Biomass Yield of Switchgrass Cultivars under High- versus Low-Input Conditions

Switchgrass (Panicum virgatum L.) is undergoing development as a biomass crop to support conversion of cellulosic biomass to energy. To avoid the competition of biomass with food or feed crops, most commercialization proposals suggest that switchgrass should be grown exclusively on marginal lands that are not fit for food or feed production. The objective of this study was to investigate the potential for cultivar x environment interactions that would affect the methods and approaches for breeding and evaluating switchgrass cultivars, including both upland and lowland types, for high-input versus low-input types of environments. Biomass yield was measured on 14 cultivars that were present in 28 replicated field experiments representing seven regions, ranging from 75 to 100° W and spanning USDA Hardiness Zones 4 through 7. Region was the most important environmental factor interacting with cultivars, supporting the idea that the north-central and northeastern United States should have independent switchgrass breeding programs. Cultivars interacted with soil phosphorus concentration in New Jersey and with depth of the A and B horizons in New York and showed mild interactions with rate of nitrogen fertilizer at several locations. Cultivar rank correlation coefficients between the two rates of nitrogen fertilization (100 vs. 0 kg N ha−1) ranged from 0.23 to 0.88, suggesting a possible benefit to breeding and selection without applied nitrogen fertilizer

Biomass Production of Herbaceous Energy Crops in the United States: Field Trial Results and Yield Potential Maps from the Multiyear Regional Feedstock Partnership

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

Biomass production of herbaceous energy crops in the United States: field trial results and yield potential maps from the multiyear regional feedstock partnership

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

Biomass energy characteristics of switchgrass cultivars grown in New Jersey.

Abstract Switchgrass (Panicum virgatum L.) is a native perennial warm season grass currently being used as a bioenergy feedstock. However, little information is available on switchgrass production in the northeastern US. The objectives of this study were to evaluate the performance of three switchgrass cultivars (Alamo, Carthage, and Timber) grown for bioenergy at two locations in New Jersey. Cultivars were planted in a randomized complete block design with three replicates at two locations, Upper Deerfield and Pittstown, NJ in spring of 2007 and 2008, respectively. A single fall harvest was made at each location in 2009 and 2010. Ash, dry matter content, and high heating value were determined from subsamples of plots collected monthly after harvest. Switchgrass biomass yields ranged from 8.94 to 13.21 Mg ha -1 . Biomass yields were similar among cultivars and locations tested. Dry matter content increased after fall harvest at both locations and reached acceptable levels in January. Mean ash content ranged from 14.0 to 25.7 g kg -1 and did not differ among cultivars or subsample harvests. High heating values ranged from 19.39 to 20.08 J kg -1 , with no differences observed among cultivars or harvests. Near-infrared reflectance spectroscopy predicted ash well but not high heating value. Results indicate that Alamo, Carthage, and Timber are high yielding, low ash switchgrass cultivars that could be promising choices for biomass production in the northeastern and MidAtlantic US, and that dry, low-ash biomass can be harvested throughout the winter if weather conditions permit

Miscanthus 3 giganteus productivity: the effects of management in different environments

Miscanthus 9 giganteus is a C4 perennial grass that shows great potential as a high-yielding biomass crop. Scant research has been published that reports M. 9 giganteus growth and biomass yields in different environments in the United States. This study investigated the establishment success, plant growth, and dry biomass yield of M. 9 giganteus during its first three seasons at four locations (Urbana, IL; Lexington, KY; Mead, NE; Adelphia, NJ) in the United States. Three nitrogen rates (0, 60, and 120 kg ha -1) were applied at each location each year. Good survival of M. 9 giganteus during its first winter was observed at KY, NE, and NJ (79–100%), and poor survival at IL (25%), due to late planting and cold winter temperatures. Site soil conditions, and growing-season precipitation and temperature had the greatest impact on dry biomass yield between season 2 (2009) and season 3 (2010). Ideal 2010 weather conditions at NE resulted in significant yield increases (P \u3c 0.0001) of 15.6– 27.4 Mg ha -1 from 2009 to 2010. Small yield increases in KY of 17.1 Mg ha -1 in 2009 to 19.0 Mg ha -1 in 2010 could be attributed to excessive spring rain and hot dry conditions late in the growing season. Average M. 9 giganteus biomass yields in NJ decreased from 16.9 to 9.7 Mg ha -1 between 2009 and 2010 and were related to hot dry weather, and poor soil conditions. Season 3 yields were positively correlated with end-of-season plant height (^q ¼ 0:91) and tiller density (^q ¼ 0:76). Nitrogen fertilization had no significant effect on plant height, tiller density, or dry biomass yield at any of the sites during 2009 or 2010

A first linkage map and downy mildew resistance QTL discovery for sweet basil (<i>Ocimum basilicum</i>) facilitated by double digestion restriction site associated DNA sequencing (ddRADseq)

<div><p>Limited understanding of sweet basil (<i>Ocimum basilicum</i> L.) genetics and genome structure has reduced efficiency of breeding strategies. This is evidenced by the rapid, worldwide dissemination of basil downy mildew (<i>Peronospora belbahrii</i>) in the absence of resistant cultivars. In an effort to improve available genetic resources, expressed sequence tag simple sequence repeat (EST-SSR) and single nucleotide polymorphism (SNP) markers were developed and used to genotype the MRI x SB22 F₂ mapping population, which segregates for response to downy mildew. SNP markers were generated from genomic sequences derived from double digestion restriction site associated DNA sequencing (ddRADseq). Disomic segregation was observed in both SNP and EST-SSR markers providing evidence of an <i>O</i>. <i>basilicum</i> allotetraploid genome structure and allowing for subsequent analysis of the mapping population as a diploid intercross. A dense linkage map was constructed using 42 EST-SSR and 1,847 SNP markers spanning 3,030.9 cM. Multiple quantitative trait loci (QTL) model (MQM) analysis identified three QTL that explained 37–55% of phenotypic variance associated with downy mildew response across three environments. A single major QTL, <i>dm11</i>.<i>1</i> explained 21–28% of phenotypic variance and demonstrated dominant gene action. Two minor QTL <i>dm9</i>.<i>1</i> and <i>dm14</i>.<i>1</i> explained 5–16% and 4–18% of phenotypic variance, respectively. Evidence is provided for an additive effect between the two minor QTL and the major QTL <i>dm11</i>.<i>1</i> increasing downy mildew susceptibility. Results indicate that ddRADseq-facilitated SNP and SSR marker genotyping is an effective approach for mapping the sweet basil genome.</p></div

Frequency distribution of disease severity in the MRI x SB22 F₂ mapping population across three environments.

<p>Codes for each environment are shown on the x-axis and correspond to data recorded in 2014 in southern New Jersey (NJRA14), 2015 in southern New Jersey (NJRA15) and northern New Jersey in 2014 (NJSN14). Disease severity measured on a scale in which 0 = lowest possible severity score and 1 = highest possible severity score.</p

Detection of major downy mildew resistance QTL <i>dm11</i>.<i>1</i> across three environments.

<p>LOD scores for genome-wide scan using square-root transformed phenotype data from three environments: NJSN14 (northern New Jersey; 2014), NJRA14 (southern New Jersey; 2014) and NJRA15 (southern New Jersey; 2015). Significant LOD thresholds (α = 0.05) were calculated by permutation tests with 1,000 iterations and are shown with red, dashed horizontal lines.</p