Floristic and ecological analysis of weeds in citrus groves in the oranian phytogeographic sector (Western Algeria)

The weeds in agro ecosystem are known as a critical problem which is associated with severe economic loss. There is a lacking in the information about biology and ecology of weeds communities in agro ecosystems of the north-western tell of Oranie (western Algeria), particularly citrus farms. The study of citrus weeds in this region during the 2015-2016 crop years included 200 phytoecological surveys according to the round-field sampling method. They were distributed in five sites the study area in order to take into account the variability of ecological and Agronomic factors. The flora recorded at all the sites includes 101 weed species belonging to 31 families and 87 genera. The dominant families were Asteraceae. Poaceae and Fabaceae this weeds flora was dominated by the Mediterranean elements (43%) and the therophytes (74.5%) reflecting unfavourable climatic conditions. The results obtained by Principal ComponentAnalysis shows the existence of three distinct groups of study sites for both weed families and biological types. Correspondence Factor Analysis revealed two groups of species with different correlations to the study sites and the ecological parameters considered these results explain the distribution of citrus weeds in Oranian region according to climate edaphic conditions.