Utilization of whole sorghum crop residues for bioethanol production

Sorghum is the fifth most important cereal worldwide and is a major source of agricultural residues in tropical regions. Bioconversion of whole sorghum crop residues comprising stalks, leaves, peduncles and panicles to ethanol has great potential for improving ethanol yield per sorghum crop cultivated, and for sustainable biofuel production. Effective pretreatment of sorghum lignocellulosic biomass is central to the efficiency of subsequent fermentation to ethanol. Previous studies have focused on bioconversion of sorghum stalks and/or leaves only to bioethanol, but the current study is the first report dealing with whole crop residues. We specifically focused on the impact of Nigerian sorghum cultivation location and cultivar type on the potential ethanol yield from whole sorghum crop residues. Efficient bioconversion of whole sorghum residues to ethanol provides a sustainable route for utilisation of crop residues thereby providing a non-food feedstock for industrial scale bioethanol production

Sweet sorghum:agronomic practice for food, animal feed and fuel production in Sub-Saharan Africa

Sweet sorghum is a cereal that belongs to the species Sorghum bicolor (L) Moench. Although the crop is reportedly native to Africa, it is grown worldwide largely because it thrives well under wide rainfall regimes, varied day lengths, soil conditions and can tolerate varying degrees of biotic and abiotic factors and stresses. This chapter reviews and discusses the physiology and adaptation of sweet sorghum crops to varied environmental and climatic conditions across Sub-Saharan Africa. Several research works have indicated that numerous improved cultivar types of sweet sorghum are grown across Africa. Virtually all sweet sorghum cultivars are primarily grown to produce grain, sugary stalk juice and forage or fodder. The grains are considered the 3rd most important source of staple food to people living in the Sub-Saharan Africa region. Furthermore, the grains may also be malted to produce beverages or utilized as adjunct in beer brewing. However, the sugary stalk juice is most commonly used for sorghum molasses or syrup production. Sorghum molasses or syrup is a suitable alternative to refined cane sugars for beverage consumption; particularly for diabetic patients. Thus, the nutritional value, health benefits and future prospects of sorghum grain consumption to address certain human health challenges are discussed in this chapter. Alternatively, the sugary stalk juice from sorghum may be bio-converted to bioethanol (a fuel alcohol). Sweet sorghum crop residues (i.e., leftovers and after the grains are harvested and stalk juice extracted) can serve as animal feed or utilized as lignocellulosic biomass for second generation bioethanol production. This chapter reviews and discusses literature that demonstrates sweet sorghum is a cereal crop with high tolerance to diverse environmental and climatic conditions. In addition, the crop produces nutritious grains and sugary stalk juice that are of important health and economic benefits for domestic and industrial applications throughout in Africa

Factors affecting sorghum protein digestibility

In the semi-arid tropics worldwide, sorghum (Sorghum bicolor (L.) Moench) is cultivated by farmers on a subsistence level and consumed as food by humans. A nutritional limitation to its use is the poor digestibility of sorghum protein when wet cooked. The factors affecting wet cooked sorghum protein digestibility may be categorised into two main groups: exogenous factors (grain organisational structure, polyphenols, phytic acid, starch and non-starch polysaccharides) and endogenous factors (disulphide and non-disulphide crosslinking, kafirin hydrophobicity and changes in protein secondary structure). All these factors have been shown to influence sorghum protein digestibility. More than one factor may be at play at any time depending on the nature or the state in which the sorghum grain is; that is whether whole grain, endosperm, protein body preparation, high-tannin or condensed-tannin-free. It is proposed that protein crosslinking may be the greatest factor that influences sorghum protein digestibility. This may be between ?- and ß-kafirin proteins at the protein body periphery, which may impede digestion of the centrally located major storage protein, a-kafirin, or between ?- or ß-kafirin and a-kafiri

Effects of total replacement of corn silage with sorghum silage on milk yield, composition, and quality

BACKGROUND: In the last years, difficulties occurring in corn cultivation (i.e., groundwater shortages, mycotoxin contamination) have been forcing dairy farmers to consider alternative silages. Some experiments conducted on lactating cows have proven that the total replacement of corn silage with sorghum silage did not reduce milk yield. However, this kind of substitution involves supplementing sorghum-based diets with grains, to compensate for the lower starch content of sorghum silage compared to corn silage. Change of silage type and inclusion of starch sources in the diet would influence rumen fermentations, with possible effects on milk composition (i.e., fatty acid profile) and coagulation properties. A worsening of milk coagulation properties would have a negative economic impact in Italy, where most of the milk produced is processed into cheese. This study was designed to compare milk composition and quality, with emphasis on fatty acid profile and coagulation properties, in dairy cows fed two diets based on corn or sorghum silage. RESULTS: The sorghum diet reduced milk yield (P = 0.043) but not 4% fat corrected milk (P = 0.85). Feeding sorghum silage did not influence milk contents of protein (P = 0.07) and lactose (P = 0.65), and increased fat content (P = 0.024). No differences emerged for milk concentrations of saturated (P = 0.61) and monounsaturated fatty acids (P = 0.50), whereas polyunsaturated fatty acids were lower (P < 0.001) for the sorghum diet. Concentrations of n-6 (P < 0.001) and n-3 fatty acids (P = 0.017) were lower in milk of cows fed the sorghum diet. Milk coagulation properties did not differ between the two diets, except the “a30” (the curd firmness, expressed in mm, 30 min after rennet addition), that was lower (P = 0.042) for the sorghum diet. CONCLUSIONS: Feeding a forage sorghum silage, properly supplemented with corn meal, as total replacement of corn silage maintained milk composition and did not influence negatively milk coagulation properties, which have a great economic relevance for the Italian dairy industry. Thus, silages obtained from forage sorghums could have a potential as substitute of corn silages in dairy cow diets

Fermentation of stalk juices from different Nigerian sorghum cultivars to ethanol

For improved production of ethanol from sorghum stalk juice fermentation, cultivation location and cultivar type are important factors to consider. In the present study, SSV2 and KSV8 sorghum cultivars were cultivated in Kano and Kaduna states in Nigeria that exhibit notably different rain precipitation and diurnal temperatures. The crude stalk juices (without pre-treatment or nutrient supplementation) were extracted from these sorghum samples and fermented with a distiller’s strain of the yeast, Saccharomyces cerevisiae. Sugar consumption and alcohol production were determined by HPLC and GC-MS, respectively. When it was grown in the Kaduna site, SSV2 was identified as the highest yielding sorghum cultivar from which we extracted the maximum levels of extractable sugars (161.50 g l-1 ) that yielded favourable ethanol levels of 80.56 g l-1 following fermentation. Our findings show that relatively colder and wetter cultivation sites are preferred for sorghum stalk juice destined for bioethanol production.<br/

Conserved defense responses between maize and sorghum to Exserohilum turcicum.

BACKGROUND:Exserohilum turcicum is an important pathogen of both sorghum and maize, causing sorghum leaf blight and northern corn leaf blight. Because the same pathogen can infect and cause major losses for two of the most important grain crops, it is an ideal pathosystem to study plant-pathogen evolution and investigate shared resistance mechanisms between the two plant species. To identify sorghum genes involved in the E. turcicum response, we conducted a genome-wide association study (GWAS). RESULTS:Using the sorghum conversion panel evaluated across three environments, we identified a total of 216 significant markers. Based on physical linkage with the significant markers, we detected a total of 113 unique candidate genes, some with known roles in plant defense. Also, we compared maize genes known to play a role in resistance to E. turcicum with the association mapping results and found evidence of genes conferring resistance in both crops, providing evidence of shared resistance between maize and sorghum. CONCLUSIONS:Using a genetics approach, we identified shared genetic regions conferring resistance to E. turcicum in both maize and sorghum. We identified several promising candidate genes for resistance to leaf blight in sorghum, including genes related to R-gene mediated resistance. We present significant advancements in the understanding of host resistance to E. turcicum, which is crucial to reduce losses due to this important pathogen

Silage Quality of Sorghum Harvested at Different Times and Its Combination with Mixed Legumes or Concentrate Evaluated in Vitro

The experiment was designed to evaluate the silage quality of sorghum forage varieties of Citayam and BMR 3.6 strain at different harvesting times and the effectiveness of a legumes addition as a concentrate substitute in sorghum forage silage-based diets on in vitro fermentability using rumen fluid of beef cattle. Experimental design for silage quality was completely randomized design with 2 x 3 factorial, i.e., forage sorghum types (Citayam and BMR 3.6) and time of harvesting the forage sorghum (85, 95, and 105 d). Experimental design for in vitro fermentability and digestibility was randomized block design with 2 x 2 factorial arrangement, i.e. types of ration (with 2 levels i.e., a mixture of legumes and concentrate) and types of sorghum forage silages (with 2 levels i.e., Citayam and BMR 3.6). All silages had a good odor, color, and texture. Silage of sorghum harvested at 105 d had better grades and was selected for in vitro studies. The treatment had no effect on pH and organic matter digestibility. BMR 3.6 based silage had greater values of NH3, total VFA, rumen microbial population, methane, and dry matter digestibility. Substitution of concentrate with a mixture of legumes did not affect fermentability, microbe population and digestibility in the rumen. Silage of sorghum strain BMR 3.6 harvested at 105 d had a very good quality and mixing with legumes could replace concentrate in forage sorghum silage based diet on in vitro fermentability and digestibility using beef cattle rumen fluid

Comparison of Leaf Reflectance of Sorghum Plants Infested by Sugarcane Aphids

Sugarcane aphid, Melanaphis sacchari (Homiptera: Aphididae; Fig. 1A), is a significant pest to sorghum, Sorghum bicolor (Fig. 1B). Sorghum fields are regularly surveyed to detect pest infestation. Remote sensing methods using satellite and aircraft data are expected to provide an efficient alternative to field surveys. However, spectral signature of sugarcane aphid infested sorghum plants is not well understood. We evaluated reflectance spectra of sorghum leaves infested by sugarcane aphids. We used those spectral data to estimate indices that are related to photosynthetic pigments such as chlorophyll', anthocyanin, and carotenoids. We also estimated an aphid index, damage sensitive spectral index (DSSI)". We used these data to examine whether indices differ between pest infested and uninfested plants. We predicted that plants infested by aphid will have higher levels of anthocyanin, carotenoids, and DSSI indices compared to the control plants. In contrary, chlorophyll index will be greater for uninfested plants

Production Profitability of Ethanol from Alternative Feedstocks in the Texas Panhandle

The potential of three feedstocks: grain sorghum, sweet sorghum, and switchgrass for ethanol production in the top 26 counties of the Texas Panhandle Region is analyzed using yield and production costs of feedstock, processing cost of feedstock, final demand for ethanol, farm to wholesale marketing margin, and the derived demand price of feedstock. The calculated economic returns per acre of grain sorghum, sweet sorghum, and switchgrass are -$45.37, -$410.19, and -$150.17 respectively under irrigated condition and -$38.25, -$145.09, and -$29.04 respectively under dryland condition. The evaluation in this study demonstrates that ethanol production from grain sorghum, sweet sorghum, and switchgrass in the Texas Panhandle Region is not economically feasible given the current price for ethanol in Texas. This is consistent with the status of the ethanol industry in the Texas Panhandle.Ethanol production, Texas Panhandle, Grain sorghum, Sweet sorghum, and Switchgrass, Feedstock, Crop Production/Industries, Production Economics, Resource /Energy Economics and Policy, Q16, Q25, Q27, and Q42,

Consumer Perception of Sorghum Variety Attributes in the Lake Zone Tanzania

Many sorghum varieties have been developed by research institutes in an effort to address food security problems in the semi-arid areas of Tanzania. Although sorghum is better adapted to drier areas than maize, farmer adoption rates for sorghum varieties are always lower than that of maize. In addition, maize based food is more acceptable to urban consumers than sorghum based food. In this study consumer evaluated quality attributes of sorghum ugali based on different varieties in order to determine marketing potential relating to the different improved sorghum varieties. A total of 231 consumers, randomly selected from urban and rural areas participated in a food panel to evaluate ugali prepared from five sorghum varieties (three improved, two local). Conjoint analysis was used to determine consumer perceptions of the variety attributes, while a logistic model was applied to determine preference ranking of different varieties. The results indicated that the color and taste of sorghum ugali were the most important criteria used by consumers to evaluate the quality ugali. The study results indicated that sorghum ugali with white/khaki color and the majority of panel participants preferred neutral or slightly sweet taste. Consumers from rural and urban areas accepted two improved varieties; only consumers from rural areas accepted the remaining variety.Adoption, consumer perception, conjoint analysis, sorghum varieties, Tanzania, Agricultural and Food Policy, Consumer/Household Economics, Demand and Price Analysis, Food Consumption/Nutrition/Food Safety, Food Security and Poverty, Marketing, Productivity Analysis, Research and Development/Tech Change/Emerging Technologies,