scholarly journals 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 ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 456
Author(s):  
San-Whouly M. Ouali-N’Goran ◽  
Ettien Narcice Akessé ◽  
Gniré Mariam Ouattara ◽  
Daouda Koné

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.

2020 ◽  
pp. 1-13
Author(s):  
Alui Konan Alphonse ◽  
Diarrassouba Nafan ◽  
Yao Saraka Didier Martial

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.


2021 ◽  
Vol 48 (2) ◽  
pp. 8673-8685
Author(s):  
Pagadjovongo Adama SILUE ◽  
Kouadio Arsène Dieudonné KOFFI KOFFI ◽  
Adjoua Bénédicte KOFFI ◽  
Konan Edouard KOUASSI

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.


Author(s):  
Brou Kouassi Guy ◽  
Silue Souleymane ◽  
Doga Dabé ◽  
Oro Zokou Franck ◽  
N’goran Yao Claude François ◽  
...  

Cashew cultivation faces several health problems. Among these problems, anthracnose causes extensive damage to twigs, leaves and fruits and causes loss of yield. The spread of this disease is thought to be determined by certain agromorphological features of the cashew tree. The objective of this study was to search for these agro-morphological determinants that influence the spread of anthracnose disease in agroforestry systems in Côte d'Ivoire. To achieve this objective, 30 cashew trees spread across 26 agroforestry cashew orchards in the Korhogo, Sinématiali and Boundiali departments were chosen and geolocated. The factor studied was the clone, consisting of 30 cashew genotypes, with 15 modalities. The collected data was subjected to descriptive analysis, correlation test, PCA and hierarchical ascending classification (CAH). The results showed that the wingspan, leaf area and size of cashew trees are determinants that promote the spread of anthracnose disease. Following this result, the CAH made it possible to screen the genotypes into three groups. These results could contribute to management of anthracnose disease in agroforestry, to enhance and intensify this cropping systems.


Author(s):  
Yadom Y. F. R. Kouakou ◽  
Kouamé Daniel Kra ◽  
Hortense Atta Diallo

The telluric factors favorable to nematode pathogenic diversity make yam nematode control ineffective. This work aims at studying the fluctuation in yam nematodes depending on yam phenological stages. Trials were implemented in four yam production areas in Côte d'Ivoire. After inventory of symptoms on yam tubers, the nematodes associated with the symptoms were extracted and identified. The correlation coefficients between the severity of symptoms on tubers and the size of the associated nematode populations were determined. The size of nematode populations associated with the symptoms were determined in 100 g of soil and 100 g of yam peel were determined depending on the phenological stages of yam plants. Galls, cracks, dry and wet rot were observed on harvested yam tubers. Globodera, Meloidogyne spp., Pratylenchus coffeae and Xiphinema were the nematodes associated with the symptoms. Pratylenchus coffeae was strongly involved in the development of cracks (r = 0.75) and dry rot (r = 0.86) then Meloidogyne spp. in that of galls (r = 0.78). Pratylenchus coffeae and Meloidogyne spp. fluctuation in cultivation soils and yam tubers is influenced by yam phenological stages. Their numbers increase in soils and tubers before tuberization initiation. Producers could draw on the results of this study to establish a schedule of nematicide treatments that could start as soon as yam seeds are planted.


2019 ◽  
Vol 13 (4) ◽  
pp. 369-374
Author(s):  
A. Yao ◽  
A. Hué ◽  
J. Danho ◽  
P. Koffi-Dago ◽  
M. Sanogo ◽  
...  

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