Evaluation of narrow corn (Zea mays L.) production and management in Mississippi and management of glufosinate herbicide applications on Palmer amaranth (Amaranthus palmeri) control in cotton (Gossypium hirsutum)
Mississippi State University
Date of Degree
Original embargo terms
Dissertation - Open Access
Doctor of Philosophy
College of Agriculture and Life Sciences
Department of Plant and Soil Sciences
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.
Mississippi Corn Promotion Board
Williams, John Joseph, "Evaluation of narrow corn (Zea mays L.) production and management in Mississippi and management of glufosinate herbicide applications on Palmer amaranth (Amaranthus palmeri) control in cotton (Gossypium hirsutum)" (2021). Theses and Dissertations. 5165.