain and stem sugar). This is of interest for silage / feed, industrial feedstocks, biofuel production, and carbon sequestration. These crops include sorghum (structural, sugar, grain), sugarcane (structural biomass [energycane], stem sugar), miscanthus and switchgrass (structural biomass).
We tend to think of maize (Zea mays) as corn (which can refer to any grain crop). However, the diversity observed in domesticated maize (and even more so its wild relatives), suggest the improvement and use of Zea for structural biomass and/or sugar production may be possible. A long range project, there may be useable germplasm after 10-50 years.
Murray et al. (2008), reduced increased biomass in sorghum to a few separate factors to make up biomass per acre:
- Height (partially a function of flowering time / photoperiod sensitivity)
- Tillers or stems per unit area
- Stem diameter / leaf thickness & width
- Dry matter or density of stem and leaf
- Regrowth (ability to harvest multiple times within the same year)
There is variation for all of these traits within Zea.
Photos of highly tillering high biomass maize lines before flowering in Weslaco 2008 (below)