Energycane and biomass sorghum are two of the most promising cellulosic energy crops in the southeastern US. This study aims to determine the biomass loss and composition change of energycane and biomass sorghum in storage under different environments. Aerobic and anaerobic storage trials were conducted in seven locations across the southeastern US for energycane and six locations for biomass sorghum for 3, 6 and 9 months. Results revealed that crop type accounted for less than 3% of the variability in moisture content and biomass loss, suggesting similar storage characteristics between energycane and biomass sorghum. Average moisture content decreased from 60.7 to 50.4% after 9 months in covered aerobic storage piles but increased from 62.9 to 67.2% for anaerobic storage in anaerobic silage bags. Dry matter loss averaged 49.9% after 9 months of aerobic storage and 40.3% for anaerobic storage. Dry matter loss was described as a non-linear function of storage duration and average storage moisture, with greater loss for longer duration and higher storage moisture. Average changes in biomass composition for cellulose, hemicellulose, lignin, and ash were all less than 3% during the 9-month storage regardless of storage types. Results from this study provide valuable insights on changes in biomass quantity and quality during storage and fill a critical knowledge gap in addressing the challenge of year-round biomass supply to biorefineries.

This study aims to provide a comprehensive analysis on the potential of energycane and biomass sorghum to support biorefinery development in Southeast US. Land parcels most competitive for energycane and biomass sorghum production were identified through field-level simulations by incorporating cropland distribution, soil and historic weather data. Biomass and moisture dynamics during growing season, post maturity, and storage were used to develop year-round biomass supply plans with different biomass storage options. Just-in-time harvest accounted for 16 %, 32 % and 40 % of total harvested biomass for silo bag (low-loss), bunker silo (medium-loss), and pile (high-loss) storage options, respectively, with the remaining 84 %, 68 % and 60 % from storage. Net profit optimization was used to identify top 10 highest ranked sites in each state. They are mostly located along the coastal areas of Texas and Louisiana, southern Georgia, central Florida, and east of the Mississippi River in the Mississippi Delta. Profits are greatly impacted by weather variability, land productivity, and storage characteristics. Top sites with high net profits are located in Texas, Florida, Louisiana, and Georgia, while Mississippi has the lowest net profits. This study represents a first comprehensive analysis that incorporates biomass and moisture dynamics in the crop season and during storage on the potential of energycane and biomass sorghum to support biorefinery development in the Southeast US. It offers critical insights into how weather variability, cropland distribution and productivity, and biomass storage affect profitability and presents a blueprint for optimizing biorefinery site selection and improving tactical and operational planning for bioenergy development in the Southeast US.

The southeastern United States holds immense potential for producing cellulosic feedstocks to support the emerging biofuel industry. However, the development of a viable cellulosic biofuel sector depends on consistent, site-specific, and seasonally available biomass supply. Biomass sorghum has emerged as a promising annual feedstock, but understanding its growth dynamics and environmental sensitivities is essential for optimizing yield and supply logistics. A four-year, multi-location study was conducted across six sites in the southeastern US to assess the influence of genotype, environment, and management on biomass sorghum growth and productivity. The objectives were to: (1) quantify the growth and biomass dynamics of biomass sorghum under different environments in the Southeast US and 2) estimate early harvest yield penalties based on its seasonal biomass growth patterns. Stalk density and plant height varied significantly across sites, years, and genotypes, reflecting strong genotype × environment interactions. Biomass accumulation followed a sigmoid growth pattern, with differences in heat unit requirements and the number of days to reach maximum biomass yield. Northern sites exhibited faster biomass accumulation but shorter growing seasons and higher early harvest penalties of up to 25

Energycane and biomass sorghum are two of the most promising cellulosic energy crops in the southeastern US. Research on these two energy crops has focused mainly on biomass production, and there is a lack of knowledge on their ability to promote biodiversity and ecosystem services. This paper presents results from a comprehensive study on ground-active arthropod diversity in seven sites across five states in the southeastern US (Florida, Georgia, Louisiana, Mississippi, and Texas). Pitfall traps were deployed four times during each crop season for energycane, biomass sorghum, and a local reference conventional crop from 2020 to 2022. Arthropod abundance (individuals/(trap × day)) values were 4.9 ± 0.46, 3.7 ± 0.18, and 2.6 ± 0.16 (mean ± stderr) for conventional crops, biomass sorghum, and energycane, respectively, with a significant difference found only between conventional crops and energycane. Individuals were identified to arthropod orders, and Hill’s diversity indices were calculated based on the number of individuals in each arthropod order instead of the number of individuals in each arthropod species. Order-based arthropod richness values were 5.3, 5.2, and 4.8 for biomass sorghum, conventional crops, and energycane, with significant difference found only between biomass sorghum and energycane. There was no significant difference in the order-based Shannon diversity and Simpson diversity between the three crop types. The effective number of arthropod orders for the two energy crops decreased from 5.0 to 3.4 to 2.9 with increasing order of diversity from arthropod richness to Shannon diversity to Simpson diversity. The explained variability by environmental factors also decreased with increasing Hill’s order of diversity. The results from this study indicate no significant advantage in order-based arthropod diversity in growing biomass sorghum and energycane. This research fills a critical knowledge gap in understanding the impacts of cellulosic energy crop production on biodiversity and ecosystem services.

Saccharum is relatively new to 33° N latitude. S. spontaneum readily hybridizes with commercial sugarcane (Saccharum spp.) and lends cold tolerance and greater yield to the hybrid progeny, called energycane. Since 2007, there have been numerous new hybrid and backcross energycane genotypes developed but there is a paucity of information about them. Twenty energycane genotypes were tested in the first season of growth from cane propagules (plant cane; PC) against Ho 02-113 (a control) for two site-years in northcentral Mississippi. Grand (exponential) growth continued into October. The prevailing paradigm is that tonnage is what matters. Except for percentage cellulose, all factors tested (dry matter yield, extractable juice volume, °Brix, theoretical ethanol from fermentation, theoretical ethanol from cellulose, and total theoretical ethanol) were greater from the second site-location compared to the first. Dry matter yield (DMY) and total theoretical ethanol yield (TTEY) were moderately correlated. Over the two years of this test only Ho 14-9213 exceeded in mean DMY of Ho 02-113. Sixteen of the 19 test genotypes in this test equaled or exceeded the mean TTEY of Ho 02-113.

'Espresso' (Reg. no. CV-293, PI 687202) is a lowland ecotype (Gulf sub-population) of switchgrass (Panicum virgatum L.) developed and released by Mississippi State University and the Mississippi Agricultural and Forestry Experiment Station. Espresso was developed from seven cycles of phenotypic recurrent selection for rapid seed germination without stratification. All cycles of selection were made using seed harvested from open-pollinated isolation blocks containing approximately 100 mother plants. Germination was assessed in laboratory conditions for 15 years, culminating in 2 years of field-based germination and emergence evaluation at five locations across Mississippi. Over a 2-year period, germination and emergence of Espresso was significantly greater (P < 0.05) than seed from 'Alamo' and 'Kanlow'. Field testing revealed Espresso as having significantly (P < 0.05) greater establishment success (mean number of seedlings per linear 30 cm) when compared to Alamo. Espresso was released based on the need for southeastern US-adapted germplasm that possesses enhanced germination characteristics.

Carinata (Brassica carinata A. Braun) is an emerging oilseed crop with potential as a dual use winter cover/cash crop in the southeastern US region. Although carinata is historically cultivated as a spring crop in northern latitudes, incorporating carinata into southeastern US cropping systems can provide winter/cover ecosystem services and a bio-feedstock for a high value, renewable aviation fuel without displacing feed and food crops. In this study, our major objective was to quantify the agronomic performance and stability of selected carinata genotypes across several locations in the southeastern US. Extensive field evaluations of twelve, elite carinata genotypes, arranged in a randomized complete block design with four replications, were conducted from 2016 to 2019 across Mississippi, Alabama, Georgia, Florida, South Carolina, and North Carolina. Data was collected on days to 50% bolting, days to 50% flowering, plant height, grain yield, and test weight. Results demonstrated the ability to produce viable grain yields across the region, but also highlighted the impact of freezing temperatures on winter production. In total 20% of all environments were lost to mortality due to freezing temperatures. Overall, genotype 15 produced the highest grain yield across individual environments, topping the trial in 74% of all environments. However, both crossover and non-crossover genotype x environment interactions were detected for agronomic traits, with problematic crossover interactions more prevalent for days to 50% bolting and days to 50% flowering. Our results also suggest the southeastern US be separated into three mega environments to include 1) northern Georgia, South Carolina, and North Carolina, 2) southern and central Georgia and Alabama, and 3) northern Florida. Future efforts to identify advanced breeding lines and/or commercial seed products with adaptation to the region should consider field testing in each of these mega environments.

The leaf economics spectrum (LES) describes multivariate correlations in leaf structural, physiological and chemical traits, originally based on diverse C3 species grown under natural ecosystems. However, the specific contribution of C4 species to the global LES is studied less widely. C4 species have a CO2 concentrating mechanism which drives high rates of photosynthesis and improves resource use efficiency, thus potentially pushing them towards the edge of the LES. Here, we measured foliage morphology, structure, photosynthesis, and nutrient content for hundreds of genotypes of the C4 grass Miscanthus× giganteus grown in two common gardens over two seasons. We show substantial trait variations across M.× giganteus genotypes and robust genotypic trait relationships. Compared to the global LES, M.× giganteus genotypes had higher photosynthetic rates, lower stomatal conductance, and less nitrogen content, indicating greater water and photosynthetic nitrogen use efficiency in the C4 species. Additionally, tetraploid genotypes produced thicker leaves with greater leaf mass per area and lower leaf density than triploid genotypes. By expanding the LES relationships across C3 species to include C4 crops, these findings highlight that M.× giganteus occupies the boundary of the global LES and suggest the potential for ploidy to alter LES traits.

Abstract Selenium (Se)‐affected stormwater runoff raises concerns about potential downstream impact of Se on aquatic ecosystems. Unplanted (UNP) detention ponds augmented with cattail (Typha angustifolia L.; CAT) and duckweed (Lemna minor L.; DWD) may provide a solution for continuous, rapid abatement of Se‐affected runoff. This research was conducted to evaluate the efficacy of CAT or DWD and determining the distribution of Se within a continually flooded detain and drain system. Microcosms containing 3 kg of soil planted to either one CAT, 25 g fresh DWD, or left unplanted (UNP, control) were flooded with a 3‐L solution at 40 μg Se L−1, as sodium selenate (Na2SeO4), or a zero Se control. Over two 10‐d flood–discharge cycles (FDCs), plants in microcosms were evaluated in growth chambers maintained at 30 °C under a 12‐h photoperiod with 400 μmol m−2 s−1 irradiance. Initial and final water, soil, plant, and granular activated charcoal (GAC) were analyzed for total [Se] with inductively coupled plasma–mass spectroscopy (ICP–MS). Data were analyzed with PROC GLM (SAS EG 7.1) at α = .05. Within 10 d after Se application, CAT and DWD decreased aqueous Se from 40 μg Se L−1 to below the 11.8 μg Se L−1 threshold. Selenium recovery ranged between 75 and 100% of the applied Se. In continually flooded systems, the primary elimination pathway appears to be associated with the soil solid phase. Cattail and DWD are suitable species for constructed wetland phytoremediation of Se‐affected runoff. The microcosm design presented may be useful for future evaluations.

The northern bobwhite (Colinus virginianus; hereafter, bobwhite) requires intensive monitoring to evaluate management efforts and determine harvest rates. However, traditional monitoring techniques (e.g., covey-call surveys) are labor-intensive and imprecise. Small unmanned aerial systems (sUASs) mounted with thermal cameras have demonstrated promise for monitoring multiple avian species and could provide a less intensive and more effective approach to monitoring bobwhite coveys, assuming coveys produce a recognizable heat signature. To assess sUAS monitoring, we evaluated the influence of bobwhite covey size (3, 6, and 12) and cover type (grass, shrub, and forest) on covey detectability by a sUAS equipped with a thermal camera. We hypothesized that forest would have the lowest covey detection due to trees obstructing detection of the thermal signature and that larger covey size would improve covey detection due to the formation of larger, more visibly distinct thermal signatures. We placed groups of known-size, pen-reared bobwhites in steel mesh cages (3, 6, and 12 individuals/cage) in 3 vegetation types (grass, shrub, and forest) among predetermined locations on a private farm in Clay County, Mississippi, USA (3 replicates, 27 total cages). At civil twilight on 5 March 2020, the sUAS flew a systematic route over the cage area at 30 m above ground level, capturing thermal infrared photographs every 5 seconds. To assess detection, we distributed 57 photographs to 31 volunteers and asked them to assign a binary value for detection (1, 0) regarding covey presence in each photograph. Overall true positive rate was 0.551 but improved with increasing covey size. By vegetation type, simulated coveys in grass had the lowest true positive rate by photograph (0.403), followed by forest (0.562) and shrub (0.605). Results indicate that sUASs and thermal camera technology could be a viable method for surveying intact bobwhite coveys, especially if detection of smaller groups and those in denser vegetation improves. As this technology advances, we recommend that future research focus on evaluating the efficacy of this novel methodology through assessing the influence of weather conditions, camera specifications, flight speed, and altitude, as well as assessing machine learning for processing photos.

Enhancing the growth of annual ryegrass (Lolium multiflorum Lam.) would be beneficial to livestock producers to decrease supplementation. The objective of the study was to examine the effects of nitrogen (N) and gibberellic acid (GA) in biomass production and nutritive. We evaluated the application of N (0, 20, and 40 lb N acre-1) and RyzUp Smartgrass (RYZ) [gibberellic acid (gibberellin A3)] at a rate of 0.4 oz acre-1 across two growing seasons (2011-2012 and 2012-2013). The experimental design was a split-plot replicated four times. The main plots consisted of four treatment application dates (mid-December, early and late January, and mid-February) and the subplots consisted of four treatments (RYZ, 40 lb N acre-1 [40N], 20 lb N acre-1 [20N] plus RYZ, and 40N plus RYZ) and untreated control (UC). Seasonal dry matter (DM) yield was not different between UC and RYZ treatments, while N treatments had significantly greater biomass production but were not different from each other. RYZ had a 5% yield increase while 40N+RYZ had a 26% yield increase compared with UC. Treatment had a significant effect on crude protein (CP) (P < .01), neutral detergent fiber (NDF) (P = .02), and water-soluble carbohydrate (WSC) (P < .01). No differences in WSC were detected between UC and RYZ treatments, while the treatments containing N had a slight decrease in concentration. Data suggests that temperatures in the southern United States during annual ryegrass production might be too mild to observe a GA response at the applied rates.

Abstract Salinity is a critical challenge facing productivity of barley around the world, necessitating the development of salinity tolerant varieties. Screening genotypes of two barley species during germination and seedling growth stages was conducted to identify genotypes with superior performance under saline stress conditions. Five genotypes of domestic barley (Hordeum vulgare L.) and six of wild barley (H. bulbosum) were used in this study. Genotypes were germinated in solutions of 0, 1.0, 1.5, and 2.0% NaCl (0, 171, 257, and 342 mM NaCl). Shoot and root length were recorded 10 d after germination. Upon reaching the three‐leaf stage, seedlings were irrigated with 500 mM NaCl solution for 3 wk to evaluate salt tolerance using the growth index. The analysis of variance showed there was a high genetic variation among genotypes. Only genotypes PI220054, PI227242, and PI420909 of wild barley species germinated at the 2% NaCl salinity level. All domestic barley genotypes failed to germinate at 2% NaCl salinity and showed reduction of root and shoot length greater than wild barley genotypes under saline conditions. Mean root and shoot lengths decreased as the level of NaCl increased for all genotypes. This condition was more intense in domestic than wild barley genotypes. Seedling screening showed PI268243 had the greatest growth index compared with the other genotypes. The PI227242 genotype had the greatest growth index among wild barley genotypes. Regression analysis indicated that there was no relationship between salt tolerance at germination and seedling growth stages.

Orchardgrass (Dactylis glomerata L.) could serve as a cool-season perennial in southeastern production systems, but often does not behave as a true perennial under high temperature stress conditions of the region. This work sought to develop heat-tolerant orchardgrass germplasm through recurrent phenotypic selection (RPS) that would both reduce secondary seed dormancy caused by high soil temperatures and improve stand persistence over summer months. Selection was conducted in a growth chamber 40/30 degrees C (12/12 h, light/darkness), with germinated seedlings subjected to an additional 2-3 wk of 40/30 degrees C conditions. The base germplasm (Cycle 0) and selected individuals (Cycles 1-3) were transplanted into the field, then harvested for seed. Forty-degree germination tests compared mean cumulative germination, velocity of germination within 8 d (VOG(8)), and realized heritability (hRealized2). Stand persistence was assessed 1 yr after transplanting. Results from 2018 tests indicated Cycle 3 seed germination was greater (82%) than all previous cycles of selection, and VOG(8) was eight times greater than that of Cycle 0. Additive gene action also increased, with final hRealized2 = .45, and preliminary data from Cycle 3 10-mo-stand persistence (56%) was double that of Cycle 0 (27%). These results indicated a significant improvement over the base germplasm for both germination at high temperatures and stand persistence in the field. This could lead to improved stand survival and greater adoption by southeastern forage producers.

Abstract Salinity is one of the most important challenges facing future global barley (Hordeum vulgare L.) productivity, as it causes major reduction in germination, growth, grain yield, and quality. Screening germplasm for salinity tolerance at germination is vital to breeding programs because germination is the first stage of plant growth and occurs near the soil surface where salt can accumulate in high concentrations. This experiment was conducted to assess salinity tolerance of 249 genotypes (64 diploid (2×) H. vulgare crosses; 174 tetraploid (4×) H. vulgare crosses; and 11 parents) at the seed germination stage. Salinity treatments applied at imbibition included concentrations of 0, 100, 200, and 300 mM salinity and were maintained for 10 d. Analysis of variance of all families indicated significant (P ≤ .001) genotype × salinity interaction for final germination percentage (FG%), corrected germination percentage (CG%), and germination index (GI) at all treatment levels, indicating high genetic variation for salinity tolerance among screened genotypes. The mean of all measured parameters (FG%, CG%, and GI) decreased as salinity concentration increased. These responses can be used to identify genotypes with salinity tolerance at germination. At 300 mM salinity, progenies in 2× Families 1 and 2 were 14.3 and 12.5% saline tolerant, respectively. A total of 29 progenies from 4× families were tolerant to 300 mM treatment at germination. These progenies would have an economic value for improving barley tolerance for salinity.

Annual ryegrass (Lolium multiflorum Lam.) is an essential part of winter grazing systems in the southern United States. Because of an increase in nitrogen (N) cost, producers are considering decreasing fertilizer application rates while incorporating forage-type legumes as part of their grazing management system. The objectives of this study were to determine optimum management practices including N fertilizer application rate and timing and the incorporation of legume species and to assess changes in yield and nutritive value. 'Marshall' ryegrass was planted in a prepared seedbed at a rate of 25 lb pure live seed acre(-1) in the fall of 2008, 2009, and 2010. The experiment included nine N fertilization regimes such as the fall and spring application of ammonium nitrate (34-0-0). Along with an untreated check (UC), N applications (lb N acre(-1) in fall, spring, or both) included the following: 25F-0S, 0F-25S, 25F-25S, 50F-0S, 0F-50S, 50F-25S, 25F-50S, and 50F-50S lb N acre(-1). Along with fertilization treatments, annual and perennial clover (Trifolium spp.) and hairy vetch (Vicia villosa Roth subsp. villosa) were included in the study. Yields were significantly lower during the 2009-2010 season. Higher yields were observed in the 2010-2011 season when warmer temperatures occurred in the spring. Nitrogen applications produced a slight yield advantage than the clover species. The 75 lb N acre(-1) (25F-50S) application produced the highest forage mean yield. Clover treatments had a higher yield than the UC.

AbstractIncreased salinity from irrigation and poor drainage has led to reduced production in semi‐arid and arid irrigated areas of the world. The narrow genetic variation among domestic barley (Hordeum vulgare L.) genotypes slows progress in developing varieties tolerant to biotic and abiotic stresses. A wild barley relative (H. bulbosum L.) is a genetic resource with tolerance to multiple stress conditions, especially salinity. New germplasm added to the USDA barley collection allows novel breeding opportunities. However, crosses between these species require embryo rescue. Crosses were made between diploid and tetraploidized domestic barley ♀ and tetraploid bulbous barley ♂. Immature embryos were rescued and placed on Murashige and Skoog (MS) or Gamborg's B‐5 (B‐5) media (no plant growth regulators, PGRs). Analysis of variance of families showed significant effects for the genotype × medium interactions, indicating each genotype responded to each medium type independently. Significant effects were observed for some traits due to both genotype and medium; and significant effects between media for some traits were observed indicating that those traits were affected by media type. Murashige and Skoog was found to be the better medium for most crosses compared to B‐5. Generally, results from this study indicated that it is difficult to draw broad conclusions about the most suitable medium composition for a broad spectrum of genotypes due to individual genotypes responding differently to the media type. Subsequent manuscripts by these authors will address the success of fertile crossed progeny.

Annual ryegrass (Lolium multiflorum Lam.) can be divided into two cytotypes: diploid (2n = 2x) and tetraploid (2n = 4x). Polyploid versions of a given plant species result in increased seedling vigor, more robust growth and, potentially, greater yield. While most data suggest no difference in yield between diploid and tetraploid cultivars, there is still potential for weight gain advantages thanks to increased non-structural carbohydrates in tetraploid cells. The objectives of this study were to compare weight gain of cattle grazing either diploid or tetraploid cultivars of annual ryegrass. Two diploid annual ryegrass cultivars (Marshall and Tam 90) and two tetraploid cultivars (Jumbo and Nelson) were planted in 0.81-ha pastures, each replicated four times. Four steers (mean initial BW = 214 kg) were randomly assigned to each pasture for an 82-d grazing period. Body weights were recorded starting at day 0 then every 28 days throughout the season. Data were analyzed in the GLM procedure of SAS using a significance level of α = 0.05. There were significant differences between cytotypes with respect to seasonal yield with diploids (9547.90 kg/ha) yielding greater than tetraploids (7762.00 kg/ha). As expected, ADF and NDF fractions were significantly less for tetraploids (ADF; 31.39%, NDF; 31.39%) compared to diploids (ADF; 33.75%, NDF; 53.25%). Tetraploids also contained significantly greater crude protein (13.50%) than diploids (12.90%). Cytotype had no effect on final average daily gain (ADG) (P = 0.9427). However, final ADG was significantly impacted by cultivar (P = 0.0134). Final ADG for Tam 90 (1.10 kg/d) was greater than Marshall (0.92 kg/d). Cattle grazing Nelson (1.04 kg/d) and Jumbo (0.99 kg/d) did not differ. Results show that regardless of differences in seasonal yield and nutritive value between cytotypes, there were no advantages in ADG for cattle grazing either cytotype.

Native warm-season grass (NWSG) roughs provide environmental and aesthetic value to golf courses; however, weed competition is a constraint during establishment. This research evaluated the effects of common turfgrass preemergence herbicides on establishment of newly seeded 1:1 mixture of little bluestem [Schizachyrium scoparium (Michx.) Nash] and sideoats grama [Bouteloua curtipendula (Michx.) Torr.] (14.3 lb total seed acre(-1)) rough. Herbicides applied immediately after drill-seeding included: atrazine (1.0 lb a.i. acre(-1)), dimethenamid-P (1.5 lb acre(-1)), dithiopyr (0.38 lb acre(-1)), imazapic (0.06 lb acre(-1)), indaziflam (0.029 lb acre(-1)), isoxaben (1.0 lb acre(-1)), Smetolachlor (2.48 lb acre(-1)), oxadiazon (4.0 lb acre(-1)), pendimethalin (1.47 lb acre(-1)), prodiamine (0.75 lb acre(-1)), and simazine (1.0 lb acre(-1)). Effects upon NWSG plant density and biomass, as well as smooth crabgrass [Digitaria ischaemum (Schreb.) Schreb. ex Muhl.] control, were evaluated in 2017 and 2018. Across years, imazapic, dimethenamid, oxadiazon, and metolachlor controlled crabgrass >90%. In 2017, little bluestem plant density assessed 4 months after treatment was 2 to 13 times greater in imazapic-treated plots than all other treatments except for those treated with isoxaben and simazine. Application of imazapic resulted in greater little bluestem aboveground biomass than all other herbicide treatments, except simazine, in 2017. In 2018, imazapic resulted in greater little bluestem plant density than the untreated control, atrazine, prodiamine, oxadiazon, isoxaben, or simazine. Although it was a minor component of the sward, sideoats grama was generally tolerant of imazapic. Imazapic application during seeded establishment of little bluestem and sideoats grama golf course rough provides acceptable crop tolerance and smooth crabgrass control.