Monthly Archives: mai 2023

KYA Mbaikar^1*3, MANDOU Marie Solange², DONGOCK NGUEMO Delphine³, NOUBISSIE TCHIAGAM Jean Baptiste³

¹Institut Tchadien de Recherche Agronomique pour le Développement (ITRAD). BP.31 Moundou –Tchad

²Département d’Agriculture, Faculté d’Agronomie et des Sciences Agricoles, Université de Dschang

³Laboratoire de Biodiversité et Développement durable (LAB2D) ; Département des Sciences Biologiques. Université de Ngaoundéré (UN). BP. 454 Ngaoundéré, Cameroun

*Auteur Correspondant ; E- mail : mbaikar_kya@yahoo.com; Tél : + 235 66 49 52 61

RESUME

Une étude de l’influence des itinéraires techniques sur la phénologie et le rendement grainier et fruitier de Sesamum indicum L. (Pedaliaceae) a été effectuée à la Station agronomique de Bébédjia (8°40’09” N et 16°54’65” E) au sud du Tchad afin de contribuer à la productivité du sésame. Le dispositif expérimental est un bloc randomisé à quatre répétitions, et quatre traitements (Aucun fertilisant, engrais, compost, compost + engrais). Les résultats ont montré que les phases de croissance végétative, de floraison, de fructification et de maturité du sésame se développent en général mieux dans les parcelles au compost, et à l’engrais + compost que dans la parcelle non fertilisée. Il ressort également que l’engrais + compost améliore significativement le rendement en fruit (93,5 capsules/plant), suivi du compost (86,62 capsules/plant) puis de l’engrais (77,75 capsules/plant). Pour le rendement grains par plant, le compost donne 30,24 g/plant comparé à l’engrais + compost (29,46 g/plant), à l’engrais (24,15 g/plant) et enfin aux parcelles sans fertilisant (19,71 g/plant). Il existe des corrélations linéaires positives (r = 0,82 ; P < 0,05) entre le nombre de capsules par plant et le rendement en grains par plant. Cependant la longueur de feuille et le nombre moyen de capsules par plant sont corrélés négativement (r = – 0,60 ; P < 0,05). L’engrais + compost favorise le développement végétatif en raccourcissant le cycle de production de la plante. La culture du sésame se prête bien au compost à la dose de 3t/ ha qui pourrait être recommandée aux producteurs.

Mots clés : Itinéraires techniques, phénologie, rendements, Sesamum indicum, Tchad

ABSTRACT

A study of technical itineraries influence on phenology and seed and fruit yield of on Sesamum indicum L (Pedaliaceae) was carried out at agronomic Station of Bébédjia (8°40′ 09 ” N and 16°54’65” E) in South Chad in order to contribute to the sesame crop productivity. The experiment design was a complete randomized bloc design and replicated four times with four treatments (without fertilizer, fertilizer, compost, compost + fertilizer). The results showed that the stages of vegetative development, flowering, fructification and maturity of sesame were in general better on plots with compost and fertilizers + compost than the plants in the plots without fertilizer. It was noticed that fertilizer + compost significantly improved the fruit yield (93. 5 fruits/plant) followed by compost (86. 62 fruits/plant) then the fertilizer (77. 75 fruits/plant). For the seed yield per plant, the compost recorded 30. 24 g/plant compared to fertilizer +compost (29. 46 g/plant), the fertilizer (24. 15 g/ plant) and then to the plots without fertilizer (19. 71 g/plant). There are strong positive correlations (r = 0. 82; P < 0. 05) between the number fruits per plant and the seeds yields per plant. However, there is a strong negative correlation between length of leaves and the number of fruits per plant (r = – 0. 60; P < 0. 05). The fertilizer +compost increased the vegetative growth and shortened productive period. The sesame crop grows well with compost at rate 3t/ha that should be recommended to the producers.    

Key words: Technical itineraries, phenology, yields, Sesamum indicum, Chad

^a,Full Professor of Environmental engineering and applied Chemistry, Director of Higher National School of Public Works in Yaounde (ENSTP)

 ^bPhD student in Hydrobiology and Environment

^cDoctors in Hydrobiology and environmental engineering, Part time lecturers in the department of Animal Biology and Physiology, University of Yaounde 1, Cameroon

^d Student of the Higher School of Public Works in Yaounde, specialised in water ressource engineering and management(ENSTP)

^e Full Professor  of hydrobiology, Environmental engineering and Public health

corresponding email : ajeagahg@yahoo.com

ABSTRACT

In order to evaluate the biodiversity of the forms of dissemination of Sarcocystis in the aquatic medium in Yaounde, a study was carried out from January to June 2016. To do so, monthly samplings wer carried out in several points of the Mfoundi stream and in eight marshy areas (Obili, Melen, Mvog-Betsi, Etoug-Ebé, Mokolo Elobie, Tsinga, Ekounou and Nsimeyong). The physico-chemical analyses were done following standard methods and revealed waters with high temperatures (26.61±0.96 ± 0.08 UC), low oxygenation (21.19 ±4, 52%), average mineralization (566.16 ± 182.31µs/cm), rich in suspended matter (23.37 ±06.52 mg/L) and organic matter. On the other hand, biological analyses were made by the observations of oocysts and sporocysts of Sarcocystis spp. using the Olympus brand inverted microscope at the 40x objectives. These observations followed the concentration and coloration of the organisms in the water samples following the Ziehl-Neelsen technique. The results show the presence of 99 oocytsts and sporocysts of Sarcocystis spp. in the Mfoundi stream and 1753 oocysts and sporocysts of Sarcocystis spp. in the marshy areas. Overall, the highest oocysts and sporocyst densities were recorded during the long dry season in the Mfoundi stream and during the short rainy season in the marshy areas. The abundance dynamics of these enteropathogens are significantly and positively correlated with suspended electric conductivity and organic matter (p <0.05). This contamination of water by enteropathogenic protozoa compromises their use as it would constitute a health risk for the populations using these points.

Key words: Dynamics, Sarcocystis, oocysts, sporocysts, physico-chemistry, aquatic me

Asi Quiggle Atud[^1]* and Ajeagah Gideon Aghaindum ^[1]

[1] University of Yaounde I, BP 812, Faculty of Sciences, Animals Biology and Physiology Department, Laboratory of Hydrobiology and Environment, Yaounde city, Cameroon

 * Correspondence:  asiatud@yahoo.com

ABSTRACT

In order to monitor environmental forms of microsporidia in the groundwater of the Centre region of Cameroon, samples were collected from sixteen (16) springs regularly used by the local population. The study was conducted from August 2018 to August 2019 during the four seasons that are characteristized by the ecological bimodal zone of the central south forest of Cameroon. The physico-chemical analysis were carried out both in the field and at the Hydrobiology and Environment laboratory of the University of Yaounde I. Physico-chemical and microbiological parameters were analyzed repectively using standard methods and trichome strain’s. The results of physico-chemical analysis have revealed that springs has an avarege temperature of 25.14 ± 0.73 °C. These water samples are generally poorly mineralized (144.76 ± 104.28 µS/cm), poor in organic matter (2.45 ± 1.06 mg/L) and suspended solids (14.56 ± 12.60 mg/L), but with very high values of turbidity (27.40 ± 28.16 FTU). The physico-chemical results showed that these areas are poorly polluted with low anthropogenic impacts.  Microbiological analysis, showed contamination of groundwater with microsporidia spores unfit for drinking. The observations revealed several shapes of spores in the environment in relation to their sizes (μm) leading to species richness. Statistical analysis showed variations in spores between stations and seasons with a higher abundance during rainy season. Findings, showed diversity of species in the water  Enterocytozoon bieneusi (1-1.6 x 0.7-1.2), (Encephalitozoon intestinalis (1.8-2.4 x 1.2-2.0), Encephalitozoon hellem (2-2.5 x 1.6-2), Encephalitozoon cuniculi (2.8-3.2 x 1.6-2.4) , Nosema spp. (3.2-3.6x 2-2.4 ), Vittaforma corneae (3.6 – 4 x 1.2-1.6 ), Pleistophora spp. (3.2-4x 2-2.4), and Microsporidium spp. (2.8-4.4 x 1.6-3.2). These spores would be better appreciated by molecular analysis. These results showed that, microsporidian spores are diverses and ubiquitous indicating a poor quality of water and good indicator to assess water quality.

Keywords: Biomonitoring, Spores, Drinking water, Physico-chemical, Health risk, Springs 

Nkeng George Elambo^a, Djoudjo Yolande^b, Tsoméné Namekong Pierre^c, Asi Quiggle Atud^c, Mbouombouo mama^c ,Badjika Goldin^d, Ajeagah Gideon Aghaindum^e

^a,Full Professor of Environmental engineering and applied Chemistry, Director of Higher National School of Public Works in Yaounde (ENSTP)

 ^bPhD student in Hydrobiology and Environment

^cDoctors in Hydrobiology and environmental engineering, Part time lecturers in the department of Animal Biology and Physiology, University of Yaounde 1, Cameroon

^d Student of the Higher School of Public Works in Yaounde, specialised in water ressource engineering and management(ENSTP)

^e Full Professor  of hydrobiology, Environmental engineering and Public health

corresponding email : ajeagahg@yahoo.com

ABSTRACT

In order to evaluate the biodiversity of the forms of dissemination of Sarcocystis in the aquatic medium in Yaounde, a study was carried out from January to June 2016. To do so, monthly samplings wer carried out in several points of the Mfoundi stream and in eight marshy areas (Obili, Melen, Mvog-Betsi, Etoug-Ebé, Mokolo Elobie, Tsinga, Ekounou and Nsimeyong). The physico-chemical analyses were done following standard methods and revealed waters with high temperatures (26.61±0.96 ± 0.08 UC), low oxygenation (21.19 ±4, 52%), average mineralization (566.16 ± 182.31µs/cm), rich in suspended matter (23.37 ±06.52 mg/L) and organic matter. On the other hand, biological analyses were made by the observations of oocysts and sporocysts of Sarcocystis spp. using the Olympus brand inverted microscope at the 40x objectives. These observations followed the concentration and coloration of the organisms in the water samples following the Ziehl-Neelsen technique. The results show the presence of 99 oocytsts and sporocysts of Sarcocystis spp. in the Mfoundi stream and 1753 oocysts and sporocysts of Sarcocystis spp. in the marshy areas. Overall, the highest oocysts and sporocyst densities were recorded during the long dry season in the Mfoundi stream and during the short rainy season in the marshy areas. The abundance dynamics of these enteropathogens are significantly and positively correlated with suspended electric conductivity and organic matter (p <0.05). This contamination of water by enteropathogenic protozoa compromises their use as it would constitute a health risk for the populations using these points.

Key words: Dynamics, Sarcocystis, oocysts, sporocysts, physico-chemistry, aquatic me