Caractérisation agromorphologique des graines de teck (Tectona grandis L. f.) au Bénin

Au Bénin, les plantations de teck jouent un rôle important tant dans le domaine économique que sur le plan environnemental. Malheureusement, la pratique paysanne pour l’installation des plantations consiste à utiliser des semences «tout venant». Cette étude a pour objectif de caractériser sur le plan agronomique et morphologique les graines de teck rencontrées au Bénin afin d’apporter une contribution à l’amélioration de cette pratique paysanne. Pour ce faire, huit sites de collecte ont été choisis à raison d’un par zone agroécologique. Les caractéristiques morphologiques des graines ont été mesurées. La germination et la croissance juvénile ont également été étudiées. Les caractéristiques morphologiques ont permis de distinguer trois catégories de graines. Les essais de germination ont révélé un faible taux de germination. Les graines provenant des zones de terres de barres du Sud (Allada), cotonnières du centre (Savè) et de la dépression (Lama) présentent les meilleurs taux de germination au bout de 50 jours après semis (soit respectivement 37,6% ; 27,8% et 18,0%). L’évaluation du taux de reprise est de 96,35% pour les plants semés en pots contre 94,44% pour ceux semés sur des planches. Dans les meilleures situations (semences traitées provenant des plantations d’Allada), l’accroissement moyen en diamètre en 10 jours est estimé à 0,11 cm pour les plants semés sur des planches et de 0,05 cm pour ceux mis en pot. L’accroissement moyen en hauteur en 10 jours est de 2,77 cm pour des plants semés sur des planches contre 0,44 cm pour ceux mis en pot. Cette connaissance de la variabilité agromorphologique est nécessaire pour les recherches futures sur l’amélioration et la sélection variétale de semences de teck au Bénin.© 2016 International Formulae Group. All rights reserved.Mots clés: Taux de germination, taux de reprise, croissance juvénile, zones agroécologiquesEnglish Title:  Agromorphological characterization of teak seed (Tectona grandis Lf.) in BeninEnglish AbstractIn Benin, teak plantations are important both economically and environmentally. Unfortunately, the farmer practice for installing plantations is to use seed "from everywhere" with no selection. This study aims at characterizing agronomically and morphologically teak seeds found in Benin in order to contribute to improving the farmer practice. Therefore eight collection sites were chosen, with one of each agroecological zone. The morphological characteristics of seeds were measured. Germination and early growth were also  studied. The morphological characteristics allowed to distinguish three categories of seeds. Germination tests revealed a low germination rate. The seeds from areas of ferralitique soils in southern (Allada), in cotton areas of the center (Savè) and depression zone (Lama) have the best germination rate after 50 days from sowing (respectively 37.6%, 27.8% and 18.0%). Evaluation of the recovery rate was 96.35% for the plants sown in jars against 94.44% for those seeded on boards. In the best situations (treated seeds from plantations of Allada), average diameter growth in 10 days is estimated at 0.11 cm for seedlings planted on boards and 0.05 cm for potted. The average increase in height in 10 days is 2.77 cm for seedlings planted on boards against 0.44 cm for potted. This knowledge of the agromorphological variability is necessary for future research on the improvement and variety selection of teak seeds in Benin.© 2016 International Formulae Group. All rights reserved.Keywords: Germination rate, recovery rate, early growth, agro-ecological zone

Résilience à l’insécurité alimentaire des communautés locales de la Réserve de Biosphère de Luki en République Démocratique du Congo

15. Life on lan

Socioeconomic and Cultural Importance of The Yellow-Fronted Canary (Serinus Mozambicus) in Northern Benin

The species yellow-fronted canary undergoes a real traffic due to its song and medico-magical properties in order to supply local commercial networks. This study aims to assess the socioeconomic and cultural importance of this bird in order to identify the cohorts of actors involved along this activity chain. In this context a survey was carried out among 400 breeders in four agroecological zones of Benin (ZAE II; ZAE III, ZAE IV and ZAE V). The questionnaire also focused on general characteristics of the respondents on aspects related to general knowledge of the bird, its social importance, purchase and sale price, cultural importance and breeders’ perceptions. Canary traders, mostly with primary education level (63.25%) and Muslim (97.5%), were on average 44 years old and an average experience of 27 years. They exercised this activity in part-time (96.5%). The knowledge about canary is shared is different depending on the ethnic group. The activity was profitable for all of them (100%) with 128,624 FCFA (233.18 USD) net profit per month. The trader's education level, whether or not he belonged to ZAE II, the number of birds he had in his possession, the daily amount he invested in their food, their selling price, the number of years he made the activity, his experience in the business were the factors that determine the net profit of the canary’s trader. However, canaries' breeding in north-Benin is based on a complex system with actors who develop many myths around medico-magical practices. This study was necessary to better assess the pressure on the species in order to anticipate its conservation

Cutting height as a competition control factor in teak (Tectona grandis L.f) plantations in southern Benin

The effect of stump sprouts on the growth of trees in the main plantation under system of even-aged forest was investigated in this study. In this context, eight plantations taking into account the age, the number of thinning and the type of soil were selected. In order to assess the practices related to cutting height, a survey was carried out in each plantation. In each plantation, at least, two square plots measuring 50 × 50 m (one containing trees with less stump sprouts and the other containing trees with stump sprouts) were installed. The density of stump sprouts and filler trees had a detrimental effect on the growth of trees in the main plantation. Competition for resources was the main cause. The density of stumps and those of filler trees within a radius of 5 m around each future tree were estimated at 3 stumps and 3 filler trees respectively. The distance between the future trees and the stump sprouts or the filler trees was estimated at around 3 m. The search for an appropriate cutting level, spacing of trees and compliance with recommendations related to silvicultural practices are among other solutions to limit this competition