Cuphea Production and Management - Industrial Crops: Breeding for BioEnergy and Bioproducts - page 288

important in the manufacturing of soaps and detergents, cosmetics, lubricants, and
certain nutraceuticals [ 1 ] but more recently have been shown to lend themselves
well for replacing petroleum in advanced biofuels and other bioproducts [ 2 ]. Except
for cuphea, there is currently no domestic crop source of oil rich in MCFA in the
United States. All MCFA used in the United States and most other developed
nations are derived from plant oils from coconut ( Cocos nucifera L.) and palm
kernel oil palm ( Elaeis guineensis Jacq.) imported from Southeast Asia and from
petrochemicals. The United States alone currently imports about 2.1 million metric
tons of palm-related oil at a cost of about $962 t 1 , which has been on the increase
since 2005 and is projected to continue to increase.
Considerable effort has been made to domesticate and improve cuphea's agro-
nomic traits to promote commercial production. Important breakthroughs were
made in the early 1990s by Knapp and Crane [ 3 - 5 ] toward reducing seed shattering
and seed dormancy in cuphea. Interspecific hybrids between C. viscosissima x
C. lanceolata ,f. silenoides populations were selected for partially non-shattering,
nondormant, and autofertile characteristics. From this selection process, the inter-
specific hybrid line PSR23 (PI 606544) was the latest released in 2000 [ 3 ]. The
cultivar PSR23 has been used in many agronomic studies to improve production
practices in recent years.
Furthermore, over the past decade, substantial progress has been made in
developing best management practices for cuphea PSR23 that have led to small-
scale production by the specialty seed industry [ 6 ]. Cuphea crop establishment has
been greatly aided by advances made in cuphea seeding requirements [ 7 - 12 ], weed
control [ 13 , 14 ], fertility [ 15 ], and harvesting [ 16 - 18 ]. However, harvest manage-
ment still remains a challenge largely due to cuphea's indeterminate growth and
propensity to shed seed (i.e., seed shattering), which are traits that will undoubtedly
require further crop breeding to improvement.
Cuphea Description and Origin
Cuphea genus (Lythraceae) is endemic to the New World with two major centers of
diversity located in southeastern Brazil and western Mexico. Cuphea species are
mostly summer-annual plants with some perennial species that grow from sea level
to 3,000 m elevation. In total, there are about 265 different species of the genus
Cuphea that have been identified, but only six species have their origin in the
United States [ 19 ]. Cuphea viscosissima Jacq. and C. lanceolata , which have been
used in the development of commercial cuphea lines, are annual herbaceous
species. Cuphea lanceolata is native to northern and Central Mexico, whereas
C. viscosissima is native to the United States with its general origin being along
the eastern United States inland from the coastal plains in disturbed, relatively wet
habitats [ 19 ]. Cuphea wrightii has been found in the southeastern corner of Arizona,
in disturbed, wet habitats, and its native range extends as far south as Costa Rica.
The other three species that have been found in the United States ( C. aspera,
C. glutinosa, and C. carthagenensis ) were introduced from South America [ 19 , 20 ].