Prediction and evaluation of allelopathic plants species in Algerian Saharan ecosystem

Allelochemicals involved in plant-plant interaction (Allelopathy) are a potential source for alternative agrochemicals to solve the negative effects caused by synthetic herbicides. The present study is focused on the prediction and evaluation of allelopathic plants species in Saharan ecosystem from the Souf region in the southeastern of Algeria. The study was articulated through three steps of investigation: (1) a floristic survey, including a general inventory with notation of abundance and sociability scores for each species to understand the floristic composition of the study area, (2) Species co-occurrence analysis, using a presence/absence of data species in restricted sampling plots, which allowed to identify eight negatively associated species pairs with only one positive association and (3) allelopathic bioassays were performed with the aqueous extracts of the three species negatively associated species. The results showed a significant effect of aqueous extracts of Halocnemum strobilaceum (Pall.) M. Bieb, Retama raetam Forssk. Webb and Limoniastrum guyonianum Boiss on seed germination or seedling growth of target species (Lactuca sativa L., Daucus carota L., Triticum durum Desf. and Zea mays L.) at concentrations of 10 % and 15 %. H.strobilaceum showed the highest phytotoxic activity with 0% germination rate of all target species at concentration of 15 %, followed by R. raetam and L. guyonianum, and D. carota was the most sensitive target species with total inhibition of germination in most of treatments. Besides, plumule length was most affected then radicle length. It was conducted that some of these extracts may be represent a promising alternative bioherbicides from Saharan plants in agricultural and environmental management.