No abstract

Malgré son importance socioéconomique, la production ivoirienne de noix de cola est confrontée à plusieurs difficultés. Le manque de techniques culturales éprouvées constitue une des contraintes pour la domestication et la culture du colatier. Il est donc nécessaire de mettre au point des techniques adaptées à l’espèce cultivée. L’objectif de cette étude est d’optimiser la méthode de bouturage sous tunnel du colatier (Cola nitida), face aux inconvénients de la multiplication générative. Le dispositif expérimental utilisé est un Split-Splot avec deux facteurs : le génotype avec cinq modalités (5 génotypes) et le nombre de feuilles avec cinq (05) modalités (1, 2, 3, 4 et 5 feuilles diminuées de moitié). Nous avons le génotype en grande parcelle et le nombre de feuilles en petite parcelle. L’aptitude des génotypes au bouturage a été évaluée à six mois à travers le taux de survie et la mesure des paramètres de croissance et de développement. Le génotype L18A1D9 a montré la meilleure aptitude au bouturage avec un taux de survie de 41,7%. Les boutures avec 4 feuilles diminuées de moitié ont eu le meilleur taux de survie (41,7%), un bon enracinement des boutures vivantes (88,9%), une biomasse totale fraîche (4,2 g) et totale sèche (1,7 g) élevée. Le succès du bouturage sous tunnel du colatier est tributaire du génotype et du nombre de feuilles. Le nombre de feuilles recommandé par bouture est de quatre (4) pour le bouturage du colatier sous tunnel.Mot clés : Bouturage, nombre de feuilles, Cola nitida, génotype. Englsih Title: Influence of genotype and number of leaves on the growth in nurseries of cola cuttings (Cola nitida [Wind.] Schott and Endlicher.)Despite its socio-economic importance, kola nut production faces several challenges. Domestication and cultivation of kola requires the adoption of propagation techniques adapted to the crop species. The objective of this study is to optimize kola (Cola nitida) vegetative propagation by cutting under tunnel. The experimental design used was a split-splot with two factors: genotype with five modalities (5 genotypes,) and leave number with five (05) modalities (1, 2, 3, 4 and 5 leaves cut in half). The ability of genotype to cutting propagation was assessed by measuring growth parameters. The survival rate of the cuttings was evaluated at six months. Root growth, number of new leaves, height gain and biomass were subsequently measured. Genotype L18A1D9 has the best ability for  vegetative propagation by cuttings with a survival rate of 41.7%. To optimize vegetative propagation by cuttings under tunnel, 4 leaves cut in half by cuttings must be used for acceptable success rate (41.7%), good rooting (88.9%), a high total fresh biomass (4.2 g) and total biomass (1.7g). The success of kola vegetative propagation depends of genotype and the leave number per cutting. The number of leaves per cuttings  recommended per cuttings is four (4) for kola vegetative propagation.Keywords: Cuttings, number of leaves, Cola nitida, genotype.

The rice/cassava rotation is one of the dominant rice-based cropping systems in western Côte d'Ivoire due to the inaccessibility of chemical fertilisers. The low productivity of this cropping system makes it necessary to think about improving agronomic performance. The objective of this study is to determine the effect of the rice/cassava rotation on the agronomic parameters of these crops. To achieve this objective, an agronomic trial was set up at the CNRA Research Station in Man on a Ferralsol. Five cropping sequences were compared in a Fischer block design with 5 treatments and 4 replications: 2 intensive monocultures of rice (0.20 m × 0.20 m) and cassava (1 m × 1 m) and 3 alternations of rice and cassava (R/M/R, M/R/M and R/R/M (farmer control)). The parameters measured were height, tillering, and yield of rice and cassava, as well as soil chemical parameters. The results showed that rice in rotation with cassava had a significant effect on cassava production, while cassava had no significant effect on rice grain yield. The rice-cassava rotation harmed soil chemical parameters. Except for the improvement of nitrogen and phosphorus contents due to biochemical reactions in the rhizosphere and the mobility of nutrients along the fertility gradient. Finally, R/M/R was found to be the best cropping sequence in a rice-based cropping system.

In Côte d'Ivoire, rubber cultivation is experiencing spectacular development. With land saturation in its traditional growing zones, rubber trees increasingly occupies new regions, including the west of the country. The objective of this study is to assess the place of rubber trees in the dynamics of production systems in the semi-mountainous region of western Côte d'Ivoire.This study was carried out through a survey carried out among nearly 402 rubber planters from the Tonkpi region and part of the Guemon region. A semi-open questionnaire was used to collect data, particularly those relating to the profile of the farmer and the relationships that prevail between rubber trees and other crops.Data analyzes have shown that the total area of production systems is 2758.12 ha, or 6.86 ha per farmer, and that of rubber trees is 1268.69 ha, or 2.41 ha per farmer. The average age of rubber fields is 8 years in 2019. Rubber plots were established between 1990 and 2019, of which 84 pc between 2007 and 2015. Planters use perennial polyculture in 76.87 pc of cases. Rubber cultivation occupies 46 p.c. of cultivated areas with coffee (45.63 p.c.) as the dominant previous crop. The rubber tree is grown in combination in 67.87 p.c. of cultural situations. Food crops are mostly (86.83 p.c.) used in associations.Rubber cultivation occupies half of the production system in western Côte d'Ivoire and the relations which prevail between rubber trees and the other components of this system are, on the one part, relations of substitution of rubber for perennial cultures (Coffee) and on the other part relations of association with food crops.