Switchgrass Biomass Yield Research Articles

Switchgrass growth and morphological changes under established pine-grass agroforestry systems in the lower coastal plain of North Carolina, United States

Switchgrass (Panicum virgatum L.) intercropped with Loblolly pine (Pinus taeda L.) has been proposed as a potential biomass feedstock for biofuel production in the southeastern United States. This study investigated effects of treatments (intercropping vs. grass only) on biomass increment processes and morphological properties of switchgrass at two experimental plots (Lenoir1) located in the coastal plain of North Carolina. We also evaluated effects of trimming lower tree branches of pine trees on switchgrass growth at another watershed-scale site (Carteret7) in the same region. Results showed that biomass yield of intercropped switchgrass was reduced by adjacent trees and negatively affected by relative position of grass to trees at the 6th year after planting at Lenoir1. Relative grass-to-tree position was also found to be a significant (p < 0.001) factor affecting grass growth at Carteret7 site with tree age of 5 years old, which is irrespective to the trimming practice. Trimming lower tree branches did not significantly (p = 0.57) improve biomass yield of switchgrass at Carteret7. We also observed intercropped switchgrass typically had higher specific leaf area and grew taller compared to grass-only plots. Stem-to-leaf ratios of switchgrass were significantly (p = 0.02) affected by trees at Lenoir1, but not by trimming lower branches in Carteret7 and relative position of grass to trees at both study sites. Findings from this study are important for evaluating the viability of producing biofuel feedstocks using this proposed intercropping system in the southeastern United States.

A Novel Delivery System for the Root Symbiotic Fungus, Sebacina vermifera, and Consequent Biomass Enhancement of Low Lignin COMT Switchgrass Lines

Sebacina vermifera (MAFF-305830) is a mycorrhizal fungus originally isolated from the roots of orchids that we have previously shown to be tremendously beneficial in enhancing biomass yield and drought tolerance in switchgrass, an important bioenergy crop for cellulosic ethanol production in the United States. Towards this end, we have developed a bentonite clay particle-based delivery system for mass production and dissemination of S. vermifera for large-scale field trials. A greenhouse-based experiment was conducted to evaluate this novel delivery method for biomass enhancement of wild type and transgenic, low lignin (COMT down-regulated) switchgrass lines compared to an efficient in vitro colonization method. S. vermifera colonization enhanced plant biomass regardless of delivery method, although the percentage of fungal biomass in planta increased with the clay-based delivery system. Further, we found that release of some clay minerals in solution was enhanced in the presence of S. vermifera, while others were seemingly reduced. Intriguingly, the presence of S. vermifera has little or no impact on cell wall composition, including lignification. This research is the first report documenting the development of a bentonite clay particle-based delivery system for mass production of any symbiotic microbe and suggests that S. vermifera can be packaged with a mineral composite and effectively delivered to a target host plant.

Application of the Smith‐Hazel Selection Index for Improving Biomass Yield and Quality of Switchgrass

ABSTRACTApart from the importance of switchgrass (Panicum virgatum L.) as forage for livestock, it is useful as a high‐value cellulosic biofuel feedstock. Breeding for a biofuel crop is complicated by the existence of multiple platforms for conversion of biomass to energy. Our main objective was to investigate the relative merits of single‐trait selection, correlated response to selection, and Smith‐Hazel‐index‐based selection for the following traits: biomass dry matter yield (YLD), ethanol (ETOH), Klason lignin (KL), and high heating value (HHV). The genetic analysis was based on a 2‐yr data set generated from evaluation of 144 half‐sib (HS) families in sward‐plot trials at Arlington and Marshfield, WI. There was significant (P &lt; 0.05) additive genetic variation among the families for all traits and for family × site interaction for the traits HHV and YLD. The estimates of narrow sense heritability on a HS family mean basis ranged from 0.37 for YLD to 0.51 for KL. Genetic correlation of YLD with ETOH, HHV, and KL were 0.38, 0.27, and 0.01, respectively. The index constructed to increase YLD and ETOH and reduce KL was most successful for a fermentation platform. This index enabled identification of families for enhancing ethanol production that would have been missed if selection was based solely on YLD. The index weighted to increase YLD and KL best suited a combustion platform. Both of these two indices had economic impacts superior to any other selection index evaluated.

PvTB1, a Teosinte Branched1 Gene Homolog, Negatively Regulates Tillering in Switchgrass

Switchgrass belongs to the family Poaceae and genus Panicum, and is a highly versatile grass used for soil and water conservation, livestock production, and biomass production for energy conversion. Tillering plays an important role in determining the morphology of the aboveground parts and the final biomass yield of switchgrass. In this study, we first cloned and identified PvTB1, a teosinte branched1 (TB1) gene homolog in switchgrass, based on its sequence similarity with the TB1 gene, which is involved in lateral branching in maize. Similar to other TB1 genes, the PvTB1 gene encoded putative transcription factors containing a basic helix-loop-helix type of DNA-binding motif called the TCP domain. Tiller emergence and development were obviously inhibited by overexpression of PvTB1 in transgenic plants, and the mutated phenotypes could be rescued using 6-benzylaminopurine. Overexpression or suppression of PvTB1 through a transgenic approach resulted in changes in tiller number, stem height, stem diameter, and biomass yield. Taken together, our results suggest that PvTB1 negatively regulates tillering in switchgrass, presumably via its expression in axillary buds.

Switchgrass Establishment and Biomass Yield Response to Seeding Date and Herbicide Application

Weed interference is a major challenge in the establishment of switchgrass (Panicum virgatum L.). A field experiment was conducted in 2011–2012 and 2012–2013 growing seasons to study the response of switchgrass to seeding date (November, May, June, and July) combined with pre‐emergence (PRE) application of atrazine (A) [6‐chloro‐N‐ethyl‐N’‐(1‐methylethyl)‐1,3,5‐triazine‐2.4‐dimine] and quinclorac (Q), or PRE A+Q followed by post‐emergence (POST) application of 2,4‐D ([2,4‐dichlorophenoxy] acetic acid) and dicamba dicamba (3,6‐dichloro‐o‐anisic acid). Switchgrass tiller density was increased with delaying the seeding date until July (194 tiller m−2) in 2012; however, no significant differences in tiller density were observed among seeding dates in 2013. Switchgrass was more morphologically developed (plant height and adventitious root numbers) at earlier seeding dates (November and May) compared with later seeding dates. Weed biomass was reduced by 18% as a result of application of PRE A+Q followed by POST compared with PRE A+Q treatment. The highest weed biomass was recorded from May seeding date in both years. The highest switchgrass biomass yield was consistently obtained from May (0.87 and 1.38 Mg ha−1 in 2012 and 2013, respectively) and June seeding dates (0.66 and 1.22 Mg ha−1 in 2012 and 2013, respectively). Our results suggested that although higher tiller density and lower weed biomass was observed with later planting date, switchgrass was more morphologically developed and produced higher biomass yield when seeded earlier. To ensure a successful long‐term switchgrass establishment an early seeding date (May) and application of PRE A+Q followed by POST 2,4‐D and dicamba could be a sustainable management practice.

Harvest Date Effects on Biomass Yield, Moisture Content, Mineral Concentration, and Mineral Export in Switchgrass and Native Polycultures Managed for Bioenergy

Various local factors influence the decision of when to harvest grassland biomass for renewable energy including climate, plant composition, and phenological stage. However, research on biomass yield and quality related to a wide range of harvest timing from multiple environments and years is lacking. Our objective was to determine the effect of harvest timing on yield, moisture, and mineral concentration of switchgrass (Panicum virgatum L.) and native polyculture biomass. Biomass was harvested on 56 unique days ranging from late summer (2 September) to late spring (20 May) spanning 3 years (2009 to 2011) and seven sites in Minnesota, USA. Biomass yield varied considerably by location and year (range = 0.7–11.7 Mg ha−1) and was lowest during the winter. On average, there was no difference in biomass yield harvested in early fall compared to late spring. Biomass moisture content was lowest in late spring, averaging 156 g kg−1 across all locations and years when harvested after 1 April. Biomass N concentration did not change across harvest dates; however, P and K concentrations declined dramatically from late summer to late spring. Considering the economic costs of replacing exported minerals and changes in revenues from biomass yield through time, biomass harvest should be conducted in late summer–early fall or late spring and avoided in winter. However, biomass managed for gasification should be harvested in spring to reduce concentrations of minerals that lead to slagging and fouling. Changes in biomass yield and quality through time were similar for switchgrass and native polyculture biomass. These biomass harvest recommendations are made from data spanning multiple years and locations and should be applicable to various growing conditions across the Upper Midwest.

Assessing winter cereals as cover crops for weed control in reduced-tillage switchgrass establishment

Weed pressure is a major challenge in switchgrass (Panicum virgatum L.) establishment. The objective of this study was to assess whether cereal cover crops alone can control weeds and improve switchgrass stand establishment in reduced-tillage system or whether herbicide treatments should be applied. Field experiments were conducted at the University of Massachusetts Agricultural Experiment Station in Deerfield in 2010–2011 and 2012–2013 growing seasons. A split plot design with three replications was used. The main plots consisted of three cover crop treatments [fallow, oat (Avena sativa L.) and rye (Secale cereale L.)]. The sub-plots were herbicide treatments that consisted of no herbicide or post-emergence application of atrazine (A) (1.1kga.i.ha−1) and quinclorac (Q) (0.37kga.i.ha−1). Herbicides were applied when switchgrass was at 4-leaf stage (6 weeks after planting). Switchgrass tiller density was 100% improved with application of A+Q. Rye provided more effective weed control than oat; however, tiller density of switchgrass was also lower in rye treatment compared with oat and fallow. Switchgrass biomass yield was significantly lower in nontreated herbicide plots (0.22Mgha−1) than plots receiving A+Q (0.41Mgha−1). Our findings suggested that supplemental herbicide application is needed with using cover crops to improve switchgrass establishment.

Erratum to: Quantitative Trait Loci (QTL) Underlying Biomass Yield and Plant Height in Switchgrass

Erratum to: Quantitative Trait Loci (QTL) Underlying Biomass Yield and Plant Height in Switchgrass

Quantitative Trait Loci (QTL) Underlying Biomass Yield and Plant Height in Switchgrass

Switchgrass (Panicum virgatum L.) biomass yield and feedstock quality improvement are priority research areas for bioenergy feedstock development. Identification of quantitative trait loci (QTL) underlying these traits and of trait-linked markers for application in marker-assisted selection (MAS) is of paramount importance in facilitating switchgrass breeding. Detection of QTL for biomass yield and plant height was conducted on parental linkage maps constructed using a heterozygous pseudo-F1 population derived from a cross between lowland Alamo genotype AP13 and upland Summer genotype VS16. QTL analysis was performed with composite interval mapping. Four QTL for biomass yield and five QTL for plant height were identified using best linear unbiased predictors across ten and eight environments, respectively. The phenotypic variability explained (PVE) by QTL detected in the across environments analysis ranged from 4.9 to 12.4 % for biomass yield and 5.1 to 12.0 % for plant height. A total of 34 and 38 main effect QTL were detected for biomass yield and plant height, respectively, when data from each environment were analyzed separately. The PVE by individual environment QTL ranged from 3.3 to 15.3 % for biomass yield and from 4.3 to 17.4 % for plant height. In addition, 60 and 51 epistatic QTL were detected for biomass yield and plant height, respectively. Significant QTL by environment interactions were detected for QTL mapped in eight genomic regions for each of the two traits. Seven QTL affected both traits and may represent pleiotropic loci. Overall, 11 genomic regions were identified that were important in controlling biomass yield and/or plant height in switchgrass. The markers linked to the main effect and epistatic QTL may be used in MAS to maximize selection gain in switchgrass breeding, leading to a faster development of better biofuel cultivars.

Variance components and heritability of biomass yield in switchgrass (Panicum virgatum L.) grown in the Southern Great Plains

Switchgrass (Panicum virgatum L.) is an important feedstock for biofuel production and also used for rangeland restoration and as a forage crop. Wide variability has been observed in switchgrass at both ecotypic and population levels. Variance component analysis can identify the relative contribution of different factors which can be used as guidance in selection of genotypes in breeding programs. The objectives of this study were to estimate and partition the sources of variance components and to estimate heritability of biomass yield in switchgrass. A total of 36 accessions including 31 plant introduction accessions collected from the Germplasm Resources Information Network (GRIN) and five improved populations developed at the Samuel Roberts Noble Foundation were used for estimating the variance components. Fourteen of these were lowland and 22 upland accessions. The accessions and populations were evaluated in Ardmore, Oklahoma from 2007 to 2011. Average biomass yield of lowland accessions was 2.41±0.05kgplant−1 and that of upland accessions was 0.57±0.01kgplant−1. Biomass yield increased up to 526% from 2008 to 2010; however, it decreased up to 88% from 2010 to 2011 growing seasons due to severe drought. Variance component analysis revealed that accessions accounted for 48.5 and 37.2% of the total variation in the lowland and upland ecotypes, respectively. Biomass yield was moderately heritable for switchgrass (0.5) and for lowland (0.6) and upland (0.44) ecotypes, indicating that biomass yield could be improved through selection. In general, lowland ecotypes are more productive; however, a few upland accessions (e.g., PI 476294, PI 657660, PI 642193) were found productive even during dry years, albeit less biomass was produced than lowland ecotype.

Biomass Production of Switchgrass in Saline-Alkali Land

A field experiment was carried out to study the growth characteristics of switchgrass cultivated in saline-alkali lands. The results show that: the survival rate, plant height, tiller numbers per plant and biomass yield of switchgrass significantly reduce with the increasing magnitude of salinity-alkalinity stresses. Switchgrass can grow in saline-alkali environments, the survival rate is more than 85%, and the overwintering rate is more than 95%. Switchgrass plants grow better in mild and moderate saline-alkali lands, and it achieve the highest biomass yield and theoretical ethanol yield of 14.3 t/ha and 5958.8 l/ha respectively, in the third year. With saline-alkali stress, ash and lignin content of switchgrass biomass increase, calorific value, cellulose and hemicelluloses content of switchgrass biomass decrease, and fuel quality of switchgrass biomass reduce to a certain extent.

Reciprocal Effects for Biomass Yield in Lowland Switchgrass

ABSTRACTSwitchgrass (Panicum virgatum L.) cultivar research is focused on improvement in biomass yield and feedstock composition for bioenergy use. These improvements could be achieved by exploiting additive and non‐additive effects of nuclear genes, as well as reciprocal differences. The objective of this study was to evaluate the influence of reciprocal effects on biomass yield in lowland switchgrass. Forty‐six biparental crosses and their reciprocals were evaluated at two locations in south‐central Oklahoma using a honeycomb design. The trial was established in the summer of 2007, and year‐end biomass yields were recorded during 2008 and 2009. The mean DNA content of the parents ranged from 1.96 to 3.70 pg, confirming that the parental genotypes were tetraploid. Ten of the 46 crosses demonstrating favorable reciprocal effects (P ≤ 0.10) had &gt;12% biomass yield advantage. The direction of reciprocal difference was fairly consistent across locations by years. The relative advantage of using a certain genotype as the female parent depended on the genetic background of the other genotype used in crossing, indicating the complex genetics of reciprocal effects. The hybrids from parent ‘LL43’ in crosses with ‘LL126’ and ‘LL22’ produced an average of &gt;40% biomass when used as the pollen parent rather than using it as the female. Evaluation of genotypes of interest for reciprocal effects by crossing with several other genotypes would help identify parents with favorable maternal effects for use in development of superior synthetic or hybrid varieties.

Predictive Relationships between Plant Morphological Traits and Biomass Yield in Switchgrass

ABSTRACTCommercial viability of switchgrass (Panicum virgatum) as a biofuel will require further improvements of biomass yield to improve sustainability. Direct selection for biomass yield in switchgrass has proven difficult due to the many factors influencing biomass yield. The identification of morphological traits associated with biomass yield could increase the efficiency of breeding efforts if these traits can be used as indirect selection criteria. By allowing increased screening and greater intensity of selection for biomass yield within spaced‐plant nurseries, these results may impact how phenotypic selection is used for switchgrass cultivar development. The objective of this research was to identify morphological traits in parental plants that are predictive of biomass yield in progeny swards. Results of this research demonstrate the challenges of selecting for increased biomass yield in switchgrass within spaced‐plant nurseries. Limited predictive ability was observed using individual and combinations of plant morphological traits. Comparisons of models with varying subsets of traits revealed common traits among the best predictive models including plant height, single‐plant dry biomass, and second leaf width. Predictions of single‐plant biomass, using the same set of morphological traits, revealed a large effect for tillering related traits. The observation that different traits affect biomass yield differently in the two planting types may indicate an effect of plant competition on the relationship of these traits with biomass yield. While these traits can help guide selections for a preferred plant ideotype, additional efforts to improve selection schemes for increasing biomass yield will be necessary for sustained genetic gain in switchgrass.

Selection for Biomass Yield in Upland, Lowland, and Hybrid Switchgrass

ABSTRACTSwitchgrass (Panicum virgatum L.) is a candidate for cellulosic bioenergy feedstock development in many parts of North America, Europe, and Asia. Breeding for increased biomass yield is a viable and desirable research objective to improve both economic and energy yields per hectare. The objectives of this study were to estimate progress from (i) selection for biomass yield in upland switchgrass, (ii) selection for winter survival, biomass yield, and biomass quality in lowland switchgrass, and (iii) advanced‐generation heterosis effects in four upland × lowland hybrid switchgrass populations. Selection for increased biomass yield in upland switchgrass resulted in mean genetic gains for of 0.71 Mg ha−1 per cycle (8% per cycle = 4% yr−1) for biomass yield. Selection for increased biomass yield in lowland switchgrass resulted in mean genetic gains of 0.89 Mg ha−1 (18% = 1% yr−1) for biomass yield. Mean high‐parent heterosis between upland and lowland ecotypes was 3.57 Mg ha−1 (43%). These gains in biomass yield resulted in significant increases in ethanol production for a fermentation platform or high heating value for a combustion platform. Biomass yield is a moderately heritable trait in switchgrass and it can be readily improved in both upland and lowland populations using conventional breeding methods.

Inheritance of Secondary Morphological Traits for Among‐and‐Within‐Family Selection in Upland Tetraploid Switchgrass

ABSTRACTMajor efforts are currently being undertaken to improve biomass yield in switchgrass. Among‐and‐within‐family selection has been proposed as an efficient selection scheme to increase rates of genetic gain. The objectives of this study were to estimate the heritability of three yield‐related traits (plant height, tiller count, and flowering date) and evaluate the suitability of those traits as within‐family‐selection criteria. Divergent selections of parents were made for each trait from an upland‐tetraploid population developed for use in temperate North America. Progeny from these selections were used to estimate narrow‐sense heritability by both parent–progeny regression and response to selection. Moderate heritability (0.41) was estimated for plant height but was greater for selection of increased height. Heritability for tiller count was low overall (0.06), with greater values observed for reduced tillering selections. Flowering date was estimated to have high heritability (0.75) overall in both selection directions. Plant height and flowering date both appear heritable on a spaced‐plant basis and may be effective selection criteria for within‐family selection. The relative value of among‐and‐within‐family selection within a practical breeding program will vary depending on what selection criteria are used and the timing of selections.

Managing Spatial and Temporal Switchgrass Biomass Yield Variability

Biorefineries that plan to use switchgrass exclusively will encounter year-to-year variability in feedstock production. The economic success of the biorefinery will depend in part on the ability of the management team to strategically identify land for conversion from current use to the production of switchgrass enabling a flow of feedstock for the life of the biorefinery. The objective of this research is to determine the optimal quality, quantity, and location of land to lease while considering the spatial and temporal variability of switchgrass biomass yield. A calibrated biophysical simulation model was used to simulate switchgrass biomass yields for 50 years based on historical weather data from 1962 to 2011, for three land capability classes for each of 30 counties. Mathematical programming models were constructed and solved to determine the optimal leasing scheme for each of three strategies for a biorefinery that requires 2,000 Mg/day. As expected, a model based on the assumption that the average yield would be obtained in each year finds that production from land identified for leasing would be insufficient to fulfill the biorefinery’s needs in half of the years. In the absence of other sources of biomass, the feedstock shortage would require forced idling of the biorefinery for an average of 29.5 days during these years. Results of a strategy of leasing sufficient land to cover feedstock needs in the worst year from among 50 years for which data are available are compared to that of a strategy enabling year-to-year storage.

Nitrogen use in switchgrass grown for bioenergy across the USA

The effect of nitrogen (N) fertilizer on switchgrass biomass production has been evaluated in a number of locations on a small-plot scale; however, field-scale information regarding switchgrass response to N and N use efficiency (NUE) in different regions of the USA is limited. Switchgrass was planted in South Dakota (SD), New York (NY), Oklahoma (OK), and Virginia (VA) in 2008 and in Iowa (IA) in 2009. Three N levels (0, 56, and 112 kg ha−1) were applied to 0.4–0.8 ha plots at each location beginning in spring the year after planting. Biomass production, N removal, apparent N recovery (ANR), and NUE were determined at all locations. Biomass yield response to N varied among locations and varied according to initial soil N concentration. Low initial soil N concentration increased biomass yield response to N fertilization, while high initial soil N concentration reduced this response. High amounts of initial soil N caused fertilizer N removal to be low. Fertilizer N uptake in switchgrass might be inhibited by competition from initial soil N. Seasonal temperature and precipitation were not strongly correlated with biomass yield and N-use of switchgrass at the studied locations. In this study, ANR was below 10% at all locations and years. Nitrogen-use efficiency was significantly related to initial soil N. High NUE was observed at locations where initial soil N was low. These data suggest that NUE depends on site-specific N management strategies that are responsive to soil N supply and plant N status.

Transmission of Switchgrass mosaic virus by Graminella aureovittata

Switchgrass mosaic virus (SwMV) was identified in switchgrass (Panicum virgatum) and was proposed as a new marafivirus based on its genome sequence and comparison with its closest relative, Maize rayado fino virus (MRFV), a type member of the genus Marafivirus. MRFV only infects maize (Zea mays) and its wild relatives, and is naturally transmitted by a corn leafhopper, Dalbulus maidis. Proving that SwMV is transmitted by a different species of leafhopper than D. maidis would provide additional evidence that SwMV is a new species of the genus Marafivirus. In 2010, three leafhopper species were identified in switchgrass fields near Champaign, Illinois – Graminella aureovittata, Graminella mohri and Flexamia atlantica. Switchgrass mosaic virus was detected by two independent RT–PCR assays in 100% of G. mohri and F. atlantica, and 95% of G. aureovittata. Twenty specimens of each species were evaluated. Of the three leafhoppers, only G. aureovittata transmitted the virus to ‘Cave in Rock’ switchgrass plants in a growth chamber. Transmission efficiency was 80% and only one of the eight SwMV-infected plants displayed mosaic/yellow streak symptoms. Switchgrass mosaic virus was detected in 78% and 83% of the switchgrass plants in the two fields from which the leafhoppers were collected. The detection of a leafhopper vector of SwMV will facilitate the transmission of the virus and the study of its impact on switchgrass biomass yield.

Field‐scale potassium and phosphorus fluxes in the bioenergy crop switchgrass: Theoretical energy yields and management implications

AbstractOur understanding of how mineral nutrition affects productivity and composition of bioenergy crops grown on marginal lands remains fragmented and incomplete despite world‐wide interest in using herbaceous biomass as an energy feedstock. Our aim was to determine switchgrass (Panicum virgatum L.) biomass production and maize (Zea mays L.) grain yield on marginal soils used previously to evaluate the effect of soil phosphorus (P) and potassium (K) fertility on alfalfa (Medicago sativa L.) forage production. Grain yield of maize was reduced on P‐ and/or K‐limited plots that also impaired alfalfa forage yield, whereas switchgrass biomass yields were high even in plots possessing very low available P (4 mg kg–1) and K (&lt; 70 mg kg–1) levels. Linear‐plateau regression models effectively described the relationship of soil test P and K to tissue P and K concentrations, and tissue P and K concentrations accurately predicted removal of P and K in harvest biomass. However, neither soil‐test P and K, nor tissue P and K concentrations were effective as diagnostics for predicting switchgrass biomass yield nor could soil tests and their change with cropping predict nutrient removal. Concentrations of cellulose, hemicellulose, lignin, and ash were not influenced by P and K nutrition. Predicted bio‐ethanol production was closely associated with biomass yield whereas high biomass K concentrations reduced estimated bio‐oil production per hectare by as much as 50%. Additional research is needed to identify diagnostics and managements to meet the bioenergy production co‐objectives of having high yield of biomass with very low mineral nutrient concentrations (especially K) while sustaining and improving the fertility of marginal soils.

Plant Mortality and Natural Selection May Increase Biomass Yield in Switchgrass Swards

ABSTRACTSwitchgrass (Panicum virgatum L.) is an important candidate for bioenergy feedstock production, prompting significant efforts to increase the number of breeding programs and the output of those programs. The objective of this experiment was to determine the potential utility of natural selection for survivorship in switchgrass swards as a tool for improving efficiency of progeny‐test‐based recurrent selection programs in switchgrass. One hundred random surviving plants were selected from 5‐yr‐old plots of six cultivars grown at five locations. Progeny of each population were grown in a four‐location field experiment in Illinois and Wisconsin in direct comparison to their parent populations. On average, natural selection for survivorship increased biomass yield by 6.7%. The northernmost (i.e., coldest) selection location had the greatest response among the five locations (13.2%) while the most genetically diverse cultivar had the greatest response among the cultivars (23.5%). Results were highly variable among cultivars and selection locations, but there were no significant negative responses, suggesting that the genetic correlation between survivorship and biomass yield in switchgrass ranges from zero to some positive value. Selection for survivorship within switchgrass sward plots has the potential to improve efficiency of family‐based selection methods designed to improve biomass yieldpotential.