Current knowledge of yield potential and best agronomic management practices for perennial bioenergy grasses is primarily derived from small-scale and short-term studies, yet these studies inform policy at the national scale. In an effort to learn more about how bioenergy grasses perform across multiple locations and years, the U.S. Department of Energy (US DOE)/Sun Grant Initiative Regional Feedstock Partnership was initiated in 2008. The objectives of the Feedstock Partnership were to (1) provide a wide range of information for feedstock selection (species choice) and management practice options for a variety of regions and (2) develop national maps of potential feedstock yield for each of the herbaceous species evaluated. The Feedstock Partnership expands our previous understanding of the bioenergy potential of switchgrass, Miscanthus, sorghum, energycane, and prairie mixtures on Conservation Reserve Program land by conducting long-term, replicated trials of each species at diverse environments in the U.S. Trials were initiated between 2008 and 2010 and completed between 2012 and 2015 depending on species. Field-scale plots were utilized for switchgrass and Conservation Reserve Program trials to use traditional agricultural machinery. This is important as we know that the smaller scale studies often overestimated yield potential of some of these species. Insufficient vegetative propagules of energycane and Miscanthus prohibited farm-scale trials of these species. The Feedstock Partnership studies also confirmed that environmental differences across years and across sites had a large impact on biomass production. Nitrogen application had variable effects across feedstocks, but some nitrogen fertilizer generally had a positive effect. National yield potential maps were developed using PRISM-ELM for each species in the Feedstock Partnership. This manuscript, with the accompanying supplemental data, will be useful in making decisions about feedstock selection as well as agronomic practices across a wide region of the country.

Annual bluegrass (Poa annua L.) may be the most troublesome and studied weed on golf courses in the United States. Given the genetic variability of annual bluegrass and its ability to adapt to different environments, it is important to understand how control methods vary across environments or regions. Our objective was to evaluate seven season‐long regimes of herbicide or growth regulators for annual bluegrass control in creeping bentgrass (Agrostis stolonifera Huds.) putting greens over 3 or 4 years in three states in the midwestern United States. Depending on the product, applications were made as often as every 2 weeks from April through September. Effectiveness of treatments varied widely by location and time, with treatments most effective in Indiana and Nebraska. Paclobutrazol was the most effective plant growth regulator for annual bluegrass control, followed closely by flurprimidol. Intermediate at reducing annual bluegrass was flurprimidol + trinexapac‐ethyl and trinexapac‐ethyl was ineffective. Among herbicides, the now discontinued experimental cumyluron was most effective and four applications of bispyribac‐sodium at 2 oz/acre every 2 weeks in August and September was more effective than 1 oz/acre applied every 2 weeks from May through September or applications of cumyluron. Though a number of products will reduce annual bluegrass on golf greens, overall control was relatively low, reinforcing the need to maximize cultural practices before attempting chemical control. Furthermore, our results reinforce the importance of superintendents’ experimenting and refining treatment regimes in their specific location to maximize efficacy.

Core Ideas Research done on annual bluegrass (ABG) control in other areas of the US are likely applicable to Nebraska. However, extreme weather can dramatically affect short‐term annual bluegrass cover and emphasize the need for long‐term control studies. Three fall POST applications of mesotrione plus prodiamine applied preemergence in August and/or November were effective for ABG control in Kentucky bluegrass fairways. Replacing mesotrione with ethofumesate was also effective when combined with prodiamine in August and November. June applications of bispyribac‐sodium at 4 oz/ac was highly effective for controlling ABG in creeping bentgrass fairways, and adding two more fall applications at the same rate improved control slightly, but there was no benefit to raising the rate to 6 oz/ac. Annual bluegrass (Poa annua L.) (ABG) is common in golf courses, and its control has been thoroughly researched in cool‐season turf east of the Mississippi River in the United States. However, ABG response to herbicides varies widely among environments and/or biotypes, and little ABG control research has been done in the northern Great Plains. Therefore, our objective was to validate ABG herbicide control systems in golf course fairways of Kentucky bluegrass (Poa pratensis L.) (KBG) or creeping bentgrass (Agrostis stolonifera L.) (CBG) in Nebraska. Preemergence (PRE) treatments of prodiamine or mesotrione were applied in late summer over 3 yr with or without fall postemergence (POST) treatments of mesotrione or ethofumesate for ABG control in a low‐mow KBG fairway. We also evaluated rate and frequency of bispyribac‐sodium applications with or without a late summer–applied PRE (dithiopyr) in early September for ABG control over 3 yr in a CBG fairway. Our research indicates that ABG control work done in other areas are likely applicable to Nebraska. Three fall POST applications of mesotrione plus prodiamine applied as a PRE in August and/or November was effective for ABG control in KBG fairways. Replacing mesotrione with ethofumesate was also effective when combined with prodiamine in August and November. June applications of bispyribac‐sodium at 4 oz/ac were highly effective for controlling ABG in CBG fairways, and adding two more fall applications at the same rate improved control slightly, but there was no benefit to raising the rate to 6 oz/ac. Lastly, extreme weather in one summer and one winter dramatically affected short‐term ABG cover and emphasized the need for long‐term control studies in areas with dramatic weather cycles.

Preemergence (PRE) herbicides are used to control crabgrass (Digitaria spp.). Single spring applications are common in areas with relatively low crabgrass pressure, whereas sequential applications often are used to extend control in locations with high crabgrass pressure. Our objectives were to determine if changing a.i. in initial and sequential applications affects crabgrass control and if single spring applications of tank-mixed PRE herbicides provide season-long crabgrass control. Studies were conducted 2009, 2010, and 2011 in West Lafayette, IN, and 2011 in Wymore, NE. The PRE herbicides prodiamine, pendimethalin, and dithiopyr were tested using different application strategies. Sequential applications were applied mid-April and mid-June using all possible combinations of the three herbicides and untreated for the initial and sequential application. These herbicides also were applied mid-April as single full-rate PRE application or as a tank mixture of two PRE herbicides at half-plus-half or half-plus-quarter rate. Season-long crabgrass control was consistently achieved using sequential applications regardless which of the three herbicides was used for initial or sequential applications. Single applications of tank mixtures also provided consistent crabgrass control, equivalent to single full-rate applications of the individual PRE herbicides. Tank mixtures of half-plus-quarter rate and single half-rate applications resulted in more crabgrass cover than single full-rate or half-plus-half rate applications regardless of the herbicide applied.

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