Sweet Sorghum Genotypes Research Articles

Genetic divergence between sweet sorghum genotypes by the WARD-MLM procedure

Genetic divergence between sweet sorghum genotypes by the WARD-MLM procedure

Productivity of Sweet Sorghum Genotypes under Contrasting Fertility Management for Food and Ethanol Production

Sweet sorghum (Sorghum bicolor (L.) Moench) has a good potential for ethanol production in Ethiopia. However, continual supply of feed stock to the distillery is one of the major constraints in sweet sorghum-based ethanol and grain yield productions. A study was carried out in Ethiopia during the 2015 to 2016 crop seasons to determine the performance of sweet sorghum genotypes for their stability or specific adaptability under contrasting fertilizer rates across environments. All agronomic characters were varied with the genotypes and environments. Grain yield, panicle weight and plant height were also significantly varied with fertilizations, but other agronomic characters were not varied with fertilizations. The ethanol yield and quality components varied with genotypes, environments and fertilizations, but brix % was not varied with fertilizations. The genotypes, E36-1, ICSR 93034 and IESV 92207 DL, produced greater estimated sugar, ethanol, juice and fresh stalk yield. The genotype, IESV 92207 DL, was the superior genotypes in grain yield and yield related traits, although it was second in brix % and ethanol yield followed by E36-1. At phenotypic and genotypic levels, grain yield was positive and significant correlations with panicle weight and panicle width. There was positive and significant (p<0.01) correlations between ethanol, juice, sugar and fresh stalk yields at both levels, this indicates the merits of these quality characters to improve ethanol yield.

Callus Induction and Plant Regeneration from Immature Embryos of Sweet Sorghum (Sorghum bicolor Moench).

Background and ObjectiveRegeneration of plant through tissue culture technique is a critical process in transformation of plants. This study sought to establish the effect of genotype and auxin concentration on callus induction from different sweet sorghum genotypes (IESV92008DL, IESV92001DL, IESV92021DL, ICSV700 and ICSV93048).Materials and MethodsIn this study, MS medium supplemented with five levels of the hormone 2,4-D (0, 1, 2, 4 and 6 mg L-1) to assess the effect of the hormone 2,4-D on callus induction and regeneration was used.ResultsThe highest callus induction frequency was observed at 2 mg L-1 2,4-D for all the genotypes, IESV92008 gave the highest callus induction frequency among all the genotypes at 2 mg L-1 2,4-D. The lowest callus induction frequency was observed 0 and 6 mg L-1 for all the genotypes, the two genotypes ICSV700 and IESV92021 were observed to give the lowest callus induction frequency among all the genotypes used in this study. Embryogenic callus induction frequency was observed to be higher at 2 mg L-1 2,4-D and the genotype IESV92008 gave the highest callus induction frequency among all the genotypes used. Induction of shoots was achieved in MS medium supplemented with 3 mg L-1 6BA and 1 mg L-1 IAA, the highest regeneration efficiency was obtained from the three genotypes ICSV93048, IESV92008 and IESV92001, respectively.ConclusionThis study discovers the importance of the auxin 2,4-D on callus induction and regeneration of sweet sorghum and this will help the researcher to develop protocols for transformation of sweet sorghum.

Characterisation of ten commercial sorghum genotypes grown under water-limited conditions for bioenergy production in Mediterranean environment

The evaluation of commercial hybrids under limited water availability is of primary importance to assess Sorghum bicolor (Moench) as potential multipurpose bioenergy crop in Mediterranean drought prone environments. Ten genotypes were grown during three growing seasons (2010, 2011 and 2012) in open field trials and in pot experiments (2014). Phenological traits, biomass production, fibre content and biomass chemical composition were measured under irrigated and rainfed conditions. Differences in biomass production among the ten genotypes varied across years. In a three-year experiment significant differences were found among the ten genotypes in terms of duration of vegetative growth (P&lt;0.05) and aboveground dry biomass production (P&lt;0.1) in response to irrigated and rainfed conditions. Among the ten genotypes analysed, the hybrid ABF306 stands for its performance in terms of biomass production and chemical composition. In fact, it showed the lowest biomass yield reduction when grown under rainfed conditions, the highest drought tolerance index (=0.9), a °Brix value comparable to that of sweet sorghum genotypes (8.8 °Brix under rainfed conditions), lignin content that was not statistically influenced by water availability, and a lignin cellulose ratio (0.087) favourable for biogas production. The shoot transpiration efficiency and the total transpiration efficiency recorded at high (Exp1) and low (Exp2) vapour pressure deficit were comparable, and sometimes higher, to that of commercial sorghum hybrids. All these characteristics make ABF306 a suitable candidate for bioenergy production in Mediterranean drought prone environments.

English

Sweet sorghum is considered one of the best sources of bioethanol due to its higher total reducing sugar content, which ferments completely to produce ethanol coupled with its adaptation to the changing climate. A study was carried out in Ethiopia, during the 2015/16 crop season, to determine the extent of phenotypic and genotypic relationships among 13 agronomic traits and six quality components of 28 sweet sorghum genotypes. Panicle weight and width, dry matter yield, thousand kernel weight and harvest index had significant positive correlation with grain yield and exerted favourable direct effects both at phenotypic and genotypic levels. Ethanol yield was also correlated with juice yield, sugar yield and fresh stalk yield. Therefore, these yield and quality components are suggested to receive due attention during sweet sorghum varietal selection. Moreover, days to maturity had negative correlation and imposed negative direct effect on grain yield, which may indicate the possibility to select high yielding, early maturing dual purpose varieties for dry environments where terminal drought is rampant. The studied genotypes were grouped into three clusters according to their D2 values, worthy of future breeding work considering the special merits in each cluster depending on the objectives of the breeding program. Some of the genotypes excelled as one of the two commercial sugarcane varieties used as controls for some quality traits. Therefore, considering their less water requirement, faster production cycle, and additional advantage of grain production over sugarcane, sweet sorghum stalks can serve as alternatives to sugarcane for use as feedstock in drier areas of the world under the changing climate. Key words: Bioethanol, correlation, juice, path-coefficient, sweet sorghum.

Characterisation of sweet stem sorghum genotypes for bio-ethanol production

ABSTRACTIn an effort to characterise and select promising sweet stem sorghum genotypes with enhanced biofuel productivity, the present study investigated phenotypic variability present among diverse sweet stem sorghum genotypes based on ethanol production and related agronomic traits. One hundred and ninety genotypes were evaluated. Data were subjected to variance, cluster, correlation, path coefficient and principal component analyses. Significant differences (P < 0.01) were detected among tested genotypes for all measured traits. Days to flowering varied from 62 to 152 with a mean of 93. Plant height varied from 90 to 420 cm with a mean of 236 cm. Stem diameter ranged from 7 to 31 mm with a mean of 16 mm. Biomass yield varied from 6.668 to 111.2 t ha−1 with a mean of 30 t ha−1. Stalk dry matter content ranged from 17.2% to 44.2% with a mean of 29.8%, while fibre content varied from 8.92% to 34.8% with a mean of 17.2%. The stalk brix yield varied from 3.3% to 18.9% with a mean of 12.1%. Ethanol productivity ranged from 240.9 to 5500 l ha−1 with a mean of 1886 l ha−1. The best ethanol producing genotypes were AS203, AS391, AS205, AS251 and AS448. Days to flowering, plant height, stalk brix and stem diameter exerted the greatest indirect effects on ethanol production through higher biomass production. Biomass yield had the greatest direct effect on ethanol production. Therefore, the above traits should be considered during breeding sorghum for bio-ethanol production. Also, the traits had high heritability values, hence selection should provide for good genetic gains. Overall, the above sweet stem sorghum genotypes are useful genetic resources for breeding of sorghum with enhanced bio-ethanol production.

Características agronómicas asociadas a la producción de bioetanol en genotipos de sorgo dulce

Energy production from sorghum bioethanol is a way to help decrease climate change and environmental degradation. The objective of this work was to evaluate the agronomic characteristics associated to bioethanol production in experimental genotypes of sweet sorghum. During 2013 and 2014, seventeen sweet genotypes were evaluated in two locations, this locations are situated in northeastern Mexico, under a complete block randomly design with three replications. The three experiments were executed in Estacion Cuauhtemoc, Tamaulipas, in dryland; and two in Marin, Nuevo León, under irrigation. Experimental hybrid Potranca x Keller (p≤0.05) presented the highest values (kg/ha) in: biomass weight (52 125), stem (39 650), panicle (4550), leaf (7700), juice (14 125), and bioethanol (2157 l/ha); it surpassed to the most productive control (Keller) in: 35,7, 32,5, 63,2, 41,6, 32,5, and 36,8%, respectively. It bloomed 6.8 days earlier than variety control. Experimental variety 17-1-1-1 had a minor foliar incidence of diseases in comparison to Keller. In addition, it presented agronomic characteristics similar to control in: biomass weight (44 375 kg/ha), stem (35 438 kg/ha), panicle (2488 kg/ha), leaf (6400 kg/ha), juice (11 750 kg/ha), plant dry weight (19 113 kg/ha), stem dry weight (14 888 kg/ha), bioethanol production (1929 l/ha), °Brix (15,2), days to flowering (80,8) and plant height (224 cm).

Comparative transcriptome combined with morpho‐physiological analyses revealed key factors for differential cadmium accumulation in two contrasting sweet sorghum genotypes

SummaryCadmium (Cd) is a widespread soil contaminant threatening human health. As an ideal energy plant, sweet sorghum (Sorghum bicolor (L.) Moench) has great potential in phytoremediation of Cd‐polluted soils, although the molecular mechanisms are largely unknown. In this study, key factors responsible for differential Cd accumulation between two contrasting sweet sorghum genotypes (high‐Cd accumulation one H18, and low‐Cd accumulation one L69) were investigated. H18 exhibited a much higher ability of Cd uptake and translocation than L69. Furthermore, Cd uptake through symplasmic pathway and Cd concentrations in xylem sap were both higher in H18 than those in L69. Root anatomy observation found the endodermal apoplasmic barriers were much stronger in L69, which may restrict the Cd loading into xylem. The molecular mechanisms underlying these morpho‐physiological traits were further dissected by comparative transcriptome analysis. Many genes involved in cell wall modification and heavy metal transport were found to be Cd‐responsive DEGs and/or DEGs between these two genotypes. KEGG pathway analysis found phenylpropanoid biosynthesis pathway was over‐represented, indicating this pathway may play important roles in differential Cd accumulation between two genotypes. Based on these results, a schematic representation of main processes involved in differential Cd uptake and translocation in H18 and L69 is proposed, which suggests that higher Cd accumulation in H18 depends on a multilevel coordination of efficient Cd uptake and transport, including efficient root uptake and xylem loading, less root cell wall binding, and weaker endodermal apoplasmic barriers.

Crop Factors Influencing Ethanol Production from Sorghum Juice and Bagasse

This study investigated the effects of two soil moisture levels (SM) (30% and 70% soil available water) and three harvests (90 days, 118 days, and 151 days after seeding) on sweet (S506) and fiber (B133) sorghum genotypes under rain-sheltered conditions. Juice and bagasse-derived ethanol and their sum (EtOHBJ, EtOHB, and EtOHJ+B, respectively) were assessed. Water use efficiency (WUE) was determined for sorghum dry weight (DW) and EtOHJ+B. S506 had similar DW, but higher sugar content than B133, resulting in higher EtOHJ (+32%) and EtOHJ+B (+9%). High SM-enhanced DW, juice and sugars content, determining a strong EtOHJ+B increase (+99% vs. low SM). Late harvest enhanced DW and EtOHJ+B (+107% vs. early harvest), despite decreasing extractives and increasing structural fiber components. Water use efficiency of EtOHJ+B improved with high vs. low SM, although differences faded in late harvest. Upscale of EtOHJ+B and WUE data indicated a range of 21,000–82,000 ha of sorghum cultivation and 60–117 Mm3 of irrigation water, as amounts of resources needed to supply an 85,000 m3·yr−1 bio-ethanol plant. This large variation in land and water needs depended on specific combinations between crop factors SM and harvests.

Near infrared spectroscopy determination of sucrose, glucose and fructose in sweet sorghum juice

Sweet sorghum is a very robust crop which has the potential to be used in ethanol production due to its high fermentable sugar content present in its stem juice, very similar to sugarcane. Therefore, for breeding purposes it is relevant to analyze sugar composition in the juice to characterize sweet sorghum genotypes and their period of industrial utilization within different environments for maximum ethanol yield. In this work we developed a rapid, low cost and efficient method to determine the profile of sugars (sucrose, glucose and fructose) in sorghum juice by near infrared spectroscopy and partial least square regression, and validation of the method was performed according to the high-performance liquid chromatography method. Developed models provided root mean square error of prediction of 4, 1 and 0.6mg·mL−1 and ratio performance deviations of 8, 5 and 5 for sucrose, glucose and fructose, respectively. Relative standard deviations of three sweet sorghum juice samples were reported with content variation (low, medium and high) 0.2, 0.3, 0.8% for sucrose; 1, 2, 2% for glucose; 1, 2, 3% for fructose. Sugar profile is an asset for crop breeders to take decisions for the development of more productive cultivars and higher sugar content.

Contribution of a mixed inoculant containing strains of Burkholderia spp. and Herbaspirillum ssp. to the growth of three sorghum genotypes under increased nitrogen fertilization levels

Sorghum bicolor is a C4 plant that is normally associated with diazotrophs. Inoculation with selected bacteria can improve plant growth, biological nitrogen fixation (BNF) and nutrient uptake. Therefore, the objective of the current study was to evaluate the ability of twenty-two diazotroph strains to improve sorghum growth in a greenhouse. Then, a mixture of the best performing strains was applied in the field under different levels of N-fertilizer applied to three sorghum genotypes to evaluate crop productivity, N content, BNF contribution and the efficiency of the N fertilizer used under field conditions. Two Herbaspirillum and two Burkholderia species were selected under greenhouse conditions using a sterile substrate of three sorghum genotypes: grain sorghum lineage 9920044, grass BRS655 and sweet sorghum BR501. Four diazotrophs were selected for the field trial. Burkholderia kururiensis (16 and 109), B. tropica (PPe6) and Herbaspirillum seropedicae (ZMS176) were cultivated and mixed at planting in a Typic Hapladult soil using peat inoculant. Crop yield, N-content and BNF quantification were determined using the natural abundance of 15N, and the use efficiency of the applied N was assessed using urea labelled with 15N. The grain yield showed a 24% enhancement in the inoculated grain sorghum compared with the control without nitrogen. In addition, the aerial biomass was 13% higher in the grass genotype compared with the control. The sweet sorghum did not respond to any treatment. BNF quantification reached 31.4% in the grain, 22.7% in the grass and 19.4% in the sweet sorghum genotypes. Grain sorghum inoculation increased BNF by 4% (9.5kgha−1N fixed). Inoculation increased fertilizer efficiency recovery by 28.9%. Inoculation using a mixture containing the four diazotrophs improved the sorghum productivity by enhancing the dry mass, N-content, N from BNF and N use efficiency in the grain and grass genotypes. Under zero nitrogen fertilizer application, 22% of the N that accumulated in the biomass was derived from the air. New inoculants using a mixture of different bacterial species/strains can improve the knowledge and contribution of BNF in agricultural systems.

Effect of Harvesting Stage on Sweet Sorghum (Sorghum bicolor L.) Genotypes in Western Kenya.

Harvesting stage of sweet sorghum (Sorghum bicolor L. Moench) cane is an important aspect in the content of sugar for production of industrial alcohol. Four sweet sorghum genotypes were evaluated for harvesting stage in a randomized complete block design. In order to determine sorghum harvest growth stage for bioethanol production, sorghum canes were harvested at intervals of seven days after anthesis. The genotypes were evaluated at different stages of development for maximum production of bioethanol from flowering to physiological maturity. The canes were crushed and juice fermented to produce ethanol. Measurements of chlorophyll were taken at various stages as well as panicles from the harvested canes. Dried kernels at 14% moisture content were also weighed at various stages. Chlorophyll, grain weight, absolute ethanol volume, juice volume, cane yield, and brix showed significant (p = 0.05) differences for genotypes as well as the stages of harvesting. Results from this study showed that harvesting sweet sorghum at stages IV and V (104 to 117 days after planting) would be appropriate for production of kernels and ethanol. EUSS10 has the highest ethanol potential (1062.78 l ha−1) due to excellent juice volume (22976.9 l ha−1) and EUSS11 (985.26 l ha−1) due to its high brix (16.21).

Genetic transformation and evaluation of two sweet sorghum genotypes for resistance to spotted stemborer, Chilo partellus (Swinhoe)

Sweet sorghum is a climate smart crop with multiple uses. The crop is susceptible to attack by the spotted stemborer, Chilo partellus (Swinhoe). This causes deadheart formation, leading to lodging of plants and consequent high economic losses. Lack of stable sources of resistance make any genetic enhancement through breeding difficult. We report a study to build up host plant resistance using transgenic technology by introducing two different classes of Bt genes (cry1Aa and cry1B) into two elite sweet sorghum genotypes of India (SSV84 and RSSV9). We devised tissue culture methods to suit the genotypes of our interest, SSV84 and RSSV9, and employed two methods of genetic transformation: the particle bombardment and in planta method of Agrobacterium. Modification of in vitro culture methods involved subculture every 3 days in the initial stages of culture and the use of precultured embryos as target tissues. For the in planta method, a floral dip for 1 h in Agrobacterium suspension supplemented with l-cysteine and Tween-20 was used. Sixteen transgenic events were generated; inheritance, integration and stable expression of the transgenes till the T4 generation were confirmed. The amount of Bt Cry1Aa protein at 25–30 days of growth ranged from 24.8 to 72.8 ng/g of fresh leaf tissue. We recorded 78.4 % larval mortality, reduced leaf damage (3.0 out of 9.0) and reduced feeding (41.0 %) over the controls in insect feed assays. Stable inheritance and expression in the in planta-derived transgenics are presented.

Nitrogen response of sweet sorghum genotypes during rainy season

Sweet sorghum ( Sorghum bicolor (L.) Moench) is a smart biofuel crop, which can be grown under tropical rainfed conditions without sacrificing food and fodder security. Three sweet sorghum cultivars (viz. ICSA 52 × SPV 1411, CSH 22 SS and ICSV 93046) were grown under six nitrogen levels (0, 30, 60, 90, 120, 150 kg ha -1 ) on Vertisols during two rainy ( kharif ) seasons at ICRISAT, Patancheru, India. The results from two-year trial indicated that out of three sweet sorghum cultivars evaluated, sweet sorghum hybrid CSH 22 SS produced highest green stalk (46.90 t ha -1 ) and ethanol yield (1940 l ha -1 ) compared to other cultivars. The three cultivars responded well to applied N doses up to 150 kg ha -1 , however, application of N beyond 90 kg ha -1 did not result in any significant increase in grain yield and economic returns. Net economic returns of Rs 32,898 ha -1 (US$ 601.21 ha -1 ) were significantly higher with 90 kg N ha -1 application as compared to other levels of fertilization. It is concluded that for obtaining the highest green stalk yield, ethanol yield and thereby maximum economic returns, sweet sorghum cultivar, viz. CSH 22 SS should be fertilized with 90 kg N ha -1 .

Molecular evaluation of Ethiopian sweet sorghum germplasm and their contribution to regional breeding programs

Sweet sorghum is an excellent feedstock for ethanol production and is also used for food and livestock feed. Germplasm collection and characterization in sweet sorghum is a crucial step towards breeding and development of superior genotypes for various end-uses. In the present study, 13 Simple Sequence Repeat (SSR) markers were used for genotyping 175 Ethiopian sweet sorghum genotypes alongside 27 improved accessions from eastern and southern Africa. All the tested markers detected 159 alleles and a high degree of polymorphism information content (PIC) averaging 0.69. A comparison between Ethiopian and improved accessions revealed higher allele numbers (124) in Ethiopian than improved accessions (92 alleles). More than half (65 out of 124) of the alleles observed in the Ethiopian accessions were rare (<5%) and 64 were private (only present within Ethiopian accessions) while in the improved accessions, 41% and 38% of the alleles detected were rare and private respectively. Both weighted Neighbor Joining-based clustering and hierarchical clustering grouped the 202 accessions into three major clusters based on geographical origin. Ethiopian accessions from the north (north Wello and south Tigray) not only clustered separately from accessions from the west central and eastern Ethiopia, but were also distinct from most of the improved genotypes. Our results reveal an unexploited highly diverse sweet sorghum genetic resource from Ethiopia that can be included in the regional breeding programs in order to efficiently optimize productivity.

English

Genotype x environment interaction was determined from field experiments conducted to evaluate sweet sorghum genotypes in Western Kenya during the 2011, 2012 and 2013 rainy season from April to July at Alupe, Kibos, Homa Bay and Spectre International farm. The materials used in the study consisted of sixteen sweet sorghum genotypes and two sorghum genotypes sourced from ICRISAT and KARI. The treatments were laid out in a Randomized Complete Block Design (RCBD) and replicated three times. Data were collected on sorghum traits in accordance with the procedure outlined in the ICRISAT sorghum descriptor. The study revealed that genotype by environment interaction had significant influence on most of the traits. This indicates that selection for plant height, girth, brix juice, juice volume and stalks weigh cannot be carried out across the four environments, suggesting that selection for these traits have to be carried separately in each of the four environments. &nbsp; Key words: Biomass, brix, environment, genotype, sweet sorghum.

Three FLOWERING LOCUS T-like genes function as potential florigens and mediate photoperiod response in sorghum.

Sorghum is a typical short-day (SD) plant and its use in grain or biomass production in temperate regions depends on its flowering time control, but the underlying molecular mechanism of floral transition in sorghum is poorly understood. Here we characterized sorghum FLOWERING LOCUS T (SbFT) genes to establish a molecular road map for mechanistic understanding. Out of 19 PEBP genes, SbFT1, SbFT8 and SbFT10 were identified as potential candidates for encoding florigens using multiple approaches. Phylogenetic analysis revealed that SbFT1 clusters with the rice Hd3a subclade, while SbFT8 and SbFT10 cluster with the maize ZCN8 subclade. These three genes are expressed in the leaf at the floral transition initiation stage, expressed early in grain sorghum genotypes but late in sweet and forage sorghum genotypes, induced by SD treatment in photoperiod-sensitive genotypes, cooperatively repressed by the classical sorghum maturity loci, interact with sorghum 14-3-3 proteins and activate flowering in transgenic Arabidopsis plants, suggesting florigenic potential in sorghum. SD induction of these three genes in sensitive genotypes is fully reversed by 1 wk of long-day treatment, and yet, some aspects of the SD treatment may still make a small contribution to flowering in long days, indicating a complex photoperiod response mediated by SbFT genes.

Adaptability and Stability Study of Selected Sweet Sorghum Genotypes for Ethanol Production under Different Environments Using AMMI Analysis and GGE Biplots.

The genotype and environment interaction influences the selection criteria of sorghum (Sorghum bicolor) genotypes. Eight sweet sorghum genotypes were evaluated at five different locations in two growing seasons of 2014. The aim was to determine the interaction between genotype and environment on cane, juice, and ethanol yield and to identify best genotypes for bioethanol production in Kenya. The experiments were conducted in a randomized complete block design replicated three times. Sorghum canes were harvested at hard dough stage of grain development and passed through rollers to obtain juice that was then fermented to obtain ethanol. Cane, juice, and ethanol yield was analyzed using the additive main effect and multiplication interaction model (AMMI) and genotype plus genotype by environment (GGE) biplot. The combined analysis of variance of cane and juice yield of sorghum genotypes showed that sweet sorghum genotypes were significantly (P < 0.05) affected by environments (E), genotypes (G) and genotype by environment interaction (GEI). GGE biplot showed high yielding genotypes EUSS10, ACFC003/12, SS14, and EUSS11 for cane yield; EUSS10, EUSS11, and SS14 for juice yield; and EUSS10, SS04, SS14, and ACFC003/12 for ethanol yield. Genotype SS14 showed high general adaptability for cane, juice, and ethanol yield.

Influence of late planting on light interception, radiation use efficiency and biomass production of four sweet sorghum cultivars

As a measure of a plants ability to convert solar energy into biomass, radiation use efficiency (RUE) can be used to compare species and genotypes within species. Despite considerable research on RUE of biofuel species, few reports on sweet sorghum (Sorghum bicolor (L.) Moench.) RUE are available. Radiation use efficiency and biomass yield of four sweet sorghum genotypes (‘Dale’, ‘M 81E’, ‘Topper 76-6’, and ‘Sugar Drip’) was assessed in response to two late planting dates in a two-year study. The late planting dates would coincide with abandoning double-crop plantings of soybean following wheat. Aboveground biomass yield and RUE (gbiomassMJ−1 intercepted photosynthetically active radiation (IPAR)) was measured every two weeks beginning four weeks after planting. Two estimates of RUE were calculated differing only in growth periods used (emergence to anthesis [EA] and during rapid linear growth [Max]). Biomass yields, EA, and Max RUE were similar between years and sorghum cultivars, but differed between planting dates. Early-July plantings resulted in greater RUE than mid-July plantings. Averaged across cultivars at the first planting date both years EA and Max RUE were 3.11 and 3.96gMJ−1IPAR, respectively, compared to 2.40 (EA RUE) and 2.79gMJ−1IPAR (Max RUE) at the second planting date. Mean biomass yield across years and cultivars was 10.67 and 8.63Mgha−1 at the first and second planting dates, respectively. These results confirm expected decreases in RUE and biomass production of late-planted sweet sorghum, but also illustrate that, even when planted late, sweet sorghum efficiently converts intercepted PAR to biomass.

Sweet Sorghum Genotypes Testing in the High Latitude Rainfed Steppes of the Northern Kazakhstan (for Feed and Biofuel)

Twenty-eight sweet sorghum (Sorghum bicolor (L.) Moench) genotypes of the different ecological and geographic origins: Kazakhstan, Russia, India, Uzbekistan, and China were tested in the high latitude rainfed conditions of northern Kazakhstan. The genotypes demonstrated high biomass production (up to 100 t·ha-1 and more). The genotypes ripening to full reproductive seeds were selected for seed production and introduction in the northern Kazakhstan. Lactic acid bacteria Lactobacillus plantarum S-1, Streptococcus thermophilus F-1 and Lactococcus lactis F-4 essentially enhance the fermentation process, suppressing undesirable microbiological processes, reducing the loss of nutrient compounds, accelerating in 2 times maturation ensilage process and providing higher quality of the feed product.