Kihindo et al., J. Appl. Biosci. 2016.Variation de la réponse physiologique et agronomique du niébé (Vigna unguiculata L.Walp) à différentes dates de semis au Burkina Faso.

Okra (Abelmoschus esculentus), a fruit vegetable consumed in several countries, especially in Africa, contributes to the fight against poverty and malnutrition due to its nutritional value. However, in Burkina Faso, its cultivation during the dry season that lasts about 9 months remains dependent on the availability of water resources. Thus, during this period that lasts about 9 months, because of this situation, okra producers are dealing with very diversified sources of water. However, the rehydration of seeds, which is the first step towards germination, depends mainly of the water. Therefore, the aim of the present study was to test the germinability of okra seeds under different irrigation waters in order to propose alternative sources. Thus, seeds of three ecotypes of okra (B2, G259, and L2) were germinated using five water types (dam water, wastewater from the sewage treatment plant (WTP), well water, dishwashing greywater, and distilled water). The results showed a significant influence of the water type on the germination velocity and the growth speed of the radicle. Indeed, using wastewater from the WTP, the germination velocity was very significantly lower than those obtained with the other sources (P<0.0001). Furthermore, seeds irrigated with WTP wastewater germinated less than other water types. Nevertheless, the germination rate obtained with dishwashing greywater (86.93 ± 0.14%), which is not used generally in agricultural production, is comparable to the rates obtained with other water types. Furthermore, the study showed a significant effect of the ecotype on the germination rate (P≤0.001). In addition, dam water significantly enhanced root growth compared to WTP (P<0.0001). In view of the results and because of water scarcity in Sahelian regions, dishwashing greywater, which is generally discarded, could be collected and used for the germination of okra.

Mung bean (Vigna radiata) is grown throughout the world thanks to its short cycle, its great adaptability to climatic conditions and its good digestibility. In Burkina Faso, agriculture is faced with irregular rainfalls, resulting in water stress on plants causing growth and yields reduction. This study aims at identifying supplemental irrigation frequencies that help good mung bean plant to grow and yield. So, four watering schemes were applied to plants aged 26 days, grown in pots on a sandy and silty substrate, in natural conditions of light and temperature during the wet season. The watering regimes concerned a batch of plants watered only by rain (0 day scheme) and three other batches, each watered with tap water in the absence of rain respectively every 5 days, every 10 days and every 15 days. A completely randomized three-replicate block system was set up and agro-morphology parameters were measured. The study showed that the 5 days diet resulted in plants with better growth and good pod yields compared to other watering schemes. These results confirm that supplemental irrigation applied early during drought po0063kets is resilience to the irregularity of rains in the wet season, which is accentuated by climate change.

Jatropha curcas is a highly promising species for biodiesel production in Burkina Faso and other countries in the tropics. It is rustic, grows in warm regions and is easily cultivated. These characteristics and high-quality oil yields from the seeds have made it a priority for biodiesel programs. Consequently, this plant merits genetic investigations aimed at improving yields. The present study was conducted to determine the extent of genetic variability and relationships among 30 accessions from Burkina Faso using 7 qualitative characters and 20 quantitative characters. For most of the traits, there were highly significant differences among the accessions. A positive and significant correlation between the 100-seed weight trait and the oil content trait was observed. The oil content trait is significantly and positively influenced by growth traits such as plant height and crown diameter. Based on the petiole base pigmentation, three morphotypes were identified: green morphotype, purple morphotype and brown morphotype. The green morphotype was characterized by very high oil content and high 100-seed weight while the brown morphotype presents low oil content and low 100-seed weight. The purple morphotype registered a high oil content and medium 100-seed weight. These results are important for the continuity of breeding programs, aimed at obtaining cultivars with high grain yield and high oil content in seeds.