1. Plant Polymer Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, 1815 N. University St., Peoria, IL 61604-3902. Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standards of the product, and the use of the name by the USDA implies no approval of the product to the exclusion of others that may also be suitable.
2. Corresponding author. E-mail: sellingg@ncaur.usda.gov