Parasitic nematodes have been reported as one of the major constraints to soybean production worldwide. The majority of nematodes are so-called "freeliving" and feed mainly on bacteria, fungi, protozoa and other nematodes. In Burkina Faso, the presence of parasitic nematodes has been reported in crops such as rice and sorghum. The objective of this study was to identify the genera and species of nematodes associated with soybean production in Burkina Faso. Investigations were carried out on 24 genotypes of a medium-maturity group of soybean at the Farako-Ba research station. Soil samples were taken from the trial soil before its installation. At harvest, soil samples with roots were taken from each genotype in the elementary plots. The composite sample is represented by 4 lots of soil samples with roots. Extractions and counts of nematodes were performed on the different lots. In total, 7 genera of plantparasitic nematodes associated with soybean were identified. Among these genera, Pratylenchus (100% of infected genotypes), Helicotylenchus (97.28%) and Scutellonema (94.44%) were the most prevalent in terms of frequency and abundance. Some soybean genotypes were less susceptible to the genus Pratylenchus is known to be highly pathogenic in soybean. These were mainly the genotypes TGX2025-10E, TGX2023-3E and TGX2025-14E.

Soybean is one of the promising food crops and feeds which contributes significantly to the development of agriculture in Burkina Faso. However, very few improved soybean varieties have been developed in the country. The introduction of new genotypes with high agronomic potential and adapted to the climatic conditions of the Sudanian zone of Burkina Faso will boost soybean production in the region. Twenty-four (24) newly introduced soybean genotypes were evaluated for their agromorphological and adaptation characteristics in the Sudanian zone of Burkina Faso. The variability parameters such as genotypic and phenotypic coefficient of variation, broad sense heritability, and expected genetic advance were estimated for 14 agromorphological characters. The experimental design used in this study was an alpha lattice with 3 replications. Planting was done following a spacing of 50 cm (inter-row) × 5 cm (within row). Analysis of variance revealed significant difference ( P < 0.001 ; P < 0.05 ) for all characters studied except the nodule diameter, nodule score, and grain yield. The values of the phenotypic coefficient of variation (PCV) were higher than genotypic coefficient of variation (GCV) for all the characters indicating the influence of environmental factors. The highest GCV and PVC values were found in the number of nodules (70.07% and 77.26%), number of seeds per plant (41.34% and 44.18%), and number of pods per plant (29.27% and 33.50%), respectively. High estimates of heritability coupled with high genetic advance expressed as a percentage of mean were observed for 10 of the 14 traits, suggesting an important expected genetic gain allowing more success in selection.