Chemical composition and energy yield of elephant-grass biomass as function of five different production ages.

Abstract Elephant grass has high biomass production, with qualities suitable for conversion into bioenergy, but has long been used exclusively for animal feed and only in recent years has it become an energetic alternative. Therefore, it is necessary to select genotypes with potential for energy production. This study evaluated the effect of five harvest times (8, 12, 16, 20, and 24 weeks) on the yield and chemical composition related to biomass quality through combined polynomial regression analyses of the following elephant grass genotypes: Cubano Pinda, Mercker 86-México, Pusa Napier n°1, Mole de Volta Grande, P-241-Piracicaba, and King Grass. A completely randomized design with three replicates, in a split-plot arrangement, was adopted, including two factors (plots = genotypes, subplots = harvest times). The evaluated variables were whole-plant dry matter yield, in t ha-1 (DMY), percentage of neutral detergent fiber (%NDF), and percentage of acid detergent fiber (%ADF). The elephant-grass genotypes Cubano de Pinda, Mercker 86-México, and P-241-Piracicaba showed a linear first-degree effect as a function of the harvest intervals, indicating that they did not reach their maximum production potential. Genotypes Pusa Napier n°1, Mole de Volta Grande, and King Grass, in turn, had a linear second-degree effect. For the NDF variable, all genotypes showed a significant linear second-degree effect as a function of the harvest intervals, except P-241-Piracicaba, for which no regression was observed. For this genotype, there was a significant linear first-degree effect on the %ADF variable

Biomass energy production in elephant-grass hybrids.

Elephant grass is a forage plant widely spread in Brazil that was initially employed exclusively in the livestock sector as feed for cattle. This grass is characterized by its high productivity and high photosynthetic capacity. In addition to being used as forage, it has shown to be an alternative source of renewable energy. The objectives of the present study were to evaluate the morpho-agronomic traits of elephant grass hybrids and their parents for biomass energy production. The experiment was conducted in a randomized-block design with three replicates. The partial diallel was composed of 16 hybrids and two groups (males and females). Data were subjected to analysis of variance and the Tukey?s mean comparison test (P < 0.05). Interaction was detected by the F test for the traits dry matter yield, plant height, and leaf width. Based on the mean values, hybrids H11 and H14 seem to be promising for dry matter production for energy purposes. Parent Porto Rico 534-B can be indicated in breeding programs

Estimate of genetic diversity in germplasm of elephant grass accessions in Brazil using the Gower algorithm.

Management of variability in germplasm banks is essential for genetic improvement, so that the breeder can estimate the genetic similarity between cultivars, as well as maintain genetic diversity in breeding programs. Elephant grass is a forage crop plant native to Africa of great socio-economic and environmental importance; it can be used for animal feed and for bioenergy production. Understanding the genetic variability of elephant grass is essential for breeding programs. In this context, we examined the genetic divergence of elephant grass accessions using the Gower algorithm. The experiment was conducted under field conditions in the municipality of Campos dos Goytacazes-RJ, Brazil. All 85 elephant grass accessions belonging to the Active Elephant Grass Germplasm Bank of Embrapa Gado de Leite were included. These genotypes are commercial varieties from various countries. They were evaluated for morphoagronomic, morphological and phenological characteristics. The experimental design was randomized blocks with two repetitions. The plots were composed of 5.5-meter rows, with 2.0-meter spacing between the planting rows, totaling 11.0 m2 . The useful area was a sample in the center of the plot. We generated an illustrative dendrogram, obtained by the UPGMA method and the Tocher clustering, based on the Gower algorithm. Data were examined by means of the GENES statistical programs and the R program. According to the dissimilarity matrices based on the Gower algorithm, the genetic distances varied between 0.08 and 0.56, and the mean distance of the 85 evaluated accessions was 0.25, suggesting, consequently, that there is wide genetic variability between the accessions. Of the 85 genotypes, seven presented genetic distances smaller than 0.1, being indicative of duplicates in the germplasm bank, which could be eliminated without risk of loss of genetic variability

Growth curve in elephant grass genotypes based on morpho-agronomic traits for energy production.

The elephant grass (Cenchrus purpureus (Schumach.) Morrone) is one of the species with great prominence for energy production because of its favorable traits, such as high yield and short cycle, combined with several biomass quality characteristics. Therefore, this study intended to evaluate the morpho-agronomic traits of eight elephant grass genotypes under different cutting ages. A randomized block design with three replicates was applied to the experiment, and plots were composed of a 12 m long line divided into six subplots for each of the bimonthly cuts. Eight genotypes were evaluated in the plots, and the cutting ages (2, 4, 6, 8, 10, and 12-mo) were analyzed in the subplots. The following traits were assessed: DM yield, (DMY) percentage of DM, and average plant height (HEI). All genetic-statistical analyses were conducted using the Genes Program. The evaluated genotypes showed nonsignificant differences, indicating that, for the evaluated traits, these genotypes are genetically similar. Most genotypes presented linear effect of 2nd degree in the two assessment cuts, pointing they did not reach their maximum capacity of DMY in the time interval of the evaluated cuts. The maximum %DM achieved for the most genotypes occurred at about 9-mo age, while genotypes Vruckwona and BAG-86 at about 10-mo age. The maximum points for HEI trait were between 8 and 10-mo age. Increasing the cutting interval leads to increases in DM yield, with the 10-mo cutting age being the most efficient, resulting in higher yields

Effect of nitrogen and potassium fertilization doses on elephant-grass genotypes for energy purposes.

In view of the current global energy landscape, to develop alternative energy mechanisms to the oil has become essential. For that, biomass as well as the use of elephant-grass present themselves as attractive choices for energy purposes. That culture has a high growth prospect, as it contains characteristics such as high production, biomass quality, and high photosynthetic capacity. The purpose of this work was to assess the response of eight elephant-grass genotypes to nitrogen and potassium fertilization from the evaluation of morpho-agronomic traits. It was used a randomized block experimental design with three replications in the factorial scheme within a subdivided plot composed of principal factor (plots): genotypes and secondary components (subplots): potassium (2 levels) × nitrogen (3 levels)—200 × 400, 200 × 1000, 200 × 1600, 500 × 400, 500 × 1000, and 500 × 1600 kg ha-1. There was an adjustment of first degree linear model of the regression for all traits in at least one genotype. For DMP, the Capim Cana D’África, CPAC, and IJ 7139 genotypes indicated an inversely proportional response to the increasing of N in the fertilization. The response according to the N increasing in the fertilization was directly proportional for the CPAC genotype in relation to the NP, and for the Cana D’África, CPAC, and IJ 7139 genotypes in relation to the ALT. For SD, the CPAC and Vruckwona genotypes showed a positive effect on the increasing doses of N, and the IJ 7139 genotype, a negative correlation. The results are quite promising and ensure the use of the eight elephant-grass genotypes as an alternative source for biomass production

Estimation of genetic parameters and selection of elephant-grass ( Pennisetum purpureum Schumach.) for forage production using mixed models.

The efficient use of fodder and grassland as the basis of animal feed represents a way of raising productivity and reducing production costs. In this scenario, elephant-grass stands out among the most used forages in the intensive animal production systems in the world mainly due to its high productive potential, support capacity and nutritional quality. The purpose of this work was to estimate genetic parameters for the selection of elephant-grass (Pennisetum purpureum Schumach.) clones for forage production in two seasons, a period of water restriction and the total period of study. We evaluated 80 accessions of elephant-grass by means of the mixed-models methodology (REML/BLUP). The evaluation of DM yield (DMY) of the different genotypes were executed in edaphoclimatic conditions in Campos dos Goytacazes, Rio de Janeiro, Brazil. The Selegen-REML/BLUP software accomplished the statistical and genetic analyses. It was seen that the DMY trait was with a low estimate of coefficient of genotypic variation (3.08%), which demonstrates possible difficulties with the selection for this trait. Heritability-coefficient estimate was 0.3606 for the dry season and 0.4193 for the total period. Those results were the variation in that trait due to genetic causes. Although those values may not be considered of high magnitude, they are of great interest for the breeding mainly because it is a polygenic trait. In both periods, genotypes 7, 25, 41, 43, 57, 58, 62, 64, 68, and 77 stood out among the others, since it presented the highest genetic gains for DMY, which will enhance progress in the evaluated trait.Made available in DSpace on 2018-12-13T00:07:50Z (GMT). No. of bitstreams: 1 Cnpgl2018ChileanJarVanderEstimation.pdf: 206918 bytes, checksum: 37c3fbdb493be83a0bce3494149dae45 (MD5) Previous issue date: 2018-12-12bitstream/item/188216/1/Cnpgl-2018-ChileanJar-Vander-Estimation.pd

Screening of elephant grass genotypes following some agro-marphological traits related to biomass production in Rio de Janeiro (Brazil).

The purpose of this research was to evaluate the behavior per se of elephant grass (Pennisetum purpureum Shum) hybrids for energy purposes by means of morpho-agronomic traits in four evaluation sections. An experiment in randomized block design with three replicates was applied to evaluate the hybrids. The plot consisted of a 15-m row with 1.50-m row spacing, and 1.50-m spacing between plants. The usable area was composed of the five central plants. It was evaluated number of tillers per clump; Stem dry matter. Computational resources from the GENES Program were used to analyze the results. In both cuts, the H7, H11, and H14 hybrids was superior to the others in the four evaluation cuts for all evaluated characteristics, proving to be a potential genotype to be used for energy biomass production.Made available in DSpace on 2019-08-17T00:40:22Z (GMT). No. of bitstreams: 1 Screeningelephant.pdf: 554321 bytes, checksum: 5b0333bdb5d5833e95f3fde717ab1073 (MD5) Previous issue date: 2019bitstream/item/200987/1/Screening-elephant.pdfArticle nº JEAI.50113

Estimation of repeatability and genotypic superiority of elephant grass half-sib families for energy purposes using mixed models.

The mixed-model methodology is an alternative to select genotypes for traits highly influenced by the environment. In addition, this method allows FOR estimating the repeatability coefficient and predicting the number of assessments needed for a selection process to increase reliability. This study aimed to determine the minimum number of evaluations necessary for a reliable selection process and to estimate the variance components used for predicting genetic gains between and within half-sib families of elephant grass (Cenchrus purpureus (Schumach.) Morrone) using the mixed-model methodology. Half-sib families were generated using genotypes from the Active Germplasm Bank of Elephant Grass. The experiment was performed in a randomized block design with nine half-sib families, three replicates, and eight plants per plot. We evaluated 216 genotypes (individual plants) of elephant grass. The deviance analysis was carried out, genetic parameters were estimated, gains between and within families were predicted, and repeatability coefficients were obtained using Selegen software. There was genetic variability for selection within the families evaluated. The reliability values found above 60 % for plant height and number of tillers and above 80 % for dry matter yield suggest that only two evaluations are required to select superior genotypes with outstanding reliability. Sixteen genotypes were identified and selected for their productive potential, which can be used as parents in elephant grass breeding programs for bioenergy production