Thesis (Ph. D.)--Southern Cross University, 2004. / Title from PDF title page (viewed on Sept. 24, 2005). Includes bibliographical references (p. 128-147).

Thesis (M.S.)--Boise State University, 2009. / Includes abstract. Includes bibliographical references (leaves 31-41).

Thesis (Ph. D.)--University of Hong Kong, 2000. / Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 1999. / Title from document title page. Document formatted into pages; contains ix, 84 p. : ill. Vita. Includes abstract. Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 1996. / Vita. Includes bibliographical references (leaves [139]-160).

Thesis (M.S.)--Boise State University, 2009. / Title from t.p. of PDF file (viewed June 7, 2010). Includes abstract. Includes bibliographical references (leaves 31-41).

Thesis (Ph.D.)--University of Hong Kong, 2000. / Includes bibliographical references. Also available in print.

Thesis (Ph. D.)--University of Chicago, Committee in evolutionary biology, Jun. 2003. / Includes bibliographical references (p. 227-244). Also available on the Internet.

Two field experiments were conducted at the Tidewater Agricultural Research and Extension Center, in Suffolk, Virginia, during summer 1994, on a Uchee loamy sand (fine, loamy, siliceous, thermic Arenic Hapludult) with relatively low water holding capacity. The objective was to determine the effect of plant population on yield, water use, and water use efficiency, of one cultivar of corn (<i>Zea mays</i> L.) and two cultivars of sorghum (<i>Sorghum bicolor </i>(L.) Moench). Plant population treatments for corn were 37, 49, and 62 thousand plants ha⁻¹ of cultivar Pioneer 3140 on a 91- cm inter-row spacing. For sorghum, treatments were factorial combinations of plant populations of 54, 109, 158, and 202 thousand plants ha⁻¹ and cultivars Dekalb-48 and Southern States 1212 on a 46-cm inter-row spacing. Experimental plots were laid out in randomized complete blocks with four replications. Soil water measurements were taken non-destructively at 10-day intervals after planting and at 20-cm intervals to a depth of 1.7 m in the center of each plot, using a Sentry AP-200 moisture probe. Overall mean grain yield for com was 3909 kg ha- l . For sorghum, it was 4800 kg ha-] for cultivar Dekalb-48 and 4740 kg ha⁻¹ for cultivar Southern States-1212. Soil water measurements showed that soil water stress occurred during tasseling of corn at 75 to 83 days after planting. This stress occurred just prior to the boot stage for sorghum at 60 to 68 days after planting. Crop water use, averaged over all treatments, was 494 mm for corn and 424 mm for sorghum. For corn, plant population did not influence grain yield and crop water use. Water use efficiency ranged from 0.748 to 0.873 kg m³. For sorghun1, there was no interaction between plant population and cultivar. Grain and dry matter yield, crop water use, and water use efficiency were similar for both the cultivars. Significant plant population effects were obtained for both sorghum cultivars. Grain and dry matter yield were depressed at the lowest plant population. Water use efficiency for sorghum increased non-linearly with increase in plant population from 0.944 to 1.354 kg m³. / Master of Science

Narrow row corn production has gained interest in the Mid-South region over the last several years. This narrow row spacing interest has been inspired by increase of soybean grain yield from narrow rows. Therefore, production practices were evaluated for proper management of narrow row corn production. Additionally, the management of glyphosate- and potentially auxin-resistant weeds place pressure on other POST chemistries. Therefore, optimizing glufosinate applications are essential for control of Palmer amaranth. The objectives of this research were four-fold: 1) evaluate the phenotypic and grain yield responses of narrow row corn production under irrigated conditions, 2) test corn hybrids for their response to increased plant population in a narrow row configuration in rainfed environments, 3) assess sidedress nitrogen fertilizer practices in narrow row corn production systems, and 4) further investigate glufosinate management for POST control of Palmer amaranth. The results of this research suggest few phenotypic changes by utilizing narrow rows in corn, but most importantly, a 0.7 Mg ha-1 increase in grain yield across all plant populations. Agronomic optimum plant populations for both irrigated and non-irrigated environments ranged from 101-120 thousand plants ha-1 with hybrids varying in their response to increased plant population. Additionally, sidedress nitrogen application methods of knife-in UAN vs. broadcasting treated urea responded similarly with respect to grain yield. Agronomic and economic optimum nitrogen rate would vary significantly by site. Regarding glufosinate management, smaller droplet sizes provided the greatest control of Palmer amaranth. In conclusion, these data suggest that narrow row corn production is a viable strategy to increase corn grain yield and seeding rates should be adjusted dependent on the corn hybrid of choice. Also, controlling Palmer amaranth in Dundee, MS with glufosinate was best utilizing smaller droplet sizes.