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In 2017, dicamba-resistant (DR) soybean was commercially available to farmers in the United States. In August and September of 2017, a survey of 312 farmers from 60 Nebraska soybeanproducing counties was conducted during extension field days or online. The objective of this survey was to understand farmers' adoption and perceptions regarding DR soybean technology in Nebraska. The survey contained 16 questions and was divided in three parts: (1) demographics, (2) dicamba application in DR soybean, and (3) dicamba off-target injury to sensitive soybean cultivars. According to the results, 20% of soybean hectares represented by the survey were planted to DR soybean in 2017, and this number would probably double in 2018. Sixty-five percent of survey respondents own a sprayer and apply their own herbicide programs. More than 90% of respondents who adopted DR soybean technology reported significant improvement in weed control. Nearly 60% of respondents used dicamba alone or glyphosate plus dicamba for POST weed control in DR soybean; the remaining 40% added an additional herbicide with an alternative site of action (SOA) to the POST application. All survey respondents used one of the approved dicamba formulations for application in DR soybean. Survey results indicated that late POST dicamba applications (after late June) were more likely to result in injury to non-DR soybean compared to early POST applications (e.g., May and early June) in 2017. According to respondents, off-target dicamba movement resulted both from applications in DR soybean and dicamba-based herbicides applied in corn. Although 51% of respondents noted dicamba injury on non-DR soybean, 7% of those who noted injury filed an official complaint with the Nebraska Department of Agriculture. Although DR soybean technology allowed farmers to achieve better weed control during 2017 than previous growing seasons, it is apparent that off-target movement and resistance management must be addressed to maintain the viability and effectiveness of the technology in the future.Nomenclature: dicamba; corn, Zea mays L.; soybean, Glycine max (L.) Merr.

Background Atrazine (ATZ) has been a key herbicide for annual weed control in corn, with both a soil and post-emergence vegetation application period. Although enhanced ATZ degradation in soil with a history of ATZ use has been reported, the extent and rate of degradation in the US Corn Belt is uncertain. We show that enhanced ATZ degradation exists across much of the country. Results Soils from 15 of 16 surveyed states had enhanced ATZ degradation. The average ATZ half-life was only 2.3 days in ATZ history soils, compared with an average 14.5 days in soils with no previous ATZ use, meaning that ATZ degrades an average 6 times faster in soils with previous ATZ use. Conclusion When ATZ is used for several years, enhanced degradation will undoubtedly change the way ATZ is used in agronomic crops and also its ultimate environmental fate. © 2017 Society of Chemical Industry.

California's ballot measures often reveal much about the broader U.S. policy environment. This is particularly true of the approval by the state's voters in November of Proposition 14, The California Stem Cell Research, Treatments, and Cures Initiative of 2020. Proposition 14 extends the 2004 ballot Proposition 71, which established the California Institute for Regenerative Medicine (CIRM) and authorized $3 billion in state-issued bonds for CIRM to fund stem cell and regenerative research and medicine (restricted to California). Proposition 14, which authorizes $5.5 billion over the next 10 years to continue CIRM's work, succeeded in part by informing voters of CIRM's successes and that its conflict-of-interest provisions are extremely strong. This state-level action is critical because, contrary to opponents' opinions, the overall policy environment for human stem cell research in the United States is in some ways worse now than when Proposition 71 passed. Since 2004, CIRM has funded groundbreaking work on immune disorders, cancer, spinal cord injury, diabetes, and more. The result has been more than 90 stem cell–related clinical trials (directly or indirectly supported by CIRM), almost 3000 scientific papers, and contributions to two cancer therapies approved by the U.S. Food and Drug Administration. The lives of many patients have improved because of CIRM. Notably, many CIRM-funded clinical trials rely on human embryonic or fetal stem cells, whereas the federal government currently does not fund any clinical trials using these types of cells. Proposition 71 was motivated largely in response to restrictions on human embryonic stem cell research in the United States in 2004. However, although research was limited to a small number of human embryonic stem cell lines, there was no formal ban on federal funding of research on such stem cells. In addition, in 2004 there were no restrictions on federal funding of human fetal stem cell and tissue research; however, there is now near-complete blockage of federal funding for such research. And federal funding for human embryonic stem cell research is again at risk. On 4 September 2020, 22 Republican senators and 72 Republican House members wrote to President Trump requesting an end to all federal funding of human embryonic stem cell research. Could President Trump impose a ban that would be difficult to revoke? Or, could Republican senators manufacture a ban by legislative maneuvering on a budget reconciliation vote, which requires 60% support? Such maneuvering created the effectively permanent 1995 Dickey-Wicker amendment, which prohibits federal funding of any research in which human embryos are created or destroyed. Dickey-Wicker has limited research on in vitro fertilization methods and stalled progress on understanding early human development. It has not solved the problem of the many, perhaps 1 million frozen embryos in the United States that will not be used for in vitro fertilization and will be destroyed without benefit if not used for research. Vital long-term research is greatly harmed by the U.S. policy environment, with the likely outcome that many young scientists will avoid research using human embryonic stem cells and human fetal tissue. Restrictions on valuable, ethical research appear particularly fool-hardy during a deadly pandemic. Research on viruses such as HIV and SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) can benefit greatly from work using mice that utilize human fetal stem cells and tissues to generate a human-like immune system. These mice allow evaluation of a human immune system in the contexts of infection mechanisms, generation of immunity, and drug response. These studies can be supported with Proposition 14 funds in California, but not with federal funds. It is crucial for the incoming Biden administration to evaluate the need for federal funding in these important areas with high-quality scientific input and evidence. California's vote on Proposition 14 should also help the rest of the country appreciate the need to increase investments in biomedical research at the U.S. National Institutes of Health and other federal agencies. Current biomedical research expenditures amount to only a tiny fraction of the costs of disease, so an objective evaluation of appropriately increased research funding relative to disease costs is warranted. Once again, California is showing the way.

Fire exclusion in the United States over the last century has had major impacts on forest ecosystems and landscapes. Out of a desire to reverse or mitigate the impacts of fire exclusion, some managers conduct prescribed fires meant to mimic the historic ecological role of fire and restore ecosystem properties. In the Southern Appalachians, fire exclusion in pine- and oak-dominated xeric ridge forests has allowed fire-sensitive hardwood species to establish, filling in the canopy and creating shady, moist conditions that are unfavorable for reproduction of fire-dependent pines and oaks. Managers of natural areas use prescribed fire to restore pine and oak dominance, promote pine and oak regeneration, and reduce stand densities. Here, we use multivariate analysis of monitoring data collected before and after 21 fires over 16 years in fire-suppressed xeric pine-oak forests in the Great Smoky Mountains National Park to assess how community composition and structure change after prescribed fire, to what degree changes after fire persist over time, and how the impacts of prescribed fire vary with fire severity and site environment. Fire consistently reduces stand density and shifts plots towards lower shrub cover and higher herbaceous cover. On the other hand, compositional shifts, i.e. changes in relative abundances of species, were highly variable in both magnitude and direction. Fire severity, measured as total fuel reduction and litter and duff reduction, was important for predicting the magnitude of change after fire. The magnitude of fire effects also varied with elevation, likely reflecting variation in local moisture conditions. Our results indicate that while fires do reduce stand density, they have not yet been successful in consistently restoring pine and oak dominance in the canopy. Restoring pine- and oak-dominance in xeric ridge forests in the Southern Appalachians will thus require extended management focus with flexible, adaptive, long-term planning and continued monitoring and research.

NE01481' (Reg. No. CV-1061, PI 659689) hard red winter wheat (Triticum aestivum L.) was developed cooperatively by the Nebraska Agricultural Experiment Station and the USDA-ARS and released in April 2010. NE01481 will be marketed as Husker Genetics brand McGill. In addition to superior agronomic performance, Nebraska wheat growers would like to have increased resistance to Wheat soilborne mosaic virus. NE01481 was selected from the cross NE92458/'Ike' that was made in 1995. The pedigree of NE92458 is OK83201/'Redland' and the pedigree of OK83201, an experimental line developed by Oklahoma State University is 'Vona'//'Chisholm'/'Plainsman V'. NE01481 was selected with the bulk- breeding method as an F 3:4 line in 1999, and in 2001 it was assigned experimental line number NE01481. NE01481 was released because of its superior grain yield in rainfed wheat production systems in southeastern, south central, and southwestern Nebraska and that it is the fi rst modern release from our program with resistance to Wheat soilborne mosaic virus.

Water for irrigation is a major constraint in the Great Plains, and it is expected that the proportion of irrigated crop land to grow irrigated wheat (Triticum aestivum L.), which requires less water than other crops, will increase to conserve irrigation water. ‘NI04421’ (Reg. No. CV-1064, PI 659690) hard red winter wheat (Triticum aestivum L.) was developed cooperatively by the Nebraska Agricultural Experiment Station and the USDA-ARS and released in 2010 by the developing institutions and the Wyoming Agricultural Experiment Station. NI04421 was released primarily for its superior performance under irrigation and rainfed conditions in western Nebraska and eastern Wyoming. NI04421 was selected from the cross NE96644/Wahoo (sib) where the pedigree of NE96644 is ‘Odesskaya P’/‘Cody’//‘Pavon 76’/*3 ‘Scout 66’. The cross was made in the spring of 1998. NI04421 was selected using a modifi ed bulk-breeding method as an F 3:4 line (F 3 -derived line in the F 4 generation) in 2002, and in 2004 was assigned experimental line number NI04421. After extensive testing, it was released in July 2010.

We used pre- and post-burn fire effects data from six prescribed burns to examine post-burn threshold effects of stand structure (understory density, overstory density, shrub cover, duff depth, and total fuel load) on the regeneration of yellow pine (Pinus subgenus Diploxylon) seedlings and cover of herbaceous vegetation in six prescribed-fire management units located within western Great Smoky Mountains National Park (GSMNP) in east Tennessee, USA. We also evaluated the utility of the Keetch–Byram Drought Index (KBDI) as a predictor of post-burn stand and fuel conditions by comparing post-burn stand variables for different ranges of KBDI (23–78; more wet, and 328–368; more dry). We found that yellow pine seedlings were effectively absent in post-burn forests until overstory density was reduced over 40%, understory density was reduced over 80%, and post-burn shrub cover was 10% or less. We also observed that a reduction in total fuels of 60% and a post-burn duff layer depth of less than four cm were required for successful regeneration of yellow pine. Total herbaceous species cover exhibited near identical responses with increased cover following an 80% reduction in understory density and a post-burn duff depth of less than 4 cm. We observed strong positive relationships between high KBDI values and burn severity, changes in forest structure, reductions in fuels, and post-burn yellow pine reproduction. We observed continuous recruitment of yellow pine seedlings 5 years after fire in high KBDI burns while low KBDI burns showed little change in yellow pine density through time. An intense outbreak of the southern pine beetle (SPB; Dendroctonus frontalis) occurred within 2 years of our high KBDI burns and reduced shading resulting from overstory mortality likely enhanced the survival of yellow pine seedlings. The results of this study provide targets for the application of prescribed fire to restore yellow pine in the southern Appalachians. Continued research and monitoring will help determine how prescribed fire can best be applied in combination with other disturbance agents such as SPB to perpetuate yellow pine forests.

NH03614 CL' (Reg. No. CV-1051, PI 653833) hard red winter wheat (Triticum aestivum L.) was developed cooperatively by the Nebraska Agricultural Experiment Station and the USDA-ARS and released in 2008 by the developing institutions and the South Dakota Agricultural Experiment Station and the Wyoming Agricultural Experiment Station. In addition to researchers at the releasing institutions, USDA-ARS researchers at Manhattan, KS and St. Paul, MN participated in the development of NH03614 CL. NH03614 CL was selected from the cross 'Wesley' sib//'Millennium' sib/'Above' sib that was made in the spring of 1997 to develop new herbicide-tolerant cultivars. NH03614 CL was selected using the bulk breeding method as an F 3:4 line (F 3 -derived line in the F 4 generation) in 2001, and in 2003 was assigned experimental line number NH03164. NH03614 CL was released primarily for its herbicide tolerance to imadazolinone compounds which control many previously diffi cult-to-control weeds in wheat production systems, and for its superior adaptation to rainfed wheat production systems in Nebraska, Wyoming, South Dakota, and counties in adjacent states.

In diverse growing environments, cultivar blends of hard winter wheat (Triticum aestivum L.) are considered as an option over pure cultivars for maintaining grain yield and reducing risk to producers. The objectives of this research were to evaluate the grain yield between blends and their component cultivars over several locations in Nebraska and to compare blend grain yield stability. Two separate experiments of six three-cultivar blends and their component cultivars tested in a total of 30 environments and three two-cultivar blends and their component cultivars tested in a total of 20 environments were grown in replicated randomized block designs. All component cultivars and cultivar blends (referred to as lines, hereafter) were evaluated for mean grain yield performance and stability. 'Pronghorn'-'Goodstreak'-'Buckskin' was the sole cultivar blend that significantly increased grain yield when compared with the average of its component cultivars. The grain yield advantage for the mean average cultivar blends varied from 2.2% lower to 1.9% higher with overall advantage of 0.4% yield increase for all the nine cultivar blends. Cultivar blends of 'Millennium'-'Wesley'-'Wahoo', Millennium-'Halt'-Wahoo, and Millennium-'Alliance'-Wahoo were the most stable lines using regression estimates for stability. When compared with the average of component cultivars, cultivar blends were more stable over different environments with little or no reduction in grain yield.

In upland forests of the Southern US, management is increasingly focussed on the restoration and maintenance of resilient structures and species compositions, with prescribed burning being the primary tool used to achieve these goals and objectives. In this study, we utilised an extensive dataset comprising 91 burn units and 210 plots across 13 National Park Service lands to examine the relationships between the probability of stem mortality (P(m)) 2 years after prescribed fire and stem size and direct fire effects for 10 common deciduous broadleaved species. Post-fire stem mortality ranged from 6.9% for Quercus alba to 58.9% for Sassafras albidum. The probability of stem mortality was positively associated with maximum bole char height (CHAR) and inversely related to diameter at breast height (DBH) for all 10 deciduous broadleaved species. Model goodness-of-fit varied, with the poorest fit generally associated with fire-tolerant species and best fit generally associated with fire sensitive species. The information presented contributes to our understanding of post-fire stem mortality and may contribute to the development of fire-related stem mortality models following prescribed burning for eastern tree species. Models should be validated with independent datasets across upland forests types to test for spatial relationships before widespread application.

Sweet sorghum [SS; Sorghum bicolor (L.) Moench] is a potential biofuel crop for the Great Plains. Sweet sorghum was compared with corn [ Zea mays (L.)] and grain sorghum for potential ethanol yield, energy use effi ciency, and greenhouse gas (GHG) emis-sions at seven dryland site-years in Nebraska. Seasonal rainfall ranged from approximately 340 to 660 mm. Soils were deep with medium texture at all site-years. Th e eff ects of seeding rate, N rate, and cultivar on SS performance were evaluated. Sweet sorghum sugar yield was not aff ected by seeding rate and N application at six of seven site-years, but yield was increased by 19% at one site-year. Calculated ethanol yield and net energy yield were 33 and 21% more, respectively, with the grain crops compar ed with SS, but mean net energy yield of an earlier-maturing SS cultivar was comparable with the grain crops. Th e mean ratio of energy produced in ethanol per total energy invested was 23% less for grain crops compared with SS. Mean life cycle GHG emis-sions were 53% and 66 to 69% less compared with gasoline for SS and grain crops, respectively. Very effi cient use of the ethanol coproducts was assumed for the grain crops while SS bagasse was assumed to be returned to the fi eld. At least one SS cultivar is competitive with grain crops for some biofuel criteria, but SS is not competitive with grain crops for total or net liquid transpor-tation fuel produced per hectare.

Although glyphosate controls many plant species, certain broadleaf weeds in Nebraska's cropping systems exhibit various levels of tolerance to the labeled rates of this herbicide, including ivyleaf morningglory, Venice mallow, yellow sweetclover, common lambsquarters, velvetleaf, kochia, Russian thistle, and field bindweed. Therefore, two field studies were conducted in 2004 and 2005 at Concord and North Platte, NE, to evaluate performance of (1) seven preemergence (PRE) herbicides and (2) glyphosate tank mixes applied postemergence (POST) at three application times for control of eight weed species that are perceived as problem weeds in glyphosate-resistant soybean in Nebraska. The PRE herbicides, including sulfentrazone plus chlorimuron, pendimethalin plus imazethapyr, imazaquin, and pendimethalin plus imazethapyr plus imazaquin provided more than 85% control of most weed species tested in this study 28 d after treatment (DAT). However, sulfentrazone plus chlorimuron and pendimethalin plus imazethapyr plus imazaquin were the only PRE treatments that provided more than 80% control of most weed species 60 DAT. In the POST glyphosate tank-mix study, the level of weed control was significantly affected by the timing of herbicide application; control generally decreased as weed height increased. In general, glyphosate tank mixes applied at the first two application times (early or mid-POST) with half label rates of lactofen, imazamox, imazethapyr, fomesafen, imazaquin, or acifluorfen, provided more than 80% control of all species that were 20 to 30 cm tall except ivyleaf morningglory, Venice mallow, yellow sweetclover, and field bindweed. Glyphosate tank mixes applied late POST with lactofen, imazethapyr, or imazaquin provided more than 70% control of common lambsquarters, velvetleaf, kochia, and Russian thistle that were 30 to 50 cm tall. Overall, glyphosate tank mixes with half label rates of chlorimuron or acifluorfen were the best treatments; they provided more than 80% control of all the studied weed species when applied at early growth stages. Results of this study suggested that mixing glyphosate with other POST broadleaf herbicides, or utilizing soil-applied herbicides after crop planting helped effectively control most problematic weeds in glyphosate-resistant soybean in Nebraska.

Camelot ' (Reg. No. CV-1036, PI 653832) hard red winter wheat (Triticum aestivum L.) was developed cooperatively by the Nebraska Agricultural Experiment Station and the USDA-ARS and released in 2008. In addition to researchers at the releasing institutions, USDA-ARS researchers at Manhattan, KS, and St. Paul, MN, participated in the development of Camelot. Camelot was selected from the cross KS91H184/'Arlin' Sib//KS91HW29/3/NE91631/4/VBF0168 that was made in 1995. Camelot was selected as an F 3:4 line (F 3 -derived line in the F 4 generation) in 1999, and in 2001 it was assigned experimental line number NE01604. Camelot was released because of its superior grain yield performance, disease resistance, and end-use quality under nonirrigated production in Nebraska and adjacent states.

Field experiments were conducted at five sites in Nebraska in 2000 and 2001 to determine the effect of planting depth and isoxaflutole rate on the response of an isoxaflutole-sensitive corn hybrid, ‘Pioneer 33-G’ across variable environments. Corn was planted at depths of 2.5 and 5.0 cm, and isoxaflutole was applied PRE at the recommended (1×) and twice the recommended (2×) rate. The effects of planting depth and herbicide rate on injury varied considerably across site–years. When injury was evident, it was generally greater at the high rate of isoxaflutole (2×) and at the shallow planting depth (2.5 cm). In most site–years, corn recovered from early season injury, and yields were not reduced, except at Scottsbluff, NE, and North Platte, NE, where soils were lower in organic matter and higher in pH. Isoxaflutole rates should be carefully selected for soils with low organic matter and high pH. Nomenclature: Isoxaflutole, corn, Zea mays L

Field experiments were conducted to evaluate the effect of five spray-nozzle types and three drift-control adjuvants (DCA) on glyphosate spray drift. The extended-range (XR) flat-fan nozzle at 280 kPa was used as the standard comparison. DCAs were evaluated for drift reduction with the use of the XR and air-induction (AI) nozzles. Wind speed ranged from 1.3 to 9.4 m/s (3 to 21 mph). Lethal drift (DL) and injury drift (DI) were determined by downwind visual observation of grain sorghum response. Drift distances were measured from the spray swath edge. The Turbo FloodJet and AI nozzles reduced DLdistance by 34%. All four drift-reducing (DR) nozzles reduced DIdistance by 22 to 32%. Reducing the pressure of the XR flat-fan nozzle from 280 to 140 kPa did not reduce DLor DIdistance. When applied through AI nozzles, each DCA increased droplet volume diameter, one DCA reduced DIdistance and none reduced DLdistance when applied through XR tips. The DCAs did not affect DLor DIdistance.

Thirteen hard red winter wheat cultivars were evaluated for their ability to suppress summer annual weeds in grain production systems near North Platte, NE, from 1993 through 1997. ‘Turkey’, a 125-yr-old landrace selection, suppressed both broadleaf and grass weeds more than other cultivars. Some relatively new cultivars, such as ‘Arapahoe’, ‘Jules’, ‘Pronghorn’, and ‘Vista’ suppressed summer annual grasses almost as well as Turkey. Total weed density was negatively correlated with number of winter wheat stems/m2, mature winter wheat height, and lodging. Weed density after wheat harvest was positively correlated with delay in winter wheat seeding date and was negatively correlated with precipitation 0 to 30 d after winter wheat seeding, during tillering, tillering to boot stage, and heading to maturity stage. Mean air temperature 0 to 30 d after wheat seeding was positively correlated with weed density. In the spring, weed density was positively correlated with temperatures during the tillering stage, tillering to boot stage, and heading to maturity stage. Stinkgrass and witchgrass densities were positively correlated with severity of wheat leaf rust. The highest grain-producing cultivars included three medium height cultivars ‘Alliance’, Arapahoe, and ‘Niobrara’. Alliance wheat produced 53% more grain than Turkey, and the other two produced 43% more grain.

A tractor-mounted, air-pressurized, herbicide application system was designed and constructed for use in weed management research on cropland, pastures, and rangeland. The spray system was designed to minimize wind-induced spray pattern distortion, to enable accurate application of multiple treatments, to withstand the stresses of use on uneven and rough terrain, to apply herbicide treatments reliably, to be easy to transport, to be constructed with readily available spray system components, and to enable quick diagnosis and resolution of operational problems. The spray system has a total shield frame length of 5.2 m. The shielded frame comprises three sections. The two outside sections are connected to the center section by hinges so that they can be folded up and over the center section for transport or storage. Four spray booms are mounted inside the shield with a 50-cm distance between nozzles. Herbicides are usually applied with the bottom of the shield placed 20 cm above the soil or plant surface. T...

Herbicide-resistant crops like glyphosate resistant (GR) soybean [Glycine max (L.) Merr.] are gaining acceptance in U.S. cropping systems. Comparisons from cultivar performance trials suggest a yield suppression may exist with GR soybean. Yield suppressions may result from either cultivar genetic differentials, the GR genelgene insertion process, or glyphosate. Grain yield of GR is probably not affected by glyphosate, Yield suppression due to the GR gene or its insertion process (GR effect) has not been reported. We conducted a field experiment at four Nebraska locations in 2 yr to evaluate the GR effect on soybean yield. Five backcross-derived pairs of GR and non-GR soybean sister lines were compared along with three high-yield, nonherbicide-resistant cultivars and five other herbicide-resistant cultivars. Glyphosate resistant sister lines yielded 5% (200 kg ha -1 ) less than the non-GR sisters (GR effect). Seed weight of the non-GR sisters was greater than that of the GR sisters (in 1999) and the non-GR sister lines were 20 mm shorter than the GR sisters. Other variables monitored were similar between the two cultivar groups. The high-yield, nonherbicide-resistant cultivars included for comparison yielded 5% more than the non-GR sisters and 10% more than the GR sisters.

Glyphosate (N-(phosphonomethyl) glycine)-resistant (GR) soybean [Glycine max (L.) Merr.] technology is gaining acceptance in U.S. cropping systems, yet potential yield suppression from either cultivar genetic differentials, the GR gene/gene insertion process, or glyphosate is a concern. Other work shows that the GR gene/gene insertion process may suppress soybean yield. No one has reported the effects of glyphosate on a diverse group of commercially available GR soybean cultivars, In this study we evaluated one of the potential sources of GR yield suppression-the effect of glyphosate on yield, growth, and development of GR cultivars. Field experiments were conducted at four Nebraska locations with12 GR cultivars in 1998 and 13 GR cultivars in 1999. Soybean response to glyphosate, ammonium sulfate (AMS), and water application at 21 and 42 d after soybean emergence was compared with control plots treated with AMS and water in 1998. An additional control, water alone, was added in 1999. Grain yield among cultivars differed as expected with a range of 3.44 to 3.96 Mg ha -1 in the 2-yr averages, Glyphosate did not affect the majority of the soybean growth and development characteristics measured. Grain yield of GR soybean was not affected by glyphosate at any location or when averaged over locations. Two-year average grain yield of cultivars treated with glyphosate, AMS, and water was 3.74 Mg ha 1 ; this was not different from 3.79 Mg ha -1 with AMS and water treatment.

Ridge-till is an integrated weed management system that involves the physical movement of soil containing weed seeds away from the row with ridge-clearing equipment on the planter. Corn, grain sorghum, and soybean are the major crops planted using the ridge-till system. Weeds can be controlled with cultivation, competitive row crops, and herbicides. Weeds have adapted to the system but have been controlled through alternative management. Through modernization of equipment and herbicides, ridge-till has become an economic crop production practice. Integrating cultivation and herbicides controls a broader spectrum of weeds than cultivation or herbicides alone.

Fungicides, when applied in the most effective way, can greatly improve the efficacy of the fungicide, reduce the risk of resistance, and potentially increase yields or preserve crops. When making fungicide applications, there are several things that must be considered. Most sprayers use hydraulic nozzles with pressure against an orifice. The applicator must consider which type of nozzle to use (both orifice size and nozzle type) as well as operating pressure.

We conducted research to determine if soybeans can be grown successfully in a no-till environment, in the semi-arid areas of the central Great Plains near North Platte, NE. Soybeans planted no-till into winter wheat stubble that was sprayed with glyphosate yielded more than when planted into soil that was rototilled in a winter wheat-soybean-fallow rotation. However, grain yield averaged only 420 kg ha-1during 1975, 1976, and 1977. No-till soybean grown in a winter wheat-grain sorghum-soybean rotation during 1982 through 1985 yielded an average of 1370 kg ha-1. Low yields were associated with lack of precipitation during the fallow period after winter wheat harvest or grain sorghum harvest and during the soybean pod elongation and filling period. Several herbicides gave excellent weed control in soybeans when applied either after wheat harvest, early preplant, or at planting time. None of the herbicides persisted long enough to reduce grain yields of winter wheat planted into the soybean residue. With present production costs these nonirrigated rotations are not economical in the semi-arid region of the central Great Plains of the United States.

This literature review is designed to develop guidelines needed for the use of a sphenopalatine ganglion block versus a stellate ganglion block to reduce atypical facial pain. We have reviewed the basic anatomy of both ganglia and the physiological responses usually associated with each, and have given an opinion on appropriate use of these therapeutic modalities.

Pollinators serve critical roles for the functioning of terrestrial ecosystems, and have an estimated annual value of over $150 billion for global agriculture. Mounting evidence from agricultural systems reveals that pollinators are declining in many regions of the world, and with a lack of information on whether pollinator communities in natural systems are following similar trends, identifying factors which support pollinator visitation and services are important for ameliorating the effects of the current global pollinator crisis. We investigated how fire affects resource structure and how that variation influences floral pollinator communities by comparing burn versus control treatments in a southeastern USA old-field system. We hypothesized and found a positive relationship between fire and plant density of a native forb, Verbesina alternifolia, as well as a significant difference in floral visitation of V. alternifolia between burn and control treatments. V. alternifolia density was 44% greater and floral visitation was 54% greater in burned treatments relative to control sites. When the density of V. alternifolia was experimentally reduced in the burn sites to equivalent densities observed in control sites, floral visitation in burned sites declined to rates found in control sites. Our results indicate that plant density is a proximal mechanism by which an imposed fire regime can indirectly impact floral visitation, suggesting its usefulness as a tool for management of pollination services. Although concerns surround the negative impacts of management, indirect positive effects may provide an important direction to explore for managing future ecological and conservation issues. Studies examining the interaction among resource concentration, plant apparency, and how fire affects the evolutionary consequences of altered patterns of floral visitation are overdue.

Many factors, including adjuvants, pesticide formulations, and nozzle tips, affect spray droplet size. It is important to understand these factors as spray droplet size affects both drift and efficacy of pesticides, which is a main concern with pesticide application. A laser particle analyzer was used to determine the spray droplet size and distributions of a range of formulations sprayed through several types of nozzle tips. Nozzles included were extended range flat fan sizes 11003 and 11005 (Spraying Systems XR), air induction flat fan sizes 11005 and 11004 (AI), air induction extended range flat fan size 11005 (AIXR), preorifice flat fan size 11005 (TT), and a second preorifice flat fan size 2.5 (TF). Several deposition/retention adjuvants were studied, including Array, Interlock, In-Place, and Thrust. Another study looked at diflufenzopyr + dicamba (Status, BASF) in combination with several adjuvants. Also, three fungicides were evaluated at differing spray volumes. Results indicated that the droplet size of some nozzle tips is more affected than others by changes in the contents of the spray solution.