Effect of Soil-Applied Protoporphyrinogen Oxidase Inhibitor Herbicides on Soybean Seedling Disease

Seedling disease is one the most economically important diseases of soybean in the United States. It is commonly caused by Fusarium spp., Rhizoctonia solani, Pythium spp., and Phytophthora sojae, alone, or together as a disease complex. Fungicide seed treatments continue to provide the most consistent management of seedling diseases. Soil-applied protoporphyrinogen oxidase (PPO) inhibitor herbicides are used preemergence in soybean production to manage several broadleaf weeds. Applications of PPO-inhibitors can result in phytotoxic injury to soybean when environmental conditions are not favorable for soybean growth. These environmental conditions can favor seedling disease development as well. In this thesis, two studies were conducted to determine the effect of soil-applied PPO-inhibitors on soybean seedling disease development in Nebraska under field and controlled conditions. The first study assessed the effect of two PPO-inhibitors and a fungicide seed treatment on seedling disease and yield in 9 soybean fields in Nebraska. PPO-inhibitor injury occurred at 7 of 9 locations with inconsistent effects on seedling disease, where increases in root rot severity of 6.6–28.1% were observed at 5 of 9 locations, decreases of 4.7–10.9% at two locations, and no effect at three locations. None of these effects impacted yield at any of the locations. Fungicide seed treatment did not reduce root rot severity at any location; however, it increased yield at two locations. The second study investigated the effect of PPO-inhibitors on seedling disease caused by Fusarium solani under controlled conditions. Disease pressure was consistent throughout this study, with root rot severities ranging 32.1–38.9%. PPO-inhibitor injury occurred in all experiments with severities ranging 7.0–33.0%. Sulfentrazone alone increased root rot severity 9–12%. There was an effect of PPO-inhibitors on seedling disease development, although results were inconsistent, indicating a need for further research. PPO-inhibitors should continue to be used in part of an integrated weed management program and fungicide seed treatments should be used in fields that have a history of seedling disease. Advisor: Loren J. Giesle

Neonicotinoid seed treatments of soybean provide negligible benefits to US farmers

Neonicotinoids are the most widely used insecticides worldwide and are typically deployed as seed treatments (hereafter NST) in many grain and oilseed crops, including soybeans. However, there is a surprising dearth of information regarding NST effectiveness in increasing soybean seed yield, and most published data suggest weak, or inconsistent yield benefit. The US is the key soybean-producing nation worldwide and this work includes soybean yield data from 194 randomized and replicated field studies conducted specifically to evaluate the effect of NSTs on soybean seed yield at sites within 14 states from 2006 through 2017. Here we show that across the principal soybean-growing region of the country, there are negligible and management-specific yield benefits attributed to NSTs. Across the entire region, the maximum observed yield benefits due to fungicide (FST = fungicide seed treatment) + neonicotinoid use (FST + NST) reached 0.13 Mg/ha. Across the entire region, combinations of management practices affected the effectiveness of FST + N ST to increase yield but benefits were minimal ranging between 0.01 to 0.22 Mg/ha. Despite widespread use, this practice appears to have little benefit for most of soybean producers; across the entire region, a partial economic analysis further showed inconsistent evidence of a break-even cost of FST or FST + N ST. These results demonstrate that the current widespread prophylactic use of NST in the key soybean-producing areas of the US should be re-evaluated by producers and regulators alike

Neonicotinoid seed treatments of soybean provide negligible benefits to US farmers

Neonicotinoids are the most widely used insecticides worldwide and are typically deployed as seed treatments (hereafter NST) in many grain and oilseed crops, including soybeans. However, there is a surprising dearth of information regarding NST effectiveness in increasing soybean seed yield, and most published data suggest weak, or inconsistent yield benefit. The US is the key soybean-producing nation worldwide and this work includes soybean yield data from 194 randomized and replicated field studies conducted specifically to evaluate the effect of NSTs on soybean seed yield at sites within 14 states from 2006 through 2017. Here we show that across the principal soybean-growing region of the country, there are negligible and management-specific yield benefits attributed to NSTs. Across the entire region, the maximum observed yield benefits due to fungicide (FST = fungicide seed treatment) + neonicotinoid use (FST + NST) reached 0.13 Mg/ha. Across the entire region, combinations of management practices affected the effectiveness of FST + N ST to increase yield but benefits were minimal ranging between 0.01 to 0.22 Mg/ha. Despite widespread use, this practice appears to have little benefit for most of soybean producers; across the entire region, a partial economic analysis further showed inconsistent evidence of a break-even cost of FST or FST + N ST. These results demonstrate that the current widespread prophylactic use of NST in the key soybean-producing areas of the US should be re-evaluated by producers and regulators alike

Framing Social Justice: The Ties That Bind a Multinational Occupational Community

The notion of a frame is central to the conceptualisation of social justice and the grounding of social justice claims. Influential theories of social justice are typically grounded in national or cosmopolitan framings. Those entitled to raise claims of injustice are identified as citizens of states or the globe, respectively. The re-visioning of understandings of space and belonging, incumbent in the processes of globalisation, problematises static geographical framings. We offer an alternative lens and argue for the inclusion of sociological data in accounts of social justice to identify the relevant framing of the community of entitlement. Drawing on secondary analysis of a qualitative dataset, we explore the case of multinational seafarers caught at the intersection of competing appeals to nationality and commonality as an exemplar of transnational workers. And, argue that there are compelling grounds to treat this group of multinational seafarers as a community of entitlement

Noncomparabilities & Non Standard Logics

Many normative theories set forth in the welfare economics, distributive justice and cognate literatures posit noncomparabilities or incommensurabilities between magnitudes of various kinds. In some cases these gaps are predicated on metaphysical claims, in others upon epistemic claims, and in still others upon political-moral claims. I show that in all such cases they are best given formal expression in nonstandard logics that reject bivalence, excluded middle, or both. I do so by reference to an illustrative case study: a contradiction known to beset John Rawls\u27s selection and characterization of primary goods as the proper distribuendum in any distributively just society. The contradiction is avoided only by reformulating Rawls\u27s claims in a nonstandard form, which form happens also to cohere quite attractively with Rawls\u27s intuitive argumentation on behalf of his claims

Effect of Soil-Applied Protoporphyrinogen Oxidase Inhibitor Herbicides on Soybean Seedling Disease

Seedling disease is one the most economically important diseases of soybean in the United States. It is commonly caused by Fusarium spp., Rhizoctonia solani, Pythium spp., and Phytophthora sojae, alone, or together as a disease complex. Fungicide seed treatments continue to provide the most consistent management of seedling diseases. Soil-applied protoporphyrinogen oxidase (PPO) inhibitor herbicides are used preemergence in soybean production to manage several broadleaf weeds. Applications of PPO-inhibitors can result in phytotoxic injury to soybean when environmental conditions are not favorable for soybean growth. These environmental conditions can favor seedling disease development as well. In this thesis, two studies were conducted to determine the effect of soil-applied PPO-inhibitors on soybean seedling disease development in Nebraska under field and controlled conditions. The first study assessed the effect of two PPO-inhibitors and a fungicide seed treatment on seedling disease and yield in 9 soybean fields in Nebraska. PPO-inhibitor injury occurred at 7 of 9 locations with inconsistent effects on seedling disease, where increases in root rot severity of 6.6–28.1% were observed at 5 of 9 locations, decreases of 4.7–10.9% at two locations, and no effect at three locations. None of these effects impacted yield at any of the locations. Fungicide seed treatment did not reduce root rot severity at any location; however, it increased yield at two locations. The second study investigated the effect of PPO-inhibitors on seedling disease caused by Fusarium solani under controlled conditions. Disease pressure was consistent throughout this study, with root rot severities ranging 32.1–38.9%. PPO-inhibitor injury occurred in all experiments with severities ranging 7.0–33.0%. Sulfentrazone alone increased root rot severity 9–12%. There was an effect of PPO-inhibitors on seedling disease development, although results were inconsistent, indicating a need for further research. PPO-inhibitors should continue to be used in part of an integrated weed management program and fungicide seed treatments should be used in fields that have a history of seedling disease. Advisor: Loren J. Giesle

Evaluation of foliar‐applied post‐emergence corn–soybean herbicides on giant ragweed and waterhemp control in Wisconsin

Abstract Giant ragweed (Ambrosia trifida L.) and waterhemp (Amaranthus tuberculatus [Moq.] J.D.Sauer) are highly competitive and the most troublesome weeds in corn (Zea mays L.) and soybean (Glycine max Merr.) cropping systems in Wisconsin. Field experiments were conducted to evaluate the efficacy of multiple foliar‐applied POST‐emergence herbicides on giant ragweed at Janesville, WI (2020 and 2021), and on groups 2‐ and 9‐resistant waterhemp at Brooklyn, WI (2019 and 2020), respectively. Several herbicides from site of action groups 2, 4, 5, 6, 9, 10, 14, and 27 were evaluated. Herbicide treatments were applied when giant ragweed and waterhemp reached ~10 cm in height. Herbicide efficacy (0‐100% visual control) was evaluated 14 days after treatment (DAT). Group 2 herbicides provided poor (90% giant ragweed control. Certain herbicides from groups 4, 10, 14, and 27 provided the best control (74‐87%) of waterhemp, but no herbicide evaluated in this study provided = 90% waterhemp control. Weed management programs containing multiple effective herbicide sites of action PRE‐ and POST‐emergence accompanied by non‐chemical strategies are recommended to extend the spectrum of chemical control and reduce the risk of selection of further herbicide‐resistant biotypes for both giant ragweed and waterhemp in Wisconsin and beyond

Dose Proportionality of Treprostinil Sodium Administered by Continuous Subcutaneous and Intravenous Infusion

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97290/1/0091270007309708.pd