Impact of the Timing and Use of an Insecticide on Arthropods in Cover-Crop-Corn Systems

Cover crops provide a habitat for pests and beneficial arthropods. Unexpected pest pressure in a cover-crop-to-corn system can occur and result in increased use of insecticides. Eight site-years of on-farm field studies were conducted in 2019, 2020, and 2021. The objective of the study was to evaluate the impact of insecticide timing relative to cover-crop termination on arthropod activity in a cover-crop-to-corn system. The treatments consisted of (i) glyphosate to terminate the cover crop, (ii) glyphosate and pyrethroid tank mix to terminate the cover crop, and (iii) glyphosate to terminate the cover crop and pyrethroid application 25 days after the termination. Arthropod activity was measured with pitfall traps before and at each treatment application. A total of 33,316 arthropods were collected. Total arthropods, Collembola, and Aphididae were the only taxa reduced with an insecticide application. The other arthropod taxa were mainly influenced by the sampling period. No significant pest pressure occurred at any site-year. Insecticide applications are not generally needed in a cover-crop-to-corn system. Scouting for pests and applying strategies only when necessary is crucial to conserve potentially beneficial arthropods in the system

Field Evaluation of Commercially Available Small Unmanned Aircraft Crop Spray Systems

Agricultural research and development on small unmanned aircraft systems (UAS) has been directed toward UAS enabled sensing to detect features of interest. While compelling, there is an immediate need to increase the breadth and depth of UAS-based research, to move beyond sensing, and explore active intervention in agricultural production systems. This paper is focused on the concept of crop protection through ultra-precise, unmanned aerial application systems, and seeks to initiate research discussion in this important area of opportunity. Toward this end, two different, commercially available, small Unmanned Aerial Application Systems (sUAAS - defined as less than 55 lbs. maximum take-off weight) were evaluated for operational techniques and application system efficacy under dynamic field conditions. The performance of the factory supplied spray equipment systems are documented using traditional aerial spray testing methods that have been modified for UAS enabled application systems, referred to as small Unmanned Aerial Application Systems (sUAAS). Results from initial testing protocols indicate that the factory supplied systems are quite different in design and implementation, with spray test results that reflect this difference in design, in both deposition and spray swath. Further, it is apparent that with the advent of unmanned aerial application systems, and the unique characteristics of the integrated aircraft and application systems, there is a very real need for the development of standardized sUAAS testing procedures

Over-summering ecology of the wheat curl mite (Aceria tosichella keifer)

The wheat-mite-virus complex is a consistent and significant threat to winter wheat production in the western Great Plains. This complex consists of three viruses (Wheat streak mosaic virus, Triticum mosaic virus, and Wheat mosaic virus that are transmitted by the wheat curl mite (Aceria tosichella Keifer). Yield impacts from this complex are typically associated with the presence of volunteer wheat that emerges prior to harvest as a result of hail occurring during the heading stages of wheat in early summer. Historical literature on pre-harvest germination has been primarily focused on accelerating breeding programs; however, critical gaps in knowledge exist on pre-harvest germination when evaluating risk for the wheat-mite-virus complex. A study was designed to evaluate pre-harvest germination potential of winter wheat by collecting heads at 7-9 day intervals beginning at the water-ripe stage until wheat harvest. In addition, risk categories were established based on the speed of germination because field germination will be limited by moisture availability. A second study was conducted in the field to evaluate the impact of environmental conditions on pre-harvest germination. Results indicate that risk for pre-harvest germination begins at the late milk stage with increasingly greater risk for germination up to harvest. In addition, risk for germination is highly dependent on available moisture following hail events. Historical observations, as well as anecdotal evidence indicate that other hosts besides wheat can support WCM during the over-summering period; however, the risk of these hosts to fall planted wheat is poorly understood. Greenhouse reproductive studies, a field study on mite movement and virus impact, and a weed survey were conducted to evaluate the risk potential of over-summering hosts. Results showed that barnyard grass is a high-risk over-summering host for the wheat-mite-virus complex; however, its frequency is relatively low across the central Great Plains. Green foxtail was comparatively a lower risk host, but it was found in higher frequencies in the weed survey. Foxtail millet, another summer annual, showed significant mite movement under field conditions; however, virus impact was minimal. In addition, greenhouse studies were a good predictor of field potential of all of the over-summering hosts with the exception of foxtail millet. The studies presented in this document provide critical information to better understanding the over-summering ecology and risk of the wheat- mite-virus complex

Over-summering ecology of the wheat curl mite (Aceria tosichella keifer)

The wheat-mite-virus complex is a consistent and significant threat to winter wheat production in the western Great Plains. This complex consists of three viruses (Wheat streak mosaic virus, Triticum mosaic virus, and Wheat mosaic virus that are transmitted by the wheat curl mite (Aceria tosichella Keifer). Yield impacts from this complex are typically associated with the presence of volunteer wheat that emerges prior to harvest as a result of hail occurring during the heading stages of wheat in early summer. Historical literature on pre-harvest germination has been primarily focused on accelerating breeding programs; however, critical gaps in knowledge exist on pre-harvest germination when evaluating risk for the wheat-mite-virus complex. A study was designed to evaluate pre-harvest germination potential of winter wheat by collecting heads at 7-9 day intervals beginning at the water-ripe stage until wheat harvest. In addition, risk categories were established based on the speed of germination because field germination will be limited by moisture availability. A second study was conducted in the field to evaluate the impact of environmental conditions on pre-harvest germination. Results indicate that risk for pre-harvest germination begins at the late milk stage with increasingly greater risk for germination up to harvest. In addition, risk for germination is highly dependent on available moisture following hail events. Historical observations, as well as anecdotal evidence indicate that other hosts besides wheat can support WCM during the over-summering period; however, the risk of these hosts to fall planted wheat is poorly understood. Greenhouse reproductive studies, a field study on mite movement and virus impact, and a weed survey were conducted to evaluate the risk potential of over-summering hosts. Results showed that barnyard grass is a high-risk over-summering host for the wheat-mite-virus complex; however, its frequency is relatively low across the central Great Plains. Green foxtail was comparatively a lower risk host, but it was found in higher frequencies in the weed survey. Foxtail millet, another summer annual, showed significant mite movement under field conditions; however, virus impact was minimal. In addition, greenhouse studies were a good predictor of field potential of all of the over-summering hosts with the exception of foxtail millet. The studies presented in this document provide critical information to better understanding the over-summering ecology and risk of the wheat- mite-virus complex

Soybean gall midge

"This publication is partially funded by a USDA NIFA grant in the Crop Protection and Pest Management Program.""Soybean gall midge (Resseliella maxima) is a newly described insect species that attacks soybean creating severe economic damage. Isolated sightings were first reported in Nebraska during 2011. Soybean gall midge is currently established in 114 counties throughout South Dakota, Minnesota, Iowa, Nebraska and Missouri (Figure 1)."--First page.Written by Alyssa L. Lucas (GRA, Division of Plant Sciences, University of Missouri), Justin McMechan (Assistant Professor, Entomology Department, University of Nebraska-Lincoln), Kevin B. Rice (Assistant Professor, Division of Plant Sciences, University of Missouri)New 4/202

Field Evaluation of Commercially Available Small Unmanned Aircraft Crop Spray Systems

Agricultural research and development on small unmanned aircraft systems (UAS) has been directed toward UAS enabled sensing to detect features of interest. While compelling, there is an immediate need to increase the breadth and depth of UAS-based research, to move beyond sensing, and explore active intervention in agricultural production systems. This paper is focused on the concept of crop protection through ultra-precise, unmanned aerial application systems, and seeks to initiate research discussion in this important area of opportunity. Toward this end, two different, commercially available, small Unmanned Aerial Application Systems (sUAAS - defined as less than 55 lbs. maximum take-off weight) were evaluated for operational techniques and application system efficacy under dynamic field conditions. The performance of the factory supplied spray equipment systems are documented using traditional aerial spray testing methods that have been modified for UAS enabled application systems, referred to as small Unmanned Aerial Application Systems (sUAAS). Results from initial testing protocols indicate that the factory supplied systems are quite different in design and implementation, with spray test results that reflect this difference in design, in both deposition and spray swath. Further, it is apparent that with the advent of unmanned aerial application systems, and the unique characteristics of the integrated aircraft and application systems, there is a very real need for the development of standardized sUAAS testing procedures

A perspective on changes across the U.S. Corn Belt

Corn (Zea mays L.) has long been a staple crop of the Corn Belt of the U.S., which today extends latitudinally from central Nebraska to central Ohio and longitudinally from northeast Kansas to the eastern Dakotas and western Minnesota. However, the production of corn in the Corn Belt has been transformed in both magnitude and spatial extent since the 1960s. Previous research has shown that there has been an overall increase in the number of acres planted to corn across the Corn Belt (e.g. Johnston 2014, Lark et al 2015), with a pronounced increase in the eastern Dakotas and modest increases across the historical Corn Belt, which includes most of the states of Illinois, Indiana, and Iowa (i.e. the ‘I’ states). Much of the intensification across the Dakotas can be attributed to the conversion of grasslands and small grains croplands (e.g. wheat and barley; Lin et al 2016; Laingen 2017, Wimberly et al 2017) for corn and soybean (Glycine max L.). Some of this change can be attributed to government programs (Laingen 2011) and to the substantial increase for corn ethanol in areas with traditionally lower corn yields (Murphy et al 2011). Recent research also highlights a north and westward spatial shift in the Corn Belt (Hart and Lindberg 2014; Laingen 2017, Auch et al 2018) such that the geographic mean of the Corn Belt has shifted over 200 km northwest since the 1950s (Laingen 2017). In this paper, we build on these previous studies by presenting evidence of two key points: 1) The relative dominance of corn production of the traditional Corn Belt has been diminished, and 2) The crop reporting districts with the highest corn production have also started to shift spatially, partly from increased acreage outside the traditional Corn Belt and partly from spatial shifts in the districts with the highest corn yield trends

Author response for A Perspective on Changes Across the U.S. Corn Belt

Corn (Zea mays L.) has long been a staple crop of the Corn Belt of the U.S., which today extends latitudinally from central Nebraska to central Ohio and longitudinally from northeast Kansas to the eastern Dakotas and western Minnesota. However, the production of corn in the Corn Belt has been transformed in both magnitude and spatial extent since the 1960s. Previous research has shown that there has been an overall increase in the number of acres planted to corn across the Corn Belt (e.g. Johnston 2014, Lark et al 2015), with a pronounced increase in the eastern Dakotas and modest increases across the historical Corn Belt, which includes most of the states of Illinois, Indiana, and Iowa (i.e. the ‘I’ states). Much of the intensification across the Dakotas can be attributed to the conversion of grasslands and small grains croplands (e.g. wheat and barley; Lin et al 2016; Laingen 2017, Wimberly et al 2017) for corn and soybean (Glycine max L.). Some of this change can be attributed to government programs (Laingen 2011) and to the substantial increase for corn ethanol in areas with traditionally lower corn yields (Murphy et al 2011). Recent research also highlights a north and westward spatial shift in the Corn Belt (Hart and Lindberg 2014; Laingen 2017, Auch et al 2018) such that the geographic mean of the Corn Belt has shifted over 200 km northwest since the 1950s (Laingen 2017). In this paper, we build on these previous studies by presenting evidence of two key points: 1) The relative dominance of corn production of the traditional Corn Belt has been diminished, and 2) The crop reporting districts with the highest corn production have also started to shift spatially, partly from increased acreage outside the traditional Corn Belt and partly from spatial shifts in the districts with the highest corn yield trends

A perspective on changes across the U.S. Corn Belt

Corn (Zea mays L.) has long been a staple crop of the Corn Belt of the U.S., which today extends latitudinally from central Nebraska to central Ohio and longitudinally from northeast Kansas to the eastern Dakotas and western Minnesota. However, the production of corn in the Corn Belt has been transformed in both magnitude and spatial extent since the 1960s. Previous research has shown that there has been an overall increase in the number of acres planted to corn across the Corn Belt (e.g. Johnston 2014, Lark et al 2015), with a pronounced increase in the eastern Dakotas and modest increases across the historical Corn Belt, which includes most of the states of Illinois, Indiana, and Iowa (i.e. the ‘I’ states). Much of the intensification across the Dakotas can be attributed to the conversion of grasslands and small grains croplands (e.g. wheat and barley; Lin et al 2016; Laingen 2017, Wimberly et al 2017) for corn and soybean (Glycine max L.). Some of this change can be attributed to government programs (Laingen 2011) and to the substantial increase for corn ethanol in areas with traditionally lower corn yields (Murphy et al 2011). Recent research also highlights a north and westward spatial shift in the Corn Belt (Hart and Lindberg 2014; Laingen 2017, Auch et al 2018) such that the geographic mean of the Corn Belt has shifted over 200 km northwest since the 1950s (Laingen 2017).This article is published as Hunt, Eric D., Hannah E. Birge, Christopher Laingen, Mark A. Licht, Justin McMechan, William Baule, and Tom Connor. "A perspective on changes across the US Corn Belt." Environmental Research Letters 15, no. 7 (2020): 071001. doi:10.1088/1748-9326/ab9333. Posted with permission. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 license. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI