The objective of this study was to evaluate, in a semi-controlled environment, the resistance of twelve (12) new rice genotypes (KBR2, KBR4, KBR6, KBR8, KBR9, KBR11, KBR12, KBR13, KBR15, KBR17, KBR28, KBR42) to rice blast caused by Magnaporthe oryzae in Burkina Faso. The experimental design used was a randomised block with three (03) replications. The parameters assessed were leaf and panicle severity, leaf and panicle incidence, yield per pot and percentage yield loss. The results showed that genotypes KBR11, KBR15 and KBR42 were resistant to medium resistance to blast, with values ranging from 7.7% to 15% of leaf area diseased and from 14% to 24.07% of panicles diseased. These genotypes recorded the best yields per pot of 60.32g/pot, 65.97g/pot and 60.43g/pot respectively, with relatively low yield losses. Genotypes KBR11, KBR15 and KBR42 were resistant to medium resistance to leaf and panicle blast with high yield performance and relatively low yield loss rates. These genotypes can be used to control rice blast in rice fields in Burkina Faso. They therefore need to be improved and made more widely available. This will require the support of agricultural research, extension services and farm advisory services.

In Côte d’Ivoire, the base layers on road are generally made from lateritic soils which must respect specification in order to guarantee its quality. Unfortunately, most of the road bases made with lateritic soils from the sedimentary basin degrade early. This investigation aims to determine the geotechnical characteristics of the natural lateritic soils from sedimentary basin used for road construction to understand the reasons for their early degradation. Thus, soils from Songon and Samo were subjected to tests, to know their intrinsic properties. Particle size distribution, Atterberg limits and methylene blue test, modified Proctor, California Bearing Ratio (CBR), and chemical and mineralogical tests were performed. The soils of Samo and Songon contain appreciable quantities of iron and aluminum oxides and silica, but small quantities of titane, manganese and magnesium oxides. They are mainly composed of kaolinite and quartz. Furthermore, they are massive consisted of sand packed in fine matrix (49 % and 46 %) for soil of Samo and (62 % and 33 %) for soil of Songon but no gravel. The dry densities, the optimum moisture content and CBR at 95 % of maximum dry density obtained for the soil of Samo and Songon are respectively 1.83; 15.2 %, 24 % and 1.88; 16.7 %, 20 %. These soils are not suitable for use as base layers on road because they are still in a primary stage of lateritic soils formation.