Phoeniciculture, or date palm cultivation plays a major socio-economic and ecological role. However, few studies have quantified the drivers of date palm cultivation and its socio-economic and environmental benefits in West African Sahel. Therefore, this study assessed the effect of anthropic and environmental factors on quantitative and qualitative production of dates palm in Niger. We conducted an ethnobotanical survey to collect data in the Sahelian and Saharian zones of Niger. We used permutation regression test to assess the influence of climatic conditions, fidelity of cultural practices implementation and the socio-economic level of producers on the date palm profitability. The Spearman rank correlation coefficients between the economic parameters and the geographical position of palm groves were also estimated based on the Spearman rank permutation test. A total of 60 producers were surveyed in ten villages of Sahelian and Saharian zones known as two main phoenicicultural areas in Niger. This analysis showed that date palm production varies quantitatively and qualitatively across agro-ecological zones. The study revealed also that ethnic groups influence the quantitative aspect of date palm production (P = 0.023), by socioeconomic parameters (P = 0.005) and by the index of fidelity to the cultural practice implementation (P = 0.035). The date palm production varies quantitatively (P = 0.001) and qualitatively (P = 0.033) according to the agro-climatic zones. The Spearman rank test shows a significant correlation between the quantitative and qualitative production, the geographical position of the palm groves and the depth of the water table. The profitability of the date palm seems not to be up to the phoenicicultural potential that can be the consequence of the poor implementation of the cultural practices, the socio-economic level of the producers and the environmental conditions.

The cultivation of date palm, a pillar of oasis agrosystem constitutes a real source of development in arid and semi-arid zones because of its fruit’s rich in sugars and various products, essential to daily life of the populations. In Chad, date production has experienced a decline since the sixties, in relation to diseases, pests and poorly performing cultivation techniques, environmental factors are major causes of the degradation of phoeniculture as well as insecurity and the phenomenon of rural exodus. In order to assess the potential of oasis agroecosystems based on the date palm in Chad, an ethnobotanical survey was carried out among date farmers of Sahara and Sahel. The cultivars of date palm is mainly cultivated in Sahara in the North of the country where it allows a rich and diversified subsistence agriculture (market gardening, fruit trees, cereals and fodder), which excludes the use of chemical inputs in production. Our study made it possible to highlight an important genetic diversity with more than 200 cultivars, resulting from empirical selection and multiplied by offshoot. In Sahara, date palms cultivars have only one fruit production season per year with satisfactory productivity, an acceptable price and farmers have a good knowledge of cultivation practises. In central part of the country corresponding to the Sahelian zone, oasis agrosystems are also found in basins. The climatic conditions favour two production seasons and the income from the sale of dates from the first fruit production season (April and May) is greater than those from the second production season (June to September). The strengthening of the local knowledge and the extension of palm groves made it possible to increase production and income and would contribute to food security and the maintenance of populations in Chad and more generally in Sahel’s countries.

The groundnut is a leguminous, olea-proteaginous, cultivated in all the tropical zones throughout the world. In Niger, groundnut is used both as a cash and food crop and is highly valued for its nutritional and economic qualities. In order to show the local diversity of groundnut and its place in the cultivation system in Niger, a prospecting survey and seed collection was conducted in the regions of Zinder, Maradi, Tahoua and Dosso, which account for more than 90% of the national production. Two hundred and seventeen (217) producers were surveyed, using a quota-oriented technic. It emerged from this study that groundnut is generally grown pure or in association with cereals (millet, sorghum) or other legumes (cowpea, sorrel, sesame). Few producers know the varieties they use (55 437, RRB, JL 24, FLEUR 11); the rest only know the local names of the varieties (El Laray, El Haoussa, MargaMarga, El Dakar, Mai Silbi, Garangagia, Bahaoussa, El Masar, Tsougouné, El Arba'in). This denomination depends on the origin of the variety, its morphology and earliness. The seeds are generally sold or used for transformation and the leaves are also either sold or kept for animals. Haulms are mostly given to animals during the dry season. The prices of haulms and seeds are higher during the same period and therefore vary according the periods. Producers cited several constraints related to groundnut production which are Insufficient fertilizer, diseases and insect pests, insufficient rainfall, and problem of seeds quality.

Several multivariate statistical methods are used in population genetics but there are very few studies that have revealed the strengths and weaknesses of different methods. Thus, this study aims to reveal the strengths and weaknesses of the different multivariate statistical methods used in population genetics through the world. This synthesis is carried out according to the methodology "Preferred Reporting Items for Systematic Reviews and Meta-Analyzes" (PRISMA). This study shown that various statistical methods or combination of multivariate statistical methods are used in population genetics. It emerges that there is no a priori a better method, so it is necessary to determine the method adapted to both the data collected and the research objective. This study identified the most commonly used multivariate statistical methods in genetics such as: Ordination methods (52.50%) are methods that summarize the information contained in the data matrix by minimizing wastage. This are: principal components analysis (by 32.0% of the articles), principal coordinates analysis (by 7.50% of the articles), discriminant analysis of principal component, factorial correspondence analysis, factorial discriminant analysis, factorial analysis on distance table. Clustering methods (35%) that aim to form groups of individuals that are as similar as possible, including the hierarchical ascending clustering (17.50% of articles), neighbor-joining, and Bayesian clustering model (by 15% of the articles). The analysis of the molecular variance (7.50%) which consists of studying the intra and inter-population variation and the Mantel test (5%) which aims to test the correlation between the matrix of genetic distances and other distance matrices (environmental causes of genetic variability).