Thesis (Ph. D.)--University of Texas at Austin, 2006. / Includes bibliographical references (p. 188-194). Also available via the World Wide Web: http://www.lib.utexas.edu/etd/d/2006/williamsj92964/williamsj92964.pdf#page=3

This paper deals with certain phases of phototropic properties of two exceptional plants, the pertinent behavior of each being decidedly individualistic and in remarkable contrast to that of herbaceous plants in general. The prickly lettuce, Lactuca ludoviciana (Nutt.) DC. and the rosinweed, Silphium laciniatum L., two common Denton County, Texas, plants, have been selected for this study.

Growing plants for feed or energy purposes in the Czech Republic is still a topic of concern. In this respect, mainly Zea mays L. is used. Growing Zea mays L. brings with it a number of environmental problems. One way to reduce these impacts is by replacing Zea mays L. with other plants suitable for these purposes. The alternative is to grow perennial energy plants. One of these may be the newly introduced species Silphium perfoliatum L. This work presents the results of the evaluation of the environmental aspects of growing Silphium perfoliatum L. for the purpose of obtaining phytomass compared to commonly used sowing techniques. The results are based on a 3-year follow-up in small field trials. The environmental burden related to the monitored cultivation procedures was evaluated on the basis of the LCA method within selected impact categories using the SimaPro v.7.3.2 software with the integrated ReCiPe Midpoint (H) method. According to the results, Silphium perfoliatum L. can be grown with generally lower environmental impacts than in the case of Zea mays L.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

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