Essais de germination et suivi des performances de croissance des plants de Khaya senegalensis (Desv.) A. Juss., en zone soudanienne (Côte d’Ivoire)

Khaya senegalensis (Acajou de savane) est une espèce de bois d’œuvre couramment exploitée abusivement dans les zones soudaniennes de la Côte d’Ivoire. Cette étude, visant à améliorer la domestication de l’espèce, a testé deux modes de multiplication, l’une utilisant directement les graines et l’autre des portions de tiges pourvues de système racinaire appelées « stumps ». Le matériel de propagation a été collecté sur des sujets de l’espèce puis soumis à l’influence de facteurs abiotiques (intensité de l’ensoleillement, profondeur de semis, types de sols). Les résultats ont montré que les graines traitées à l’eau présentent de bonnes qualités germinatives avec des taux de germination de l’ordre de 80 %, une énergie germinative d’au moins 50 % et une valeur culturale pouvant atteindre 80 %, que cela soit en milieu ombragé ou milieu ensoleillé. Concernant la variation de la profondeur de semis sur les paramètres de germination, les graines de K. senegalensis produisent les meilleurs résultats de germination pour des profondeurs de semis de 1 à 3 cm. La croissance des plants issus de stumps atteint une hauteur de 35 cm contre 28 cm pour les plants issus de graines, en milieu ombragé. Ainsi, la reproduction par voie de stumps présente une technique supplémentaire à la production de plants en pépinière pour le reboisement de l’espèce. ABSTRACT Khaya senegalensis (Savannah mahogany) is a timber species commonly exploited nowadays in the Sudanese areas of Côte d’Ivoire. This study aimed at improving the domestication of the species tested two modes of propagation, one using the seeds directly and the other portions of stems provided with a root system called "stumps". Propagation material was collected from subjects of the species and then exposed to the influence of abiotic factors (intensity of sunshine, depth of sowing, types of soil). The results have shown that the seeds treated with water have good germination qualities with germination rates of the order of 80 %, a germination energy of at least 50 % and a cultural value of up to 80 %, than either in shaded or sunny surroundings. Regarding the variation of the sowing depth on the germination parameters, the seeds of Khaya senegalensis produce the best germination results for sowing depths of 1 to 3 cm. The growth of the plants resulting from stumps reaches a height of 35 cm against 28 cm for the plants resulting from seeds, in shaded environment. So, reproduction by means of stumps presents an additional technique to the production of seedlings in the nursery for the reforestation of the species.

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Germination Test of Shea Seeds (Vitellaria paradoxa C.F. Gaertn) in Nursery on Substrates of Northern Côte d’Ivoire

Asian Plant Research Journal ◽

10.9734/aprj/2019/v3i230064 ◽

2020 ◽

pp. 1-13

Author(s):

Alui Konan Alphonse ◽

Diarrassouba Nafan ◽

Yao Saraka Didier Martial

Keyword(s):

Cote D'ivoire ◽

Côte D’Ivoire ◽

Abiotic Factors ◽

Germination Rate ◽

Organic Fertilization ◽

Cote D’Ivoire ◽

Côte D'ivoire ◽

Two Factors ◽

Shea Tree

Aims: The present study aims to evaluate the effect of some abiotic factors on the quality of seed germination of shea tree, a plant of great economic interest for the rural populations in Northern Côte d'Ivoire. Study Design: The trials were conducted in a nursery where two factors were considered. These were the substrate, with six modalities and shelter with two modalities. Six small pits, each of size 60 x 60 cm, surface 3600 cm2 and 15 cm of depth were dug and then filled with different substrates. Place and Duration of Study: The work was carried out in 2018 in the district of Korhogo in Northern Côte d'Ivoire. Methodology: Each treatment received 36 seeds of shea tree giving a total of 216 seeds per test. The seeds used were all dark brown, ellipsoid in shape with masses ranging from 10 to 11 g. The experiment was carried out with a total of 12 treatments, six under a greenhouse hermetically covered with transparent polyethylene plastic and six under a shade made up of a rack covered with maximum Panicum leaves. Results: The first germination was observed at the level of the organic manure treatment at 6 months of degradation installed under the greenhouse (ManB_G = 28 days). The lowest final germination rate was obtained with the organic fertilization at 3 months of degradation installed under the shade (FGP ManA_S = 2.95%) while the highest was observed in the sawdust installed under the greenhouse (FGP S_G = 64.18%). Conclusion: It is concluded that for each substrate, soil or biowaste, the seeds of shea tree have a better ability to germinate under a greenhouse than under a shelter covered with straw.

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Process of Attack on Cashew Tree Branches by Diastocera trifasciata (Coleoptera: Cerambycidae) and the Relationship between These Attacks and the Phenological Stages in the Gbêkê Region (Central Côte d’Ivoire)

Insects ◽

10.3390/insects11080456 ◽

2020 ◽

Vol 11 (8) ◽

pp. 456

Author(s):

San-Whouly M. Ouali-N’Goran ◽

Ettien Narcice Akessé ◽

Gniré Mariam Ouattara ◽

Daouda Koné

Keyword(s):

Cote D'ivoire ◽

Côte D’Ivoire ◽

Control Method ◽

Abiotic Factors ◽

Growth Stages ◽

Phenological Stages ◽

Cote D’Ivoire ◽

Average Temperature ◽

Côte D'ivoire ◽

Cashew Tree

Cerambycidae Diastocera trifasciata attacks were studied from October 2015 to September 2017 in three cashew tree orchards in the locality of Brobo in central Côte d’Ivoire. One hundred fifty-three (153) cashew trees, arranged on a diagonal from each orchard, were selected for sampling. The attacked plants and the branches cut per tree were counted every 15 days. Biotic parameters, namely phenological stages of trees, and abiotic factors, which are rainfall, relative humidity and average temperature, were recorded throughout the study. Attacks were observed from mid-September to January from the pre-flowering vegetative stage to the flowering stage. Attack period duration was therefore four and a half months per year. The peak of attacks was recorded in November with an attack rate of 88.02% in 2015 and 75.49% in 2016. No attack was recorded from February to mid-September, corresponding to the flowering, fruiting and post-harvest vegetative growth stages. This description of the attack process and the determination of D. trifasciata attack periods provides essential data for the implementation of an effective and sustainable control method of this species.

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Effet des durées de conservation et du traitement à l’eau sur la germination des graines de Tieghemella heckelii Pierre ex A. Chev. (Sapotaceae) en Côte d’Ivoire

International Journal of Biological and Chemical Sciences ◽

10.4314/ijbcs.v14i8.18 ◽

2020 ◽

Vol 14 (8) ◽

pp. 2880-2892

Author(s):

Kouassi Kouadio ◽

Souleymane Sanogo ◽

Edouard Konan Kouassi ◽

Cybèle Sopie Doffou

Keyword(s):

Cote D'ivoire ◽

Côte D’Ivoire ◽

Tap Water ◽

Germination Rate ◽

Time Limit ◽

Timber Species ◽

Cote D’Ivoire ◽

Germination Time ◽

Côte D'ivoire ◽

Germination Parameters

Le Makoré est une espèce de bois d’oeuvre de grande valeur commerciale, en danger de disparition dans les forêts tropicales. Cependant, la germination des graines fraiches et celles séchées et conservées est peu connue par l’homme. C’est pourquoi, cette étude vise à maitriser les paramètres de germination des graines de Makoré, afin de l’utiliser dans les reboisements des forêts classées en Côte d’Ivoire, en vue de sa pérennisation. Spécifiquement, il a été question de déterminer le délai de germination, la durée de germination et le taux de germination des graines. Pour ce faire, 5 lots de graines ont été constitués en fonction des durées de conservation sur lesquels 4 traitements à l’eau de robinet ont été appliqués. Les résultats ont montré que le lot 1 ou témoin (graines fraiches), le lot 2 (graines conservées pendant 14 jours) et le lot 3 (graines conservées pendant 21 jours) ont présenté des taux de germination, respectivement, de l’ordre de 72, 22, 55,56 et 41,67%. Le trempage des graines dans l’eau de robinet a réduit considérablement le délai de germination des graines du lot 1 à 25 jours et a relevé le taux de germination du prétraitement 4 du lot 1 (graines ayant séjourné dans l’eau pendant 6 jours) à 100%. Il ressort de cette étude que pour produire des plants de Makoré, les graines fraiches et celles séchées et conservées pendant deux et trois semaines peuvent être utilisées.Mots clés: Makoré, espèce menacée, conservation des graines, prétraitement, paramètres de germination, Côte d’Ivoire. English Title: Effect of storage times and water treatment on germination of the seeds of Tieghemella heckelii Pierre ex A. Chev. (Sapotaceae) in Côte d’Ivoire Makoré is a timber species of great commercial value, in danger of disappearing in tropical forests. However, the germination of fresh seeds and those dried and preserved is little known by man. That is why, this study aims to control the seeds germination parameters of Makoré, in order to use it in the reforestation of the classified forests in Côte d’Ivoire, with a view to its perpetuation. Specifically, there has been talk of determining germination time limit, germination duration and seed germination rate. To do this, 5 lots of seeds were constituted according to the storage periods on which 4 treatments with tap water were applied. The results showed that the lot 1 or control (fresh seeds), lot 2 (seeds stored for 14 days) and lot 3 (seeds stored for 21 days) showed germination rates, respectively, of the order of 72.22, 55.56 and 41.67%. Soaking of the seeds in the tap water significantly reduced the germination time limit of seeds from lot 1 to 25 days and increased the germination rate of pretreatment 4 of lot 1 (seeds having remained in water for 6 days) 100%. This study shows to produce seedlings, fresh seeds and those dried and stored for two and three weeks can be used.Keywords: Tieghemella heckelii, threatened species, storage seeds, pretreatment, germination parameters, Côte d’Ivoire.

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