Effects of Different Seeds Pretreatments on the Germination of Five Local Trees: Four From The Fabaceae Family and One From the Bombacacea

The problem of the effectiveness of the established pre-treatments of seeds of local tree species is posed more and more often, with acuity. It appears necessary that studies are led to explore new methods of pre-treatment, or to update the old instructions applied, for a better success and at lower cost, of the production of seedlings. The present study concerned five species: Acacia nilotica, Adansonia digitata, Parkia biglobosa, Piliostigma reticulatum and Tamarindus indica. The methodology involved subjecting the seeds to three different pretreatments: (i) seeds treated with sulfuric acid (T0), (ii) seeds soaked in hot water for 24 hours (T1), (iii) seeds soaked in hot water for 48 hours (T2). For Acacia nilotica seeds, the different pretreatments did not result in statistically different germination rates. The germination rates are 77%, 65% and 62% (respectively for soaking in hot water for 48 hours, sulfuric acid and soaking in hot water for 24 hours). The different pretreatments also do not result in different germination rates for Tamarindus indica. Indeed, the germination rates after 30 days for this species are good but statistically identical (85% for the pretreatment with sulfuric acid and hot water for 24 hours). For Adansonia digitata, Parkia biglobosa and Piliostigma reticulatum, the sulfuric acid pretreatment gave the best germination rate (49%, 54% and 41% respectively). The results of this study may have practical consequences in terms of management of the different species studied. They show that immersing in boiling water and left for 24 hours and 48 hours yields fairly satisfactory germination rates for Acacia nilotica and Tamarindus indica seeds. These inexpensive techniques, accessible to all, can be considered as means to easily produce seedlings of these species

Allometric equations for below-ground biomass of four key woody species in West African savanna-woodlands

Accurate estimates of both above-ground biomass (AGB) and below-ground biomass (BGB) are essential for estimating carbon (C) balances at various geographical scales and formulating effective climate change mitigation programs. However, estimating BGB is challenging, particularly for forest ecosystems, so robust allometric equations are needed. To obtain such equations for savanna-woodlands of the West African north sudanian zone, we selected four common native woody species (Anogeissus leiocarpa (DC.) Guill. & Perr., Detarium microcarpum Guill. & Perr., Piliostigma thonningii (Schumach.) Milne-Redh. and Vitellaria paradoxa C. F. Gaertn.). At two sites in Burkina Faso, we determined the BGB of 30 trees of each of these species by excavation, and measured various above-ground dimensional variables. The root: shoot ratio varied widely among the species, from 0.1 to 3.4. Depending on the species, allometric equations based on stem basal area at 20 cm height, basal area at breast height and tree height explained 50-95% of the variation in BGB. The best generic equation we obtained, based on basal area at 20 cm, explained 60% of the variation in BGB across the species. Three previously published generic allometric equations underestimated BGB by 8 to 63%. The presented equations should significantly improve the accuracy of BGB estimates in savanna-woodlands and help avoid costly needs to excavate root systems.Peer reviewe

Socioeconomic determinant of microdose adoption and impact on food security and household incomes

Adoption of micro-dosing can help poor rural men and women farmers to increase crop yields by 44-120% and net profit by 50 to 130%. The presentation shows results of on-farm trials for fertilizer micro-dosing and rainwater harvesting. It compares inputs of labour under different methodologies relative to agricultural outcomes. Women allocate percentage-wise more land for micro dosing technique than men. The micro-dosing technique adoption reduces the length of food shortages for one month among men and three months among women. Increasing the productivity of rainfed crops is a necessity

Genome-wide analysis of ivermectin response by Onchocerca volvulus reveals that genetic drift and soft selective sweeps contribute to loss of drug sensitivity

Treatment of onchocerciasis using mass ivermectin administration has reduced morbidity and transmission throughout Africa and Central/South America. Mass drug administration is likely to exert selection pressure on parasites, and phenotypic and genetic changes in several Onchocerca volvulus populations from Cameroon and Ghana-exposed to more than a decade of regular ivermectin treatment-have raised concern that sub-optimal responses to ivermectin's anti-fecundity effect are becoming more frequent and may spread.Pooled next generation sequencing (Pool-seq) was used to characterise genetic diversity within and between 108 adult female worms differing in ivermectin treatment history and response. Genome-wide analyses revealed genetic variation that significantly differentiated good responder (GR) and sub-optimal responder (SOR) parasites. These variants were not randomly distributed but clustered in ~31 quantitative trait loci (QTLs), with little overlap in putative QTL position and gene content between the two countries. Published candidate ivermectin SOR genes were largely absent in these regions; QTLs differentiating GR and SOR worms were enriched for genes in molecular pathways associated with neurotransmission, development, and stress responses. Finally, single worm genotyping demonstrated that geographic isolation and genetic change over time (in the presence of drug exposure) had a significantly greater role in shaping genetic diversity than the evolution of SOR.This study is one of the first genome-wide association analyses in a parasitic nematode, and provides insight into the genomics of ivermectin response and population structure of O. volvulus. We argue that ivermectin response is a polygenically-determined quantitative trait (QT) whereby identical or related molecular pathways but not necessarily individual genes are likely to determine the extent of ivermectin response in different parasite populations. Furthermore, we propose that genetic drift rather than genetic selection of SOR is the underlying driver of population differentiation, which has significant implications for the emergence and potential spread of SOR within and between these parasite populations

Influence of Land Tenure on Agroforestry Parkland Phyto-Diversity and Stand Structure in Sudanian Zone of Burkina Faso, West Africa

Savanna Zone of Burkina Faso is characterized by the increasing population growth due to human migration from the north and central regions of the country for cultivating agricultural land and pastures. This situation induced land-use changes, and social reorganization has led to new approaches to natural resources management. Tenure issues in natural resources management limit the adoption of agroforestry systems and effective land use scale. This paper describes the species composition, structure, and diversity of woody species on agroforestry parklands at Tiogo under two types of land tenures. Ecological and structural characteristics of vegetation patches were computed to characterize the species composition. A variety of diversity measures were calculated to determine the heterogeneity for each type of land tenure. A total of 49 woody species belonging to 19 families and 38 genera were identified, of which 44 and 48 species were recorded in non-landowners’ farms and landowners' farms, respectively. Leguminosae, Combretaceae and Anacardiaceae were the most abundant families. The dominant species in agroforestry parklands were Vitellaria paradoxa, Parkia biglobosa, Lannea microcarpa, Piliostigma reticulatum and Piliostigma thonningii. Analyses of variance of the entire woody vegetation of agroforestry parklands revealed no significant differences in terms of all computed indexes but showed that the landowners’ farms were the most diverse than non-landowners farms. The density of stems ≥5 cm dbh and the basal area were higher in landowner’s farms than in non-landowners farms. In both types of farms, the size class distributions of the vegetation produced a reverse J-shaped curve, supporting that agroforestry parkland in Tiogo is dominated by young individuals. The spatial distribution of the seedling was mainly clumped, reflecting the dominance of clonal propagation. Security of land and tree tenure is a necessary condition for any land-based investment (planting and protection of preferred species and soil amendment). The challenge to maintain parklands’ tree biodiversity in “good” condition also needs to consider the flexibility of land tenure and equitability sharing of the benefits from trees

Changes in Woody Vegetation over 31 Years in Farmed Parkland of the Central Plateau, Burkina Faso

Farmed parklands of the Central Plateau, Burkina Faso, integrate native woody vegetation with managed cropland. However, sapling survival in the parklands is increasingly threatened. This study characterized woody vegetation abundance along a 2.7 km long transect in the Doulou Basin, Boulkiemdé Province, Central West Region, to assess changes in vegetation composition since 1984. In addition, a householder survey was conducted to gain insight into tree uses and preferences and residents’ knowledge of regulations. In total, 4999 individuals from 26 tree species were recorded, including 123 individuals (11 species) with stem DBH ≥ 5 cm, and 4876 individuals (21 species) with stem DBH < 5 cm. The three species with the highest importance value index provided fruit for sale or self-consumption. Tree abundance was associated with soil type and topography; highest abundance was on Lixisol soils along the lower transect. Soil degradation and preference changes among residents since 1984 may have influenced tree abundance. Certain beneficial species (e.g., Vitellaria paradoxa) have declined in abundance, and certain exotics (Azadirachta indica and Eucalyptus camaldulensis) have expanded in distribution. Respondents expressed strongest interest in three species, including V. paradoxa, that show high versatility. These results supported the recorded tree composition. The respondents generally understood forest conservation regulations. Dissemination of regreening technology and awareness promotion among residents is essential for sustainable tree use in farmed parklands

No changes in soil organic carbon and nitrogen following long-term prescribed burning and livestock exclusion in the Sudan-savanna woodlands of Burkina Faso

Fire and overgrazing reduce aboveground biomass, leading to land degradation and potential impacts on soil organic carbon (SOC) and total nitrogen (TN) dynamics. However, empirical data are lacking on how prescribed burning and livestock exclusion impact SOC in the long-term. Here we analyse the effects of 19 years of prescribed annual burning and livestock exclusion on tree density, SOC and TN concentrations in the Sudanian savanna ecoregion at two sites (Tiogo and Laba) in Burkina Faso. Results revealed that neither livestock exclusion nor prescribed burning had significant impact on SOC and TN concentrations. The results at both sites indicate that 19 years of livestock and fire exclusion did not result in a significant increase in tree density compared to grazing and annual prescribed burning. The overall mean (± SEM) of SOC stocks in the 0–50 cm depth increment in the unburnt (53.5 ± 4.7 Mg C ha−1) and annually burnt (56.4 ± 4.3 Mg C ha−1) plots at Tiogo were not statistically different. Similarly, at Laba there was no significant difference between the corresponding figures in the unburnt (37.9 ± 2.6 Mg ha−1) and in the annually burnt plots (38.6 ± 1.9 Mg ha−1). Increases in belowground inputs from root turnover may have countered changes in aboveground biomass, resulting in no net change in SOC and TN. We conclude that, contrary to our expectation and current policy recommendations, restricting burning or grazing did not result in increase in SOC stocks in this dry savanna ecosystem

Impacts of water and soil conservation strategies on households’ food security in North West of Benin.

<p>*Bolded p-values are likelihood ratio test p-values and non-bolded p-values are Wald test p-values.</p>†<p>Likelihood ratio test p-values significant at the 5% level.</p