Climate change, coupled with insufficient and irregular rains, led to a decline in the productivity of Ivorian cocoa production. The present study aimed to screen three cocoa (Theobroma cacao L.) genotypes in order to evaluate their response to water stress at callus and somatic embryos induction and proliferation stages. Staminode and petal explants of the genotypes C1, C14 and C16 from the collection of National Center of Agronomic Research (CNRA) of Ivory Coast, were placed on medium DKW (Driver & Kuniyuki Walnut) in the presence of different concentrations of Polyethylene glycol (PEG) 6000 (0, 25, 50, 75, 100 and 125 g/l). This polymer was used as osmoticum to stimulate water stress. Data were recorded for callus induction frequency, callus fresh weight, embryogenic callus percentage and average number of somatic embryos. The results obtained showed that intensity of callus proliferation decreased with increasing concentration of PEG 6000. In all genotypes tested, only the petal explants underwent somatic embryogenesis. The induction rates and average number of somatic embryos per explant were reduced with the increase in the concentration of PEG 6000. Among the tested genotypes, C1 produced somatic embryos with all concentrations of PEG 6000 and expressed highest frequencies of induction (62%) and average number of somatic embryos per explant (6.22). This genotype would be the most tolerant to water stress. Somatic embryos obtained with high concentrations of PEG 6000 in this study provide an important basis for the selection and further production of water stress-tolerant varieties of cocoa.

Côte d'Ivoire is the world's leading producer and exporter of cashew nuts. However, walnut yields in Ivorian orchards remain low. These low yields are due to a park of aging orchards, lack of improved varieties and high density of plantations. The general objective of this study is to contribute to the renewal of the cashew apple orchard by the technique of over grafting To achieve this, trees of different ages and low productivity were received at different heights, different trunk circumferences and under different levels of thinning. Three months after the grafting, grafts taken from elite trees were grafted on the regrowth. The results collected showed that the youngest trees and older trees gave the shortest regrowth (30.52 to 33.38 days). The number 307 of leafy shoots, the leaf area of the leaves emitted and the percentage of success were greater when the trees were retrieved at a height of 140 cm from the ground. . The analysis of variance made it possible to highlight the difference between the individuals for each factor studied. Trees larger than 50 cm produced the largest number of leafy shoots (32). Depending on the level of thinning, the well-lit gryphon was more vigorous. The average weights of the trees grafted according to the genotypes were between 27.5 and 234 g / tree against 493 g / tree for non-grafted plantation trees.

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