Sorghum In Africa Research Articles

Determinants of Adoption of Improved Sorghum Varieties by Small-Scale Farmers in Selected Districts of Western Oromia

Achieving national food security and diversifying export earnings from agricultural products is one of the major challenges currently facing developing countries like Ethiopia. Ethiopia is the largest producer of sorghum in Africa, contributing to ensuring food security in the country. Despite the high production potential and the economic importance of the crop, the adoption, and dissemination of improved sorghum varieties are constrained by various factors. To this end, this study aimed to identify determinants of adoption of improved sorghum varieties in selected districts of Western Oromia Region, Ethiopia with the specific objectives of identifying factors affecting adoption and assessing factors hindering the production of improved sorghum varieties. The study was based on cross-sectional data from 154 randomly selected sorghum-producing farmers. Descriptive and econometric analyses were used to analyze data. The results show that about 14.94% and 85.06% were adopters and non-adopters of the crop respectively. Probit model results showed that education and extension service affected the probability of adoption of improved sorghum varieties positively and significantly while TLU affected it negatively and significantly. Untimely availability of improved seed, Price of seed, Quality of improved seed, unavailability of credit to buy seed, Untimely availability of fertilizer, High price of fertilizer, Access to market information, Low grain price, and Pests and disease are the major constraints that affect sorghum production in the study area. This study suggests the high importance of institutional and government support in education, Extension service, and improved cows than a large number of local breeds. Therefore, policy and development interventions should give emphasis on the improvement of such institutional support systems so as to achieve the adoption practice which increases the production and productivity of small-scale farmers.

CRISPR/Cas9-Mediated Mutagenesis of Carotenoid Cleavage Dioxygenase (CCD) Genes in Sorghum Alters Strigolactone Biosynthesis and Plant Biotic Interactions

Strigolactones are a group of small molecules that play critical roles in plant developmental processes and root biotic interactions. Strigolactones are agronomically important due to their role as a signal for the germination of a parasitic weed ( Striga spp.) that reduces yields of cereal crops worldwide. To identify the genes encoding strigolactones in sorghum and their function, we characterized two CRISPR/Cas9-mediated gene knockouts of carotenoid cleavage dioxygenase 8 ( CCD8) genes ( SbCCD8a and SbCCD8b), which have been shown in other plant species to be involved in strigolactone biosynthesis. Although strigolactones are important for the parasitization of sorghum in Africa, the functions of members of the CCD8 family have not been characterized. The impact of the knockouts on strigolactone production, plant growth and development, resistance to the parasitic weed Striga, and the root-associated microbiomes were investigated in this study. The results revealed that knockout of SbCCD8 genes in sorghum significantly reduced orobanchol production and Striga germination. Strigolactone deficiency altered the shoot and root architecture and reduced grain yield of sorghum. The knockout of the SbCCD8b gene significantly affected the rhizosphere bacterial diversity and community composition at sorghum plant grain-fill stage due to the abolition of orobanchol exudation from roots. Reduced amounts of orobanchol in root exudates also influenced root-associated fungal taxa abundance. Our findings provide new insights into potentially sustainable approaches for the recruitment of beneficial microbes and for parasitic weed control through manipulation of strigolactone production in sorghum.

English

Chilo partellus (Swinhoe) is the most important destructive pest of sorghum in Africa which results in complete crop loss. Currently the management strategies rely heavily on chemical insecticides, which do not provide effective control. The uses of bio-pesticides are encouraging over chemical pesticides. The study was carried out to identify effective plant and animal products and optimum concentrations against C. partellus. 7 treatments each at 3 concentrations (2.0, 2.5 and 3.0 g and 1.0, 1.5 and 2.0 ml) were applied on 2nd and/or 3rd instars larvae. The untreated check was used for comparison. The experiment was laid out in a completely randomized design with 3 replications for each concentration. Result revealed among the treatments Milletia ferruginea Hochst seed powder and aqua extract caused the highest (100%) mortality at 3 g and 2.0 ml concentration on the 2nd day. Cow urine and the mixture (M. ferruginea+cow urine) were recorded higher efficacy mean mortality (86.7 and 93.3%) at 3.0 ml concentration within 3 days respectively. Phytolacca dodecandra L. seed powder, aqua extract and the mixture (P. dodecandra+cow urine) showed significantly lower efficacy mean mortality. In conclusion, M. ferruginea powder and aqua extract, cow urine and combination of M. ferruginea with cow urine were identified as good alternatives to chemical pesticides against C. partellus. Key words: Chilo partellus, cow urine, Milletia ferruginea, Phytolacca dodecandra, sorghum.

Diversity of fall armyworm, Spodoptera frugiperda and their gut bacterial community in Kenya.

BackgroundThe invasive fall armyworm, Spodoptera frugiperda (J.E. Smith) is a polyphagous pest that causes widespread damage particularly to maize and sorghum in Africa. The microbiome associated with S. frugiperda could play a role in the insects’ success and adaptability. However, bacterial communities in S. frugiperda remain poorly studied.MethodsWe investigated the composition, abundance and diversity of microbiomes associated with larval and adult specimens of S. frugiperda collected from four maize growing regions in Kenya through high throughput sequencing of the bacterial 16S rRNA gene. The population structure of S. frugiperda in Kenya was assessed through amplification of the mitochondrial cytochrome oxidase subunit I gene.ResultsWe identified Proteobacteria and Firmicutes as the most dominant bacterial phyla and lesser proportions of Bacteroidetes and Actinobacteria. We also observed differences in bacterial microbiome diversity between larvae and adults that are a likely indication that some prominent larval bacterial groups are lost during metamorphosis. However, several bacterial groups were found in both adults and larvae suggesting that they are transmitted across developmental stages. Reads corresponding to several known entomopathogenic bacterial clades as well as the fungal entomopathogen, Metarhizium rileyi, were observed. Mitochondrial DNA haplotyping of the S. frugiperda population in Kenya indicated the presence of both “Rice” and “Corn” strains, with a higher prevalence of the “Rice” strain.

When bitter is better.

Cultivation of high-tannin sorghum in Africa is associated with herbivore threat from red-billed quelea, but also with reduced sensation of bitterness in humans.

Evidence for Sorghum Domestication in Fourth Millennium BC Eastern Sudan: Spikelet Morphology from Ceramic Impressions of the Butana Group

Since the 1970s, the quest for finding the origins of domesticated sorghum in Africa has remained elusive despite the fact that sorghum (Sorghum bicolor (L.) Moench. sensu stricto) is one of the world’s most important cereals. Recognized as originating from wild populations in Africa (Sorghum arundinaceum (Desv.) Stapf), however, the date and cultural context of its domestication has been controversial, with many scholars inferring an early Holocene origin in parallel with better-known cereal domestications. This paper presents firm evidence that the process of domesticating sorghum was present in the far eastern Sahel in the southern Atbai at an archaeological site associated with the Butana Group. Ceramic sherds recovered from excavations undertaken by the Southern Methodist University Butana Project during the 1980s from the largest Butana Group site, KG23, near Kassala, eastern Sudan, were analyzed, and examination of the plant impressions in the pottery revealed diagnostic chaff in which both domesticated and wild sorghum types were identified, thus providing archaeobotanical evidence for the beginnings of cultivation and emergence of domesticated characteristics within sorghum during the fourth millennium BC in eastern Sudan.

Importance of Sorghum Bicolor in African’s Cultures

Importance of Sorghum Bicolor in African’s Cultures Cheick Oumar Kangama Abstract Sorghum, (Sorghum, bicolor, L Moench) is the 5 th important food crop in the world. Sorghum is vitally important cereals for maintenance of food security in Africa. It’s belongs to the grass family graminea. Sorghum in Africa is processed into a very wide variety of attractive and nutritious traditional foods, such as semi-leavened bread, couscous, dumplings and fermented. Sorghum is an excellent source to assist digestion, and is rich in dietary fiber, prevents cancer and controls diabetes. In potential for sorghum to be the driver of economic development in Africa is enormous. Continuing focused fundamental and applied research is essential to unleash sorghum’s capacity to be the cornerstone of food security in Africa. Full Text: PDF DOI: 10.15640/jaes.v6n2a16

Morphology and fitness components of wild × crop F1hybrids ofSorghum bicolor(L.) in Ethiopia: implications for survival and introgression of crop genes in the wild pool

Natural hybridization between wild/weedy and crop species often results in rare hybrids, which can be more weedy and difficult to control. Moreover, the advent of transgenic crop plants raises questions of biosafety risk assessment on the consequences of rare hybrids with possible fitness enhancing genes on the environment. This study aimed at measuring the fitness components of wild–crop sorghum hybrids for various juvenile survival and adult morphological and fertility characters as part of the risk assessment of transgenic sorghum in Africa where the crop was believed to have first domesticated and serves as the major staple. Out of a pool of hybrids made in 2010 from 23 wild sorghum accessions and two released cultivated sorghum varieties using hand emasculation techniques, seven were selected for the field study of their fitness components in 2011. The study confirmed that crop–wild hybrids of sorghum are fertile. Two approaches were followed (relative fitness and mid-parent heterosis) which showed that most of the hybrids were as fit as their wild parents, and in some cases they showed mid-parent heterosis for the measured traits. The results of this study highlighted a potential risk that hybrids carrying crop genes (including herbicide resistance transgenes) could pose because they could be more weedy than their wild/weedy parents if transgenic sorghum is deployed in regions where the wild and cultivated sorghum populations coexist, such as in Ethiopia and in other parts of Africa.

Biofortified sorghum in Africa: using problem formulation to inform risk assessment

Biofortified sorghum in Africa: using problem formulation to inform risk assessment

Host plant diversity of Sesamia calamistis: cytochrome b gene sequences reveal local genetic differentiation

Abstract Sesamia calamistis Hampson (Lepidoptera: Noctuidae) is one of the indigenous stem borer pests associated with maize (Zea mays L.) and sorghum [Sorghum bicolor (L.) Moench] (both Poaceae) in Africa. Its pest status varies across the continent and this has been attributed to variation in diet breadth and ecological preferences among populations. Its larvae were found on 12 plant species during a study initiated at four sites (Muhaka, Mtito Andei, Kakamega, and Suam) in Kenya to estimate its diet breadth and genetic population structure. Ten of the infested plant species belonged to the family Poaceae [Echinochloa haploclada (Stapf) Stapf, Eleusine corocana L., Eleusine jaegeri Pilg., Panicum deustum Thunb, Panicum maximum Jacquin, Pennisetum purpureum Schumacher, Setaria verticillata (L.) P. Beauv., Sorghum arundinaceum (Desvaux) Stapf, S. bicolor, and Z. mays]; the other two were Cyperaceae: Cyperus distans L. and Cyperus dives Delile. Combined with collections from other African countries (Uganda, South Africa, Benin, Ghana, Nigeria, and Togo), comparisons of partial cytochrome b sequences revealed the presence of 68 haplotypes that differentiated into clades I and II. In Kenya, the two clades colonized different regions, except in Mtito Andei where they co‐existed. Individuals from Mtito Andei could be separated based on their host plants: clade I with 14 haplotypes was found mainly on maize (78.6%), whereas clade II with 10 haplotypes was found mainly among wild host plants (63.6%). Detection of divergence among these clades with cytochrome b suggests that their evolutionary separation may have taken place about one million years ago. This article discusses the potential implication of this differentiation for the management of S. calamistis as a pest of maize and sorghum in Africa.

Relationships Between Sources and Levels of Nitrogen Fertilization and the Control of Striga hermonthica in Sorghum

Striga hermonthica has been identified as an economic parasitic weed affecting high grain yield production of sorghum in Africa particularly Nigeria. Seven sorghum varieties were evaluated for three years (1998-2000) in soil treated with Striga seeds using two sources of nitrogen fertilizer and at five levels of nitrogen to study their association in the control of Striga. The experiment was split-split plot with three replication having sorghum varieties as main plot, source of fertilizer as sub-plot and levels of N as sub-sub plot treatments. There were no significant differences among sources of fertilizer and their interactions. Levels of N and varieties were significant for all the traits (p<0.001). There was positive and significant association between levels of N applied and plant vigour, dry matter yield (shoot and root) p<0.01 and Striga count (p<0.05). The significant linear relationship obtained, recognized plant vigour, dry matter yield and Striga count as beneficial Striga resistance indicator. Between 50 to 100 ppm (when converted 110 to 170 kg of N ha-1) is significant in the control of Striga. SK-5912, KSV-4, KSV-8 and NR71150 are potential sources of Striga resistance.

Genetic Characterization of Cercospora sorghi from Cultivated and Wild Sorghum and Its Relationship to Other Cercospora Fungi

ABSTRACT Genetic variability and population structure of Cercospora sorghi from wild and cultivated sorghum were investigated to gain insight into their potential impact on epidemics of gray leaf spot of sorghum in Africa. Population structure was examined using data derived from amplified fragment length polymorphism (AFLP) of C. sorghi by Nei's test for population differentiation, G(ST), and analysis of molecular variation (AMOVA). Two ecological populations of C. sorghi in Uganda were devoid of population structure (G(ST) = 0.03, small ef, CyrillicF(ST) = 0.01, P = 0.291). AMOVA revealed that genetic variability was due mainly to variations within (99%) rather than between (0.35%) populations, and Nei's genetic distance between the two populations was 0.014. Phenetic analysis based on AFLP data and polymerase chain reaction-restriction fragment length polymorphism analyses of the internal transcribed spacer regions of rDNA and mitochondrial small subunit rDNA separated Cercospora cereal pathogens from dicot pathogens but did not differentiate among C. sorghi isolates from wild and cultivated sorghum. Our results indicate that Ugandan populations of C. sorghi compose one epidemiological unit and suggest that wild sorghum, while not affecting genetic variability of the pathogen population, provides an alternative host for generating additional inoculum.

Effects of Calyx Fluid from a Population of Cotesia sesamiae (Cameron) (Hymenoptera: Braconidae) on the Immune Response of its Host Busseola fusca Fuller (Lepidoptera: Noctuidae)

Busseola fusca Fuller is one of the major lepidopteran stemborers of maize and sorghum in Africa. Cotesia sesamiae (Cameron) (Hymenoptera: Braconidae) is an indigenous, gregarious larval endoparasitoid that attacks mid- to late-instar stemborer larvae, which is reported to be one of the most important larval parasitoids of B. fusca in many countries in sub-Saharan Africa. Previous work has shown that two biotypes of C. sesamiae occur in Kenya which express differential abilities to develop in B. fusca. A biotype from western Kenya successfully develops in B. fusca, while a biotype from the eastern coastal area does not. We treated fourth-instars of B. fusca with calyx fluid from C. sesamiae from western Kenya (Kitale) before offering them to C. sesamiae from the Coast (Mombasa) for oviposition, and found that the eggs were not encapsulated. This suggests that factors in the calyx fluid of C. sesamiae from the western Kenya biotype were responsible for suppressing the immune system of B. fusca. We speculate that polydnaviruses in the calyx fluid were involved in disarming the host immune system, and that the polydnaviruses in the two biotypes are genetically different.

Fusarium andiyazi sp. nov., a New Species from Sorghum

We describe a new Fusarium species in sec- tion Liseola from sorghum in Africa and the United States. This species is distinguished morphologically by the production of unique pseudochlamydospores in carnation leaf pieces on carnation leaf agar, and appears to be most closely related to F thapsinum. The new species also can be distinguished molecu- larly by means of Amplified Fragment Length Poly- morphisms, AFLPs. Strains with both MAT-1 and MAT-2 mating types were identified, but no sexual stage was generated in crosses made under labora- tory conditions.

Fusarium andiyazi sp. nov., a new species from sorghum

We describe a new Fusarium species in section Liseola from sorghum in Africa and the United States. This species is distinguished morphologically by the production of unique pseudochlamydospores in carnation leaf pieces on carnation leaf agar, and appears to be most closely related to F. thapsinum. The new species also can be distinguished molecularly by means of Amplified Fragment Length Polymorphisms, AFLPs. Strains with both MAT-1 and MAT-2 mating types were identified, but no sexual stage was generated in crosses made under laboratory conditions.

Developments in sorghum food technologies

This chapter describes the major advances that have taken place in the development of sorghum food processing technologies, and examine the challenges that still have to be met. Tremendous strides have been made in developing sorghum food processing technologies. Two examples where the technologies have been successfully implemented are: the industrialization of sorghum brewing, taking it from a rural craft to a 20,000 liter batch scale, and brewing conventional beer with sorghum grain and enzymes. However, the implementation of other technologies, for example, composite breads, is notably lacking. One major factor limiting utilization of sorghum in Africa appears to be the unavailability of cost-efficient, reliable supplies of sorghum grain of acceptable quality for making high quality flour. The challenge, therefore, appears to revolve around a holistic approach to implementation, involving: economic studies, government programs, seed supply, grain production, selection of appropriate technologies, and training of operators, consumer awareness, and grain and product quality standards.

Exploiting chemical ecology and species diversity: stem borer and striga control for maize and sorghum in Africa

Stem borers, comprising the larvae of a group of lepidopterous insects, and parasitic witchweeds, particularly Striga hermonthica and S asiatica, cause major yield losses in subsistence cereal production throughout sub-Saharan Africa. Studies are described that have led to the development of a ‘push-pull’ strategy for minimising stem borer damage to maize and sorghum. This involved the selection of plant species that could be employed as trap crops to attract colonisation away from the cereal plants, or as intercrops to repel the pests. The two most successful trap crop plants were Napier grass, Pennisetum purpureum, and Sudan grass, Sorghum sudanensis. The intercrop giving maximum repellent effect was molasses grass, Melinis minutiflora, but two legume species, silverleaf, Desmodium uncinatum, and greenleaf, D intortum, gave good results and had the added advantage of suppressing development of S hermonthica. In terms of stem borer control, the plant chemistry responsible involves release of attractant semiochemicals from the trap plants and repellent semiochemicals from the intercrops. With M minutiflora, parasitism of stem borers was also increased by certain chemicals repellent to ovipositing adults. The mechanism of striga control has not been fully elucidated, but allelopathic effects from the Desmodium species have been shown to involve stimulation of germination and interference with haustorial development. Significant beneficial effects have been obtained with the individual components of these push-pull strategies. However, the most robust crop-protection package is obtained when these components are combined. The trap crop and intercrop plants also provide valuable forage for cattle, often reared in association with subsistence cereal production. There has been considerable take-up of the system within the communities where farmer-managed trials have been carried out, particularly in the Trans Nzoia and Suba districts of Kenya, and the programme is set to expand throughout and beyond Kenya. © 2000 Society of Chemical Industry

Interactions of host plant resistance and biological control of stemborers in sorghum

Lepidopteran stemborers are major limiting factors in the production of maize and sorghum in Africa and Asia. Host-plant resistance and biological control are important components of an IPM programme and can effectively maintain pest populations below economic threshold levels, especially in low-input subsistence farming systems. When damaged by herbivores, plants produce allelochemicals which can attract natural enemies of the pest. These volatiles occur systematically throughout the plant and are different from those emitted in response to mechanical damage. We report evidence of plant volatiles-mediated differential reaction of parasitoid activity to sorghum genotypes. These volatiles could have a positive impact on the efficacy of stemborer parasitoids, leading to increased host finding or increased searching efficiency, thereby enhancing the suppression of stemborer populations. In a single-season case study, parasitoid activity was higher in stemborer-resistant genotypes than in susceptible ones and varied with crop age. Knowledge of such interactions should be explored and intensified by plant breeders and chemical ecologiste aiming at producing plant materials possessing appreciable levels of resistance to stemborers and able to encourage natural enemy activity in cereal-based ecosystems.

La relation entre le Striga hermonthica et ses hôtes: une synthèse

The parasitic weed Striga hermonthica causes considerable yield losses in maize, pearl millet, and sorghum in Africa. The extent of the damage caused to crops is related to their close interaction with the parasite. The S. hermonthica seed germinates in response to germination stimulants exuded by cereal roots. The rootlet extremity then turns into a haustorium that attaches itself to the host root and penetrates its tissue. In this manner, a connection is established between the vascular systems of both plants, allowing absorption of water, minerals, and organic compounds that are essential for the parasite's development. S. hermonthica also affects the host's metabolism and photosynthesis. No effective control method against the parasite is available for the African peasants. The utilization of germination stimulants and herbicides, the rotation practice, and intercropping as well as biological control and varietal selection have given disappointing results so far. A better understanding of host resistance mechanisms is necessary to develop new methods for the control of the parasite. Keywords: Striga hermonthica, germination, haustorium, host–parasite interaction, control methods, resistance.

Insect pests of sorghum in Africa

Several insect pests are associated with the sorghum crop, but essentially a few are considered key pests. These include shootfly, several species of stem borers, sorghum midge and a complex of head bugs. Other insect pests which are occasionally devastating and sporadic include leaf feeders and defoliators (Lepidoptera of various genera, locusts, grasshoppers, aphids, beetles, etc.) and also several species of head worms and head beetles. A list of 101 insect pests of sorghum occurring in Africa is presented.