Production Fruitière De Quatre Essences Ligneuses Dans La Forêt De Nassou En Zone Soudanienne Du Bénin

Rural populations are closely dependent on plant resources for their daily needs. Fruit productivity of these species is an indicator of their economic potential and their capacity to regenerate. This is also fundamental to define sustainable management strategies of species. The present study assessed the fruits and seeds productivity of four forest species such as Vitex doniana, Afraegle paniculata, Diospyros mespiliformis and Kigelia africana according to the diameter class of trees. The study was carried out in the Nassou forest in soudanian zone of Benin. 09 to 90 trees belonging to four diameter classes (10-20 cm, 20-30 cm, 30-40 cm, and≥ 40 cm) were sampled for each species. The method used is the counting of fruits fallen under the tree through a periodic collection carried out every five days from the fructification to the end of the cycle and the fall of the last fruit. Seeds were then extracted from fruits. Generalized linear models of Poisson family were used to analyse data. Results revealed that the diameter class on the one hand influence significantly (Prob. ≤ 0.01) the production of fruits of K. africana and V. doniana, and on the other hand the production of seeds of A. paniculata, D. mespiliformis and V. doniana. Overall, fruits and seeds production is higher for the biggest tress (≥ 40 cm). Therefore, the diameter of the four studied species would be very useful for genetic improvement aiming the increasing of their productivity

Variabilité morphologiques et conservation des morphotypes de <i>Jatropha curcas</i> Linn. (Euphoriaceae) au Benin.

This study is a contribution to Jatropha curcas cultivation and seeks to analyze the morphological variability and identification of morphotypes of Jatropha curcas. The study was conducted in 44 communities equitably distributed among 22 towns (populations) and geographically widespread in the 10 phytodistricts of Benin. Per population, at least 30 individuals of the species spaced at least 20 meters apart were randomly selected for the collection of morphological data. In total, 840 individuals, 714 leaves, 2294 fruits and 3465 seeds of Jatropha curcas were measured in all the country. The part of the variability of Jatropha curcas morphological traits due to individual, populations, phytodistricts, climatic zones were determined using the variance component analysis. The stepwise discriminant analysis was performed on Jatropha curcas populations to identify the morphological traits which discriminate them and the numeric classification was realized to regroup Jatropha curcas populations. The results show that variability of Jatropha curcas morphological traits is generally larger at individual level or between individuals of the same population than between populations, phytodistricts and climatic zones except fruits and seeds weight whose variability is larger between populations. Ten of twenty-one morphological traits studied were identified as the most discriminant variables of Jatropha curcas. Four morphological groups of Jatropha curcas were distinguished in Benin considering 10 discriminant variables. Keywords: morphological traits, variability, Jatropha curcas, Benin