The current low recruitment rate of the exploitable tree species arouses silvicultural interventions for long-term management of their populations. This study evaluated the germination of the Erythrophleum suaveolens seeds in nursery following different pretreatments. The seeds have been collected under seed trees of E. suaveolens chosen in a range from 30 to 155 cm North Congo in the Celtis forest within a plot of 400 ha on clay-sandy to sandy-clay soils. A complete design randomized of two blocks has been establish in the greenhouse at respective average temperature and humidity of 24°C and 60%. The seed lot (350 seeds) has been divided into seven treatments for to test the modalities of breaking dormancy, at the rate of 50 seeds per treatment. The dormancy of the collected seeds was lifted by germination tests after treatment with sulfuric acid (H2SO4), in an oven at 140°C and in the boiling water. The seeds have been individually and immediately sowed after treatments. The germination rates were 68-76%, 36-56%, 16% and 12-28%, respectively for the T2, T1, T5 and T6 treatments, with germination times of 6 days for T1 and T2, 15 days for T5 and 15-20 days for T6. Treatments T3, T4 and T7 presented zero germination rates. The factors that can influence seeds variations of germination are discussed and recommendations inherent in the considerable efforts of assisted regeneration of this species which occupies a preponderant place in logging in Central Africa are formulated.
Le maraîchage urbain joue un rôle très important dans la sécurité alimentaire et la résorption du chômage. Cependant, l’intensification des pratiques culturales peuvent altérer les propriétés physicochimiques des sols et réduire les rendements. La présente étude avait pour but de caractériser les pratiques culturales maraîchères à Brazzaville et de déterminer leur influence sur les propriétés physicochimiques des sols. Dans les sites retenus, des enquêtes structurées ont été menées auprès des maraîchers et des échantillons de sol ont été prélevés suivant des transects. Les analyses physiques et chimiques des sols ont été réalisées suivant les procédures courantes de laboratoire. Les résultats obtenus ont montré que les pratiques culturales dans les sites étudiés sont intensives. Les sols étudiés sont sableux à plus de 95%, acides, pauvres en matière organique et ont une CEC relativement faibles. Cependant on relève une sursaturation en bases échangeables sur l’ensemble des sites. Ainsi, cette sursaturation serait liée à l’intensification des pratiques culturales. Urban market gardening plays a very important role in food security and the reduction of unemployment. However, intensification of soil use can alter soil properties and reduce yields. This study aims to characterize vegetable farming practices in Brazzaville and to determine their influence on soil properties. In the selected sites, structured questionnaire was conducted among market gardeners and soil samples were taken following transects. Soil physical and chemical analyses were carried out following lab common procedures. The results showed that the cultivation practices in the sites studied are intensive. The soils studied are more than 95% sandy, acidic, low in organic matter and have a relatively low CEC. However, there is an oversaturation in exchangeable bases on all sites. Thus, this oversaturation would be linked to the intensification of cultural practices.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.