Temporal Variation of Seedling Growth and Leaves Type of Four Morphotypes of Lannea Microcarpa Engl.& K. Krause in Burkina Faso

This study evaluated the growth performance and the leaves type of seedlings from different morphotypes of Lannea microcarpa in the central plateau of Burkina Faso.Then, seeds of Lannea microcarpa were collected from four (4) morphotypes based on their botanical characters and noted as NLs: Lannea sp. from Naab-Mayooghin, MLs: from Mamousyorgo 1, MaLs: fromMamousyorgo2, ZLs: fromZiniaré. One hundred seeds per morphotypes were used for the seedlings production in nursery through sowing by using a randomized block design. The leaves type of the produced seedlings was investigated by visual observation. Significant differences in the growth traits of the seedlings were found among the four morphotypes (p < 0,05). The height and the collar diameter of the seedlings were found to be higher in NLs, MaLs and ZLs than those in MLs. Regarding the leaves, it was observed different types among the morphotypes. Seeds from NLs and MLs produced seedlings with both compound and simple leaves while those from ZLs and MaLs produced seedlings with only compound leaves. Generally, all morphotypes exhibited a relatively high growth with production of different types of leaves

Bacteria-inducing legume nodules involved in the improvement of plant growth, health and nutrition

Bacteria-inducing legume nodules are known as rhizobia and belong to the class Alphaproteobacteria and Betaproteobacteria. They promote the growth and nutrition of their respective legume hosts through atmospheric nitrogen fixation which takes place in the nodules induced in their roots or stems. In addition, rhizobia have other plant growth-promoting mechanisms, mainly solubilization of phosphate and production of indoleacetic acid, ACC deaminase and siderophores. Some of these mechanisms have been reported for strains of rhizobia which are also able to promote the growth of several nonlegumes, such as cereals, oilseeds and vegetables. Less studied are the mechanisms that have the rhizobia to promote the plant health; however, these bacteria are able to exert biocontrol of some phytopathogens and to induce the plant resistance. In this chapter, we revised the available data about the ability of the legume nodule-inducing bacteria for improving the plant growth, health and nutrition of both legumes and nonlegumes. These data showed that rhizobia meet all the requirements of sustainable agriculture to be used as bio-inoculants allowing the total or partial replacement of chemicals used for fertilization or protection of crops

Effect of native arbuscular mycorrhiza fungi inocula on the growth of Cowpea [Vigna unguiculata (L.) Walp.] in three differents agro ecological zones in Burkina Faso

Objective: The use of symbiotic microorganisms as mycorrhizal fungi to improve the availability of nutrients to plants is of great importance in agriculture. In this study, we were interested in the response of cowpea, variety KVX 396-4–5-2D, to mycorrhizal inoculation in the context of selection of effective Arbuscular Mycorrhizal Fungi (AMF) to improve cowpea productivity.Methodology and results: Six native AMF inocula (Talé Mossi, Pissila, Worou 1, Worou 2, Yakouta 1 and Yakouta 2), composed of spores contained in cowpea crop soils, were tested in cowpea plants under greenhouse conditions. Microscopic assessment of mycorrhizal colonization and biomass production were evaluated at the flowering/fruiting stage.Results showed variability among inocula regarding their response to cowpea growth. The frequency of mycorrhizal colonization of inoculated plants was generally high (92%), but the intensities remained low (57.65%). However, Yakouta 2 inoculum has recorded the best frequency (92%) and intensity (57.65%) of mycorrhizal colonization. Inoculation of cowpea with Yakouta 2 inoculum resulted in a significant increase (4 folds) in shoot (3.33 g) and root (1.5 g) biomass compared to control plants (0.5 and 0.3 g respectively for shoot and root biomass).Conclusion and application of findings: From these results, it appears that Yakouta 2 seems to be the most efficient for the growth of cowpea. This generally showed a beneficial effect of inoculation of cowpea suggesting that an endomycorrhizal strain selection could be carried on for cowpea inoculation in situ.Keywords: arbuscular mycorrhizal fungi, inoculation, cowpea, Burkina Fas

Identification of pathogens and monitoring methods for leaf spots disease of shea tree (Vitellaria paradoxa Gaertn. C. F.) in the cropping systems of Komki Ipala (Burkina Faso)

Vitellaria paradoxa is a multipurpose plant species which unfortunately is under multiple pressures causing damages to the plant. This study was to develop methods for monitoring causative agents of shea trees leaf spots in Burkina Faso. An inventory of shea tree individuals and a characterization of leaf spots were performed in Tampoussoumdi, Burkina Faso. Thus, twelve (12) plots of 100 m x 50 m were set up in fallows and fields for identifying all shea trees. Pathogens were also identified by isolated infected leaves fragments of on PDA medium. Isolates were purified and observed under a microscope (X40). As to develop pathogens monitoring methods, three mycorrhizal fungi (yac, fada, Ga) were used to inoculate shea trees cultivated in greenhouse. After two months, inoculated plant leaves were sprayed with prepared isolates of identified pathogens and infection occurrence was checked daily. Results revealed that infection occurred only in unburned fallows and concerned 65% of the shea tree communities. Fungi were found to be responsible for these infections and three species were identified including Fusarium moniliforme, Pestalotia guepini and Phoma sorghina. Results also showed that mycorrhizae can inhibit pathogens growth partially or totally. Their potential use could help controlling the leaf spots disease in shea parks

Evaluation de différentes formulations de compost associés ou non au Tricoderma H. et aux champignons mycorhiziens arbusculaires sur le rendement de la tomate et sur le sol en conditions semi-contrôlées

Dans les systèmes de production maraîchère au Burkina Faso, la pression parasitaire constitue la contrainte majeure, entrainant une réduction importante des rendements. Cela conduit les producteurs à une utilisation non raisonnée et excessive de pesticides chimiques. Ces exploitations maraîchères sont aussi caractérisées par des apports souvent déséquilibrés et excessifs en engrais minéraux. Ces pratiques engendrent ainsi des problèmes d’ordre environnementaux et sanitaires. Afin de contribuer à accroitre durablement la productivité des cultures maraîchères par des pratiques respectueuses de la santé humaine et de l’environnement, une expérimentation a été conduite sur la tomate ( Solanum lycopersicum )en milieu semi-contrôlé en vue d’évaluer différentes pratiques agro-écologiques. Dans un dispositif en split-plot, deux modes de traitement phytosanitaires associés à 7 types de fumure ont été évalués. Les types de fumures sont T1 (30 t/ha de compost seul), T2 (Champignon mycorhizien arbusculaire (CMA) seul), T3 (30 t/ha de compost + CMA), T4 (30 t/ha de compost inoculé au Trichoderma harzianum souche Tabtenga), T5 (30 t/ha de compost inoculé au T. harzianum conditionné par GIE BIOPROTECT), T6 (30 t/ha de compost inoculé au T. harzianum souche Tabtenga + CMA) et T7 (30 t/ha de compost inoculé au T. harzianum conditionné par GIE BIOPROTECT + CMA). La croissance des plants, les biomasses aériennes et racinaires et le rendement en tomates fraîches et sèches ont été évaluées. Les résultats montrent que la vitesse de croissance est plus élevée suite à l’inoculation avec des champignons mycorhyziens ou du Trichoderma comparé au compost seul. De même, l’apport de mycorhize ou de Trichoderma améliore la biomasse aérienne et souterraine comparativement au compost seul pour lequel la production de biomasse était faible. Aucune différence significative n’a été observée entre les traitements mycorhizes et Trichoderma en ce qui concerne la hauteur et de la biomasse sèche mais les traitements T6 et T5 enregistrent respectivement la biomasse fraiche aérienne et racinaire la plus élevée. Il apparait que l’inoculation par des mycorhizes ou diverses souches de Trichoderma permet de stimuler fortement la croissance et la biomasse de tomate. Moyennant une évaluation in situ, ces pratiques pourraient dès lors permettre de réduire voire d’éliminer le recours à des produits de synthèses