Soybean accounts from more than half of the acres dedicated to row crop production in the mid-south, leading to a wide planting window from late-March through mid-July. Studies were conducted in 2013 and 2014 evaluating seven planting dates of soybean, and their impact on agronomics. As planting was delayed, plant heights significantly increased, increasing the potential for lodging. Canopy closure significantly decreased as planting was delayed, leaving soybean more vulnerable to caterpillar pests. Yield potential also significantly decreased as planting was delayed. Season long surveys of insect pests and their arthropod natural enemies were conducted from 2013 to 2014 in small plot studies, and in large plot studies from 2015 to 2016 across multiple planting dates. The most common insect pests encountered in both studies were bean leaf beetles, the stink bug complex, and soybean looper. The most common natural enemies encountered were lady beetles, spiders, and the assassin bug complex. In general, insect pests densities increased as planting was delayed, whereas natural enemies were higher in earlier plantings or had no change throughout the planting windows. With the increased difficulty of controlling some caterpillar pests such as soybean looper, new control tactics need to be evaluated. A simulated Bt treatment was evaluated against a threshold, bug only, and untreated control across multiple plantings in 2013 and 2014. The simulated Bt treatment yielded significantly higher than the untreated control at plantings from early-June through mid-July. These were the only plantings that reached action threshold for soybean looper. The simulated Bt and threshold treatments were not significantly different from one another. In 2015 and 2016, a simulated Bt treatment plus threshold was evaluated in a late planting situation. The simulated Bt plus threshold treatment yielded significantly higher than the untreated control at the early-June and early-July plantings. Also in 2015 and 2016, the simulated Bt treatment was evaluated against a grower check on producer fields at 23 locations. The simulated Bt treatment resulted in significantly higher soybean yields than the grower check.

Magister Artium - MA / For an Island measuring merely 128 square kilometers, and in spite of its remote location in the mid-­South Atlantic, St. Helena “punches way above its weight in history”, earning and occupying a privileged place in British scholarship of its imperial thalassocratic age. However, prior to this period in which the Island was indispensible to British Empire formation, it had passed through the hands of at least two former European naval nations before it was eventually laid claim to and effectively colonised by the British. The Portuguese, who were the first to stumble upon the uninhabited Island in 1502 -­ naming it St. Helena in honour of Roman Emperor Constantine the Great’s mother -­ managed to keep its existence a closely guarded secret for over eight years. For nearly a century, the Island was reserved for exclusive use by the Portuguese as a port for recuperation, replenishing and re-­provisioning, which they usually visited on their homebound journey from trading (and conquering) in the East Indies. This Portuguese monopoly of use of the Island, however, ended during the last decade of the sixteenth century when other maritime nations, particularly Dutch and later English traders, became aware of and started frequenting the Island. The initial overlap period, constituting the first three decades of the seventeenth century when mostly the Dutch and Portuguese shared use of the Island, was cause for occasional hostile encounters between the two nations. Apparently, continued Dutch and English harassment of Portuguese (and Spanish) ships made visiting the Island untenable for the Portuguese who opted to avoid St. Helena and instead make use of a number of their other port ‘possessions’ along the West African coastline to replenish and repair their ships.

Oak savannas are among the most imperiled ecosystems in the United States as a result of habitat degradation and consequently, associated vegetation and wildlife communities have also declined. I evaluated savanna restoration strategies on twelve case studies in Tennessee and Kentucky. These case studies represented a broad range of disturbances and the most advanced savanna restoration sites within the region. I evaluated vegetation and breeding bird responses to landscape and overstory conditions across sites through a meta-analysis. Total grass and forb cover were influenced by overstory metrics but not by topography (P >0.05). Oak regeneration density was influenced by canopy cover, while oak competitor regeneration density was influenced by percent slope and sapling density (P <0.05). With respect to breeding birds, I found forest species persisted within case studies despite substantial disturbance; shrub/scrub birds were common on disturbed sites. Only three obligate grassland bird species, Tyrannus tyrannus, Aimophila aestivalis, Spiza americana, were observed on my sites. Relative abundance of Passerina cyanea was positively related to the groundlayer development; whereas that of Melanerpes erythrocephalus was positively related to basal area of dead trees (P <0.05). Based on my results, canopy reduction and growing-season burns may both be critical for the restoration of savannas within the region. Drum-chopping is a tool that may expedite oak savanna restoration through improved woody competition control, however, its effectiveness has not been investigated. Therefore, I evaluated drum-chopping effects on vegetative structure at Catoosa Wildlife Management Area, Tennessee, during 2008 and 2009 using two adjacent sites with similar fire and overstory removal histories. One site was subjected to drum-chopping in September of 2007, while an adjacent site (control) was not chopped. Drum-chopping reduced grass and forb cover, and oak seedling density, but increased bare ground and density of vines and shrubs versus the control (P <0.05). Except for bare ground, differences were no longer apparent in the second year. Based on my results, drum chopping may reduce midstory vegetation too thick to be effectively controlled by fire, but otherwise has limited utility as a restoration tool. Although wildlife managers have tried to restore savannas using prescribed fire and overstory canopy removal, use of other tools may be warranted. One such method is drum-chopping, which has been used elsewhere to reduce woody competition. However, the effectiveness of this method in restoring oak savannas has not been evaluated. Therefore, I evaluated drum-chopping effects on plant composition at Catoosa Wildlife Management Area on the Cumberland Plateau in Tennessee. Two adjacent sites with similar fire and overstory removal histories were selected for this study. One of these sites was subjected to drum-chopping (CHOP) in September of 2007, the adjacent site was not chopped (NOCHOP). Grass cover differed by treatment (P <0.01) and year*treatment (P = 0.03). Forb cover differed by treatment (P <0.01) and legume cover differed by year (P <0.01), treatment (P <0.01), and year*treatment (P = 0.01). Exposed bare ground differed by year (P <0.01) and treatment (P <0.01). Exposed leaf litter differed by year (P <0.01). Vines and shrubs (<1.37m tall) differed by treatment (P <0.01). Oak seedling (0-30.48 cm tall) densities differed by treatment (P = 0.05). Based on my results, drum chopping may be a valuable tool where woody encroachment has become too thick for fire to be effective or herbicides are not a viable option, but otherwise has limited utility as a tool for oak savanna restoration.

Oak savannas are among the most imperiled ecosystems in the United States as a result of habitat degradation and consequently, associated vegetation and wildlife communities have also declined. I evaluated savanna restoration strategies on twelve case studies in Tennessee and Kentucky. These case studies represented a broad range of disturbances and the most advanced savanna restoration sites within the region. I evaluated vegetation and breeding bird responses to landscape and overstory conditions across sites through a meta-analysis. Total grass and forb cover were influenced by overstory metrics but not by topography (P >0.05). Oak regeneration density was influenced by canopy cover, while oak competitor regeneration density was influenced by percent slope and sapling density (P <0.05). With respect to breeding birds, I found forest species persisted within case studies despite substantial disturbance; shrub/scrub birds were common on disturbed sites. Only three obligate grassland bird species, Tyrannus tyrannus, Aimophila aestivalis, Spiza americana, were observed on my sites. Relative abundance of Passerina cyanea was positively related to the groundlayer development; whereas that of Melanerpes erythrocephalus was positively related to basal area of dead trees (P <0.05). Based on my results, canopy reduction and growing-season burns may both be critical for the restoration of savannas within the region. Drum-chopping is a tool that may expedite oak savanna restoration through improved woody competition control, however, its effectiveness has not been investigated. Therefore, I evaluated drum-chopping effects on vegetative structure at Catoosa Wildlife Management Area, Tennessee, during 2008 and 2009 using two adjacent sites with similar fire and overstory removal histories. One site was subjected to drum-chopping in September of 2007, while an adjacent site (control) was not chopped. Drum-chopping reduced grass and forb cover, and oak seedling density, but increased bare ground and density of vines and shrubs versus the control (P <0.05). Except for bare ground, differences were no longer apparent in the second year. Based on my results, drum chopping may reduce midstory vegetation too thick to be effectively controlled by fire, but otherwise has limited utility as a restoration tool. Although wildlife managers have tried to restore savannas using prescribed fire and overstory canopy removal, use of other tools may be warranted. One such method is drum-chopping, which has been used elsewhere to reduce woody competition. However, the effectiveness of this method in restoring oak savannas has not been evaluated. Therefore, I evaluated drum-chopping effects on plant composition at Catoosa Wildlife Management Area on the Cumberland Plateau in Tennessee. Two adjacent sites with similar fire and overstory removal histories were selected for this study. One of these sites was subjected to drum-chopping (CHOP) in September of 2007, the adjacent site was not chopped (NOCHOP). Grass cover differed by treatment (P <0.01) and year*treatment (P = 0.03). Forb cover differed by treatment (P <0.01) and legume cover differed by year (P <0.01), treatment (P <0.01), and year*treatment (P = 0.01). Exposed bare ground differed by year (P <0.01) and treatment (P <0.01). Exposed leaf litter differed by year (P <0.01). Vines and shrubs (<1.37m tall) differed by treatment (P <0.01). Oak seedling (0-30.48 cm tall) densities differed by treatment (P = 0.05). Based on my results, drum chopping may be a valuable tool where woody encroachment has become too thick for fire to be effective or herbicides are not a viable option, but otherwise has limited utility as a tool for oak savanna restoration.

Neonicotinoid seed treatments are widely used and highly effective against early season insect pests of all row crops throughout the Mid-South region of the United States. An analysis was performed to determine the value of neonicotinoid seed treatments across multiple trials in soybean, Glycine max L.; corn, Zea mays L.; cotton, Gossypium hirsutum L.; and sorghum, Sorghum bicolor L. production systems across the mid-southern region. Neonicotinoid seed treatments provided significant yield and economic increases when utilized the majority of the time. A second experiment was performed to determine the value of various insecticide classes when utilized in an overall systems approach when managing cotton insect pest in the Delta and Hills region of Mississippi. When all classes of insecticides were used in rotation, significant yield and economic benefits were observed in the Delta Region compared to treatment scenarios where some insecticide classes were omitted.

Cover crops are known to produce many conservation benefits. However, grower adoption remains low due to various issues and poor economic returns. This study was conducted to identify factors and management practices needed to integrate cover crops into Midsouth corn production systems. The effects of cover crop species, herbicide termination timing, and mechanical termination methods on the growth, grain yields, and economic returns of corn [Zea Mays (L.)] were investigated in Mississippi. The presence of living cover crops at planting stunted corn growth when they were not terminated by herbicides at least four weeks preplant. A legume cover crop reduced corn yield only when it was terminated at planting. The inclusion of a legume benefited the system compared to cereal rye. Cover crops produced neutral to negative crop yields, and all treatments reduced economic returns. Negative economic returns and production risks will likely limit cover crop adoption by corn growers.

Thesis (D. Min.)--Mid-America Baptist Theological Seminary, 2005. / Includes bibliographical references (leaves 138-151).