Chemicals from Arid/semiarid Land Plants: Whole Plant Use of Milkweeds

The potential of arid/semiarid land plants a s sources of commercial products is illustrated by the following examples: candelilla (wax); jojoba (oil, protein); Acacia spp. (gum); Astragalus spp. (tragacanth gum); guayule (rubber); rabbitbrush (rubber, chemicals); sunflowers (rubber, chemicals); yucca (soap); and cresote bush (antioxidants, phenolic resins). co-evolutionary selection is a cause of the accumulation of secondary compounds in arid and semiarid plants. Although extraction of a single chemical might prove economically feasible for a few species, analyses involving extraction of multiple components and use of the extracted residue show that significantly greater value can be obtained by fractionation to attain whole-plant utilization. Although efficient laboratory methods to screen plants have been developed, only a few chemicals can be screened in the field. Additional research and development in field screening techniques are needed. Milkweed is a potential new chemical crop. The present stage of development is at the research, demonstration plot, pilot-plant phase. Milkweed is expected to be grown as a dryland crop in the western Great Plains using conventional farming machinery now used in alfalfa ‘hay production. Large-scale plantation farming would have an impact on imports of fuel and other commodities, By providing an alternative cash crop for the western Great Plains, milkweed farming could greatly strengthen the agricultural economy of the region.