Phytochemical Composition and Insecticidal Property of Native Plants against the Cowpea Weevil Callosobruchus maculatus Fab. (Coleoptera: Bruchidae) for Natural Preservation of Cowpea Seeds

About 80% of cowpea seeds are lost along with 30% of their weight after six months of unprotected storage due to attacks by Callosobruchus maculatus. This study aimed at evaluating the effect of applying bioinsecticides on the biological parameters of C. maculatus to reduce its damage to cowpea stocks. Four treatments including an untreated control and three doses of powdery extracts of C. nigricans, Z. zanthoxyloides and H. suaveolens, were compared in a Fischer block with four completely randomized repetitions. One hundred undamaged cowpea seeds were mixed with doses of each extract in Petri dishes and then fed as food substrates to ten pairs of C. maculatus for eight days. The extracts of H. suaveolens, C. nigricans and Z. zanthoxyloides all contain active ingredients including polyphenols, flavonoids, anthocyanins and alkaloids, etc. The extract of Z. zanthoxyloides was found to be more active on adults (100.00% mortality) followed by C. nigricans (98.75% mortality) and H. suaveolens (97.50% mortality) at 80 mg/g. Fecundity per female decreased significantly in the treated batches of 13.82 eggs for H. suaveolens at 10.12 eggs for C. nigricans at a dose of 80 mg/g. Germination rate of seeds was statistically raised to 100% at 60 and 80 mg/g by C. nigricans powder and lowered to 83.00% at 20 mg/g by Z. zanthoxyloides extracts. The application of Z. zanthoxyloides extract would be a less expensive alternative for the sustainable management of C. maculatus in cowpea stocks.

Efficacy of Botanicals on Parasitoids of Mango Fruit Flies in Burkina Faso

The effect of Capsicum annuum and Strophantus hispidus formulations was evaluated on Diachasmimorpha longicaudata. The formulations were obtained from the crude total extracts of C. annuum;S. hispidus and the adjuvant previously developed. The formulations were prepared according to three concentrations of extracts of each plant species (low, medium and high). These concentrations were calculated on the basis of 1.5 mg/mL of each formulation causing 18% and 15% mortality respectively in Ceratitis cosyra within 72 h. The effect of the formulations on D. longicaudata was tested using a Fisher block design with 8 treatments (C. annuum (3.75;7.5;12.5 g/L);S. hispidus (4.5;9;15 g/L);Success bait 2.4 g/L;control) and 5 replicates. For each formulation, 1.5 mL was poured into a vial containing 0.25 g of cotton. Then 20 adults of the parasitoid were added and the whole was covered with muslin and held in place with rubber bands. The parasitoids were examined after 24 and 72 hours, and those that did not react to the touch of a fine brush were considered dead. The results showed a difference between the treatments. After 24 hours of exposure, the parasitoid showed high mortality at the S. hispidus concentrations (15 g/L;4.5 g/L) followed by the Success bait. These concentrations resulted in mortality rates of 22.50% for S. hispidus and 20.50% for Success bait. After 72 h, low parasitoid mortality (35.81%) was obtained with 3.75 g/L C. annuum, but high mortality was observed with S. hispidus (59.95%;64.20%;57.15%) and Success bait (54.80%). The use of C. annuum formulations at 3.75 g/L could be recommended for conserving D. longicaudata in the nature.

Effects of Direct Sowing under Mulch-Based Cropping System (DMC) on Cotton and Maize Yield and Chemical Characteristics of Ferruginous Soil (Lixisoil) in the South Sudan Area of Burkina Faso

To better understand the effects of direct sowing under mulch-based cropping system (DMC) in Burkina Faso’s cotton production systems, randomized blocks of Fisher experimental design were implemented at Farako-Ba research station from 2010 to 2019. The study was conducted on lixisoil to evaluate DMC effects on biomass production, crops yields and soil chemical properties in a maize and cotton rotation system associated with cover crop. Conventional tillage and direct seeding without cover crop were compared to DMC under B. ruziziensis (GERM. & EVRARD), DMC under B. ruziziensis + M. cochinchinensis mulch and DMC under C. juncea (L.) mulch used in association with maize. Biomass production, crop yields and soil chemistry were evaluated. Results showed that over 10 years, no-till with or without a cover crop provided cotton seed and maize yields that were statistically equivalent to the tillage commonly practiced by farmers. Cover crop has allowed increasing the biomass production compared to Conventional Tillage and Direct Seeding. Maize yield has not varied significantly with the cover crop. After 10 years of maize and cotton rotation, the improvement raised from +27% to +38% for organic matter and from +15% to +29% for nitrogen with DMC including legumes such as M. cochinchinensis and C. juncea compared to Conventional Tillage on 0 - 5 cm depth. No significant differences were found on soil pH like P2O5 and K2O content. Although DMC with C. juncea used as cover crop did not provide the best biomass production, it contributes to increase nitrogen and organic matter and presents better mineral balances in 10 years of rotation. The 5 - 10 cm and 10 - 20 cm were little influenced by DMC systems.

Comparison of Proximate Composition and Nutritional Qualities of Fifty-Three Cashew Accessions from Burkina Faso

Cashew cultivation is growing in Burkina Faso, but nut production remains low. Identification of high-performance plant material with known varietal characteristics is essential for breeding. This study consisted of physical-chemical and nutritional characterization of almonds from a core selection of 53 cashew accessions from Burkina Faso. Proximate composition included contents in water, lipids, carbohydrates, proteins, ash, cellulose using standard methods. Major constituents were lipids with an average level of 50.71% ± 4.07%, followed by carbohydrates and proteins with average levels of 21.18% ± 3.81% and 20.62% ± 1.58%, respectively. Average water, ash and cellulose levels were 4.56% ± 0.39%, 2.87% ± 0.27% and 4.61% ± 2.52%, respectively. The analysis of variability within accessions, based on physical and chemical parameters, identified 3 groups that differ in lipids, carbohydrates, proteins, cellulose and energy value. The first group containing 17 accessions of fat-rich cashews, average protein levels and very high energy values is more interesting for tree improvement programs.

Agricultural Soil Fertilizing Potential of Dry Faecal Sludge from Treatment Plants in Burkina Faso

The dry faecal sludge (DFS) are potential sources of organic fertilizers because of their high content in nutrients and organic matter, critical for plants growth and soil health maintaining. In Burkina Faso, the DFS are processed in faecal treatment plants. However, after drying, the DFS are most often dumped in the nature without any control or directly used as fertilizer without any idea of their potential risks for human health and the environment. This investigation aimed at physico-chemical and toxicological characterization of the DFS from faecal treatment plants according to the duration of their storage. For this purpose, DFS samples were collected in three (3) faecal treatment plants in Ouagadougou and one in Bobo Dioulasso, in Burkina Faso. The measurements were carried out on pH (H2O), organic matter content, major nutrients (N, P, K), trace elements (Na, Ca and Mg) and metallic trace elements. Indifferently to the faecal treatment plants and the duration of the storage, the DFS showed strong acidity (4.85 ± 0.13 et 6.53 ± 0.10) and low content in total elements (Na à40.97% ± 9.99%). Values recorded of the trace metallic elements showed there were no risk of contamination when used as fertilizers: (103.9 ± 2.00 mg/kg < Cu < 137 ± 25.69 mg/kg);(710.13 ± 18.97 mg/kg < Zn < 922.30 ± 7.04 mg/kg);(33.03 ± 1.65 mg/kg < Pb < 152.40 ± 19.40 mg/kg);(1.34 ± 0.17 mg/kg < Cd < 1.76 ± 0.04 mg/kg);(34.34 ± 0.27 mg/kg < Ni < 52.32 ± 3.60 mg/kg) et (771.15 ± 18.36 mg/kg < Cr < 1697.83 ± 55.11 mg/kg). The results indicated a high fertilizer potential of the DFS after addressing the issue of their acidity.

Mitigating Iron Toxicity by Using Rock Phosphate to Improve Rice Productivity

Iron toxicity is a major constraint to rice production, particularly in highly weathered soils of inland valleys in Sub-Saharan Africa where the rice growing area is rapidly expanding. This study aimed to improve the productiveness of iron toxicity sensitive’s rice fields as well as in the unsensitive fields by using local phosphate fertilizers. Eighteen (18) rice genotypes were been assessed in a split plot design in two areas: without iron toxicity and with iron toxicity. NPK, NK, Rock Phosphate, Triple super phosphate, Calcined phosphate and Acidulated phosphate were used as fertilizers. Data collection was focused on agronomic traits and yield (g/m2). The best fertilizers in the area without iron toxicity were NPK (820.2 g/m2) and triple super phosphate (751.7 g/m2). In the iron toxicity area, the best yields were performed by NPK (785.5 g/m2) and raw calcined phosphate (698.3 g/m2). Yet, the Accessions 15, Accessions 225, Accessions 226 and Accessions 270 were rainfed rice genotypes while CC109 A, HB 46 and HB 62 were low-land/irrigated rice genotypes. NPK, NK and acidulated phosphate fertilizers alleviate the best, iron toxicity in both sensitive and unsensitive rice fields.