Switchgrass and Giant Miscanthus Agronomy - Engineering and Science of Biomass Feedstock Production and Provision - page 45

Giant miscanthus ( Miscanthus × giganteus ) (Greef & Deuter ex Hodkinson &
Renvoize) is a warm-season perennial grass originally collected in 1935 in
Yokohama, Japan, that was then taken to Denmark where nurseryman Karl Foerster
grew it for landscape use [ 56 - 58 ]. Originally, M . × giganteus was classifi ed as a spe-
cies with names such as M. sinensis “Giganteus,” M. giganteus , or M. ogiformis
Honda , or M. saccharifl orus var. brevibarbis (Honda) Adati [ 53 ]. Research subse-
quently conducted at the Royal Botanic Gardens in Kew, England, determined
M . × giganteus to be a naturally occurring, sterile triploid hybrid of the diploid
M. sinensis and the tetraploid M saccharifl orus [ 59 ].
The grass possesses several desirable traits, including high yields, drought toler-
ance, frost tolerance and low-temperature growth in established plants, relatively
few pests and diseases along with good stress tolerance, and a positive energy
input-to-output ratio [ 53 ]. Conversely, concerns with giant miscanthus include its
need for asexual propagation, cold tolerance during the planting year, and variable
biomass composition depending on harvest timing, growing environment, and
nutrient inputs [ 53 ].
While it increases the cost of establishment, sterility in giant miscanthus is envi-
ronmentally desirable because the grass has a low risk of invading and naturalizing
in areas where it is unwanted. This differs from its fertile parents, M. sinensis and
M. saccharifl orus . Both of these species have invaded portions of the eastern USA
via seed spread, and because of its widespread horticultural landscape use,
M. sinensis is of particular concern [ 60 , 61 ].
Much of the bioenergy work in the USA employs the landscape clone of
M . × giganteus , now commonly called the “Illinois” type due to the extensive research
and production work conducted at the University of Illinois, Urbana-Champaign,
using this grass. The original landscape-demonstration planting of M . × giganteus at
the University of Illinois was made in 1988 from rhizomes obtained from the Chicago
Botanic Garden (Glencoe, IL) [ 62 ]. Since the early 2000s, this planting has supplied
giant miscanthus propagation material responsible for planting thousands of acres of
the grass in the USA and Canada for both research and production.
Recently, there has been a great deal of interest in developing additional types of
Miscanthus suitable for energy planting in order to increase biomass yields, reduce
inputs, extend planting regions, and improve pest resistance [ 63 ]. For example,
Repreve Renewables (Soperton, GA) markets a giant miscanthus, “Freedom,”
released by Mississippi State University researchers. Similarly, New Energy Farms
(Leamington, Ontario, Canada) offers “Nagara” giant miscanthus and reports it to
be extremely cold tolerant. Moreover, Mendel BioEnergy Seeds (Mendel
Biotechnology, Hayward, CA) works with sterile forms of giant miscanthus and
also with fertile Miscanthus spp. types capable of high biomass productivity. The
fertile forms offer less expensive planting and establishment, but have the potential
to become invasive via seed dispersal. At present, the seeded types are not commer-
cially available. Finally, Ceres, Inc. (Thousand Oaks, CA) is working with the
Institute of Biological, Environmental and Rural Sciences (IBERS) in Wales to also
develop seeded Miscanthus spp. for bioenergy, as well as increase Miscanthus spp.
genetic diversity and tolerance to harsh environments.