139 research outputs found
Analysis of the Economic Impact of Sorghum and Millet Research in Mali
Sorghum (Sorghum bicolor (L.) Moench) and pearl millet [Pennisetum glaucum] are very impor tant to the
economy and people of Mali. But, their productivity is low given the reliance on traditional, low-input
production practices. The Institut d'Economie Rurale (IER) was started soon after the country's independence
to find ways of improving the productivity of food crops in collaboration with regional and international
agricultural research institutes (e.g., IRAT, ICRISAT, CIRAD-CA) . A numbe r of improved seed-based
sorghum and millet technologies have since been developed and diffused. They were developed from two
approaches: (1) selection within local germplasm, which consisted of collecting, testing, purifying, and supplying
farmers with readily available materials. These are identified as Generation 1 materials; and (2) plant breeding,
which consisted of crossing with exotic germplasm, and pedigree selection. Outputs of this second approach are
identified as Generation 2 materials. This study evaluates the returns to sorghum and pearl millet research
investments in Mali by combining farm-level survey information from 1990 to 1995 with that from research and
extension in an economic surplus framework. The results indicate that by 1995, 30% of the sorghum and 3 7%
of the millet areas were sown to improved varieties. Th e estimated benefits from research and extension efforts
range from US 25 million (for pearl millet). These represent internal rates of
returns of 69% and 50%, respectively. A disaggregated analysis indicates higher yield gains and higher returns
to Generation 2 materials than to Generation 1 materials for bot h sorghum and pearl millet. Unit costs were also
much lower for Generation 2 materials. The major constraints cited by farmers as limiting their ability to adopt
improved materials include lack of information, lack of improved seeds, and low soil fertility. The study concludes
that the breeding philosophy should be diversified to respond to the need of the changing socioeconomic
environment with the recent devaluation of the CFA. It also recommends that efforts be made to improve the
economic farming environment to enable farmers to adopt mor e productive agricultural technologies which are
necessary for rural poverty alleviation and improvement in national food security
Participatory varietal selection with improved pearl millet in West Africa
A reconnaissance survey and participatory varietal selection trials (PVS) were conducted in four major pearl millet-growing countries of the Sahel between 2001 and 2003. The studies aimed to identify farmers' preferences in improved pearl millet varieties, increase awareness, test new varieties and enhance farmers' access to the improved varieties. Farmers selected five out of 10 tested varieties, with preferred characteristics, namely, maturity cycles of 80-90 d in the Sahel and 90-100 d in the Sudanian agro-ecozones, acceptable grain yield, compact and long (30-100 cm) panicles, a large number of tillers with panicles, adaptation and an acceptable taste. Farmers indicated that their local varieties were of superior adaptation and taste. They mentioned that hindrances to uptake and sustained use of improved varieties were due to lack of awareness, traditional values, seed unavailability, early maturity, bird damage and lack of fertilizer. The strong genotype × environment interactions in the Sahel suggests that breeding should be directed towards producing varieties adapted to specific zones rather than for wide adaptation. Notably, since farmers often cultivate pearl millet without any soil amendments, it may be advisable to disseminate varieties as a package (with fertilizer and agronomic instructions) rather than as varieties alone in a PVS programme, in order to achieve the full potential of improved varieties. The PVS trials are synergistic to plant breeding in identifying varieties suitable for harsh environments, which are difficult to duplicate in the research station. However, in the absence of formal distribution seed systems in the trial countries, village- or community-based seed production of varieties selected by farmers appears critical to the sustainable adoption of selected varieties
Understanding farm trajectories and development pathways: Two decades of change in southern Mali
Institutional support for smallholders has been the motor for the expanding cotton production sector in southern
Mali since the 1970s. Smallholder farms exhibit diverse resource endowments and little is known on how they
benefit from and cope with changes in this institutional support. In this paper we explore farm trajectories during
two decades (1994 to 2010) and their link with farm resource endowment and government support. We distinguished
a favourable period for cotton production and an unfavourable period during which institutional support
collapsed. A panel survey that monitored 30 farms in the Koutiala district in southern Mali over this period was
analysed. Based on indicators of resource endowment and using Ascending Hierarchical Classification (AHC),
farms were grouped into four types: High Resource Endowed farms with Large Herds (HRE-LH), High
Resource Endowed (HRE) farms, Medium Resource Endowed (MRE) farms and Low Resource Endowed (LRE)
farms. Average yield, labour productivity and food self-sufficiency status of each type were calculated. Farms remaining
in the same type were classified as ‘hanging in’, while farms moving to a type of higher yields, labour
productivity and food self-sufficiency status were classified as ‘stepping up’, and farms following the opposite trajectory
of deteriorating farming conditions were classified as ‘falling down’. The LRE farms differed from all other
farm types due to lower yields, while both LRE and HRE farms differed from the MRE and HRE-LH farm types due
to a combination of less labour productivity and less food self-sufficiency. During those two decades, 17% of the
farms ‘stepped up’, while 70% of the farms remained ‘hanging in’, and only 13% of the farms ‘fell down'. We found
no obvious negative impact of the collapse of government support on farm trajectories. For MRE, HRE and HRELH
farms, average N and P use intensity increased from 1994 to 2004 and then decreased during the following
cotton crisis. On the other hand, organic fertilizer use intensity increased continuously over the entire monitoring
period for HRE-LH and MRE farms. Crop yields did not change significantly over time for any farm type and labour
productivity decreased. We discuss how technical options specific for different farm types (increase in farm
equipment, sale of cereals, incorporation of legumes and intensification of milk production) and broader institutional change (improvement in finance system and infrastructure, tariffs) can enhance ‘step up’ trajectories for farming households and avoid stagnation (‘hanging in’) of the whole agricultural sector
Performance of dual-purpose pearl millet genotypes in West Africa: Importance of morphology and phenology
Pearl millet ( Pennisetum glaucum (L.) R. Br.) is a cereal crop vital
for food security in West and Central Africa. Its byproducts also serve
as fodder for livestock, especially during dry seasons. The objective
of this study was to evaluate selected genotypes from West African
pearl millet breeding programmes, for dual-purpose (grain and fodder)
and elucidate prospects for future breeding. A total of 83
open-pollinated varieties (OPVs), five composites, six landraces, one
synthetic and five hybrids were evaluated at 14 environments in Burkina
Faso, Mali, Niger and Senegal during the rainy seasons of 2015 and
2016. Combined analysis of data revealed significant differences among
genotypes and prevalence of high genotype-by-environment interaction
effects. Two stability analyses models consistently indicated that
genotypes 10 (SMILBF10), 14 (SMILBF14) and 39 (SMILML5) were widely
adaptable across the region. Plant height, panicle length and panicle
yield showed significant positive correlations with grain yield; while
days to flowering was negatively correlated. Positive correlation
between grain and fodder yields indicate possibility for simultaneous
improvement involving the two important traits. This result suggests
that germplasm exchange and regionally integrated breeding programmes
are important for the identification of widely adapted dual-purpose
varieties of pearl millet, particularly in West African drylands.Le mil\ua0\ue0\ua0chandelle ( Pennisetum glaucum (L.) R. Br.)
Est une c\ue9r\ue9ale vitale pour la s\ue9curit\ue9 alimentaire
en Afrique de l\u2019Ouest et centrale. Ses sous-produits servent
\ue9galement de fourrage pour le b\ue9tail, en particulier pendant
les saisons s\ue8ches. L\u2019objectif de cette \ue9tude
\ue9tait d\u2019\ue9valuer des g\ue9notypes
s\ue9lectionn\ue9s \ue0 partir des programmes de s\ue9lection
du mil\ua0\ue0\ua0chandelle d\u2019Afrique de l\u2019Ouest,
pour l\u2018 usage double (c\ue9r\ue9ales et fourrage) et
d\u2019\ue9lucider les perspectives de s\ue9lection dans le
future. Les 83 vari\ue9t\ue9s \ue0 pollinisation libre (OPV),
cinq composites, six vari\ue9t\ue9s locales, une synth\ue9tique
et cinq hybrides ont \ue9t\ue9 \ue9valu\ue9s dans les 14
environnements au Burkina Faso, au Mali, au Niger et au
S\ue9n\ue9gal pendant les saisons des pluies de 2015 et 2016.
L\u2018 analyse combin\ue9e des donn\ue9es ont
r\ue9v\ue9l\ue9 des diff\ue9rences significatives entre les
g\ue9notypes et la pr\ue9valence des effets \ue9lev\ue9s
d\u2019interaction g\ue9notype-par-environnement. Deux mod\ue8les
d\u2019analyses de stabilit\ue9 ont syst\ue9matiquement
indiqu\ue9 que les g\ue9notypes 10 (SMILBF10), 14 (SMILBF14) et 39
(SMILML5) \ue9taient largement adaptables dans toute la r\ue9gion.
La hauteur de la plante, la longueur de la panicule et le rendement de
la panicule ont montr\ue9 des corr\ue9lations positives
significatives avec le rendement en grains; tandis que les jours avant
la floraison \ue9taient corr\ue9l\ue9s n\ue9gativement. Une
corr\ue9lation positive entre les rendements en c\ue9r\ue9ales et
en fourrage indique la possibilit\ue9 d\u2019une am\ue9lioration
simultan\ue9e impliquant les deux caract\ue8res importants. Ce
r\ue9sultat sugg\ue8re que l\u2019\ue9change de mat\ue9riel
g\ue9n\ue9tique et les programmes de s\ue9lection
int\ue9gr\ue9s au niveau r\ue9gional sont importants pour
l\u2019identification de vari\ue9t\ue9s \ue0 l\u2018 usage
double largement adapt\ue9es de mil \ue0 chandelle, en particulier
dans les zones arides d\u2019Afrique de l\u2019Ouest
Population structure and diversity in Valencia peanut germplasm collection
Valencia peanuts [Arachis hypogaea L. subsp.
fastigiata Waldron var. fastigiata (Waldron)
Krapov. & W. C. Greg.] are well known for their
in-shell market value. Assessment of genetic
diversity is key to the success of developing
improved cultivars with desirable agronomic
and quality traits. Seventy-eight U.S. Valencia
core collection accessions together with 36
Valencia accessions representing the global
peanut mini-core collection were used to study
population structure and diversity and to identify
genetically diverse Valencia germplasm for use
in peanut breeding. Fifty-two simple sequence
repeats loci amplifi ed 683 alleles, with an average
of 13 alleles per locus. The mean polymorphism
information content and gene diversity,
respectively, were 0.270 and 0.335. The pairwise
genetic distance ranged from 0.143 to
0.474, with an average of 0.631. Neighbor-joining
clustering, principal coordinate analysis, and
STRUCTURE analysis consistently separated
the Valencia germplasm into fi ve clusters with
two distinct major groups. The fi rst major group
consisted of genotypes from South America
(64%) with few accessions from Africa, North
America, Caribbean, and European regions. The
second group consisted of accessions mostly
from diverse regions of Africa, North and South
America, Asia, and the Caribbean. However, the
structuring was not related to the geographic
origin and several admixtures were observed.
The information generated in this study and
phenotyping of this material for biotic and abiotic
stress responses and yield-quality traits will
facilitate selection of trait-specifi c, genetically
diverse parents for developing Valencia peanut
cultivars with a broad genetic base
Phosphorus uptake and utilization efficiency in West African pearl millet inbred lines
Pearl millet [Pennisetum glaucum (L.) R. Br] production on the acid sandy Sahelian soils in West Africa (WA) is severely limited by low plant-available phosphorus (P) in addition to erratic rainfall. We sought to examine the genetic variability for P uptake and P utilization efficiency in 180 WA pearl millet inbred lines or subsets thereof under low (LP) and high P (HP) conditions in one field and two pot experiments, determine the relationships among the measured traits and grain yield under field conditions at three other independent WA sites, and identify potential secondary selection traits for improving grain yield under LP. We observed genetic variation for P uptake and utilization in both seedling and mature plants. P utilization efficiency increased under LP conditions. Total P uptake was more important for grain production than P utilization under LP field conditions (r = 0.57*** vs r = 0.30***). The estimated response to indirect selection was positive for most of the measured morphological and P-efficiency parameters. We conclude that both seedling and mature plant traits are potentially useful as secondary traits in selection of pearl millet for low-P adaptation. These results should be validated using heterozygous pearl millet genetic materials. Ultimately, pearl millet breeding activities for low P tolerance in WA should be integrated with other system-oriented research such as nutrient cycling, intercropping or rotations with legumes, better crop-tree-livestock integration, and modest applications of locally available rock phosphate
Combining ability patterns among West African pearl millet landraces and prospects for pearl millet hybrid breeding
Pearl millet (Pennisetum glaucum (L.) R. Br.) is an important hybrid crop in India. However, to date limited pearl millet hybrid development has been undertaken in West Africa (WA), which is the center of pearl millet origin and diversity and where this crop is most important outside India. Using a diverse set of WA pearl millet germplasm, objectives of this study were to determine the superiority of population hybrids over open-pollinated varieties for agro-morphological and agronomic traits in WA pearl millet germplasm; and (ii) to derive strategies for pearl millet hybrid breeding in WA, based on quantitative-genetic parameters, combining ability and heterotic patterns among geographically close versus distant pearl millet populations. A 10 × 10 factorial mating design was performed with four parental OPVs from each of five WA countries. The 100 population hybrids and their parents were tested for 14 traits at six locations in one year, thereby using contrasting locations to indirectly sample the rainfall variability inherent to WA pearl millet production environments. Grain yield showed an average panmictic midparent heterosis (PMpH) of 16.7%, ranging from −26 to 73%. The mean grain yield of hybrids based on inter-country crosses did not differ significantly from intra-country crosses. Geographic distance between parents was positively correlated with hybrid grain yield (r = 0.31), but not with PMpH . Some crosses between accessions from Niger/Nigeria and Senegal were outstanding. Predictability of population hybrid performance for grain yield was moderate based on midparent values (r = 0.43) and slightly better based on general combining ability (GCA) (r = 0.56). Overall, pearl millet hybrid breeding in WA seems very promising, but there do not seem to be clear “natural” heterotic groups among WA pearl millet landraces. Such heterotic groups as the basis of sustainable hybrid breeding need rather to be created systematically, by building on existing combining ability patterns and aiming to maximize combining ability between the groups
Agro-morphological Characterization of West and Central African Pearl Millet Accessions
Pearl millet [Pennisetum glaucum (L.) R. Br.] was
domesticated in Sahelian West Africa. This highly
outcrossing crop is one of the most important
staple cereals in the semiarid tropics, adapted to
very harsh rain-fed conditions. Agro-morphological
characterization of local germplasm is very
important to better understand existing diversity,
ease targeted genetic broadening of breeding
populations, and potentially link this knowledge
to genotypic information. The objectives of our
study were to (i) characterize West and Central
African (WCA) pearl millet accessions based on
their agro-morphological traits; (ii) evaluate the
possibility to group accessions based on their
agro-morphological characteristics; (iii) determine
geographic patterns of phenotypic differentiation;
and (iv) derive conclusions for pearl millet
improvement in WCA. A total of 360 early-tomedium
maturity accessions were phenotyped
for 12 agro-morphological traits at six environments
in WCA. Wide ranges of all observed traits
indicated a high diversity of the tested accessions.
Principal component analysis revealed
very large diversity within individual countries,
especially within Mali and Burkina Faso. Some
limited grouping of accessions from Niger, Senegal,
Cameroon, Morocco, and Mauritania was
observed for individual principal component
axes. Geographical differentiation and country
differences were detected for several traits. The
results and data presented in our study reflect
WCA pearl millets’ tremendous diversity and
adaptability to a wide range of environments and
give a sound basis for breeders to select and utilize
this germplasm to serve the manifold needs
of WCA pearl millet farmers
Microbiota that affect risk for shigellosis in children in low-income countries
Pathogens in the gastrointestinal tract exist within a vast population of microbes. We examined associations between pathogens and composition of gut microbiota as they relate to Shigella spp./enteroinvasive Escherichia coli infection. We analyzed 3,035 stool specimens (1,735 nondiarrheal and 1,300 moderate-to-severe diarrheal) from the Global Enteric Multicenter Study for 9 enteropathogens. Diarrheal specimens had a higher number of enteropathogens (diarrheal mean 1.4, nondiarrheal mean 0.95; p<0.0001). Rotavirus showed a negative association with Shigella spp. in cases of diarrhea (odds ratio 0.31, 95% CI 0.17–0.55) and had a large combined effect on moderate-to-severe diarrhea (odds ratio 29, 95% CI 3.8–220). In 4 Lactobacillus taxa identified by 16S rRNA gene sequencing, the association between pathogen and disease was decreased, which is consistent with the possibility that Lactobacillus spp. are protective against Shigella spp.–induced diarrhea. Bacterial diversity of gut microbiota was associated with diarrhea status, not high levels of the Shigella spp. ipaH gene.publishedVersio
Diarrhoeal disease and subsequent risk of death in infants and children residing in low-income and middle-income countries: analysis of the GEMS case-control study and 12-month GEMS-1A follow-on study
Background: The Global Enteric Multicenter Study (GEMS) was a 3-year case-control study that measured the burden,
aetiology, and consequences of moderate-to-severe diarrhoea (MSD) in children aged 0–59 months. GEMS-1A,
a 12-month follow-on study, comprised two parallel case-control studies, one assessing MSD and the other less-severe
diarrhoea (LSD). In this report, we analyse the risk of death with each diarrhoea type and the specific pathogens
associated with fatal outcomes.
Methods: GEMS was a prospective, age-stratified, matched case-control study done at seven sites in Africa and
Asia. Children aged 0–59 months with MSD seeking care at sentinel health centres were recruited along with one
to three randomly selected matched community control children without diarrhoea. In the 12-month GEMS-1A
follow-on study, children with LSD and matched controls, in addition to children with MSD and matched controls,
were recruited at six of the seven sites; only cases of MSD and controls were enrolled at the seventh site. We
compared risk of death during the period between enrolment and one follow-up household visit done about
60 days later (range 50–90 days) in children with MSD and LSD and in their respective controls. Approximately
50 pathogens were detected using, as appropriate, classic bacteriology, immunoassays, gel-based PCR and
reverse transcriptase PCR, and quantitative real-time PCR (qPCR). Specimens from a subset of GEMS cases
and controls were also tested by a TaqMan Array Card that compartmentalised probe-based qPCR for
32 enteropathogens.
Findings: 223 (2·0%) of 11 108 children with MSD and 43 (0·3%) of 16369 matched controls died between study
enrolment and the follow-up visit at about 60 days (hazard ratio [HR] 8·16, 95% CI 5·69–11·68, p<0·0001). 12 (0·4%)
of 2962 children with LSD and seven (0·2%) of 4074 matched controls died during the follow-up period (HR 2·78,
95% CI 0·95–8·11, p=0·061). Risk of death was lower in children with dysenteric MSD than in children with nondysenteric MSD (HR 0·20, 95% CI 0·05–0·87, p=0·032), and lower in children with LSD than in those with nondysenteric MSD (HR 0·29, 0·14–0·59, p=0·0006). In children younger than 24 months with MSD, infection with
typical enteropathogenic Escherichia coli, enterotoxigenic E coli encoding heat-stable toxin, enteroaggregative E coli,
Shigella spp (non-dysentery cases), Aeromonas spp, Cryptosporidium spp, and Entamoeba histolytica increased risk of
death. Of 61 deaths in children aged 12–59 months with non-dysenteric MSD, 31 occurred among 942 children qPCRpositive for Shigella spp and 30 deaths occurred in 1384 qPCR-negative children (HR 2·2, 95% CI 1·2–3·9, p=0·0090),
showing that Shigella was strongly associated with increased risk of death.
Interpretation: Risk of death is increased following MSD and, to a lesser extent, LSD. Considering there are
approximately three times more cases of LSD than MSD in the population, more deaths are expected among children
with LSD than in those with MSD. Because the major attributable LSD-associated and MSD-associated pathogens are
the same, implementing vaccines and rapid diagnosis and treatment interventions against these major pathogens are
rational investments
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