------ Raf. J. Sci., Vol. 24, No.2 pp. 1-10, 2013------ 1 The Effect of Aqueous Leaves Extracts of Eucalyptus camaldulensis on Germination and Growth of Three Weed Species Janan A. Saeed Eman R. Al-Rawi Fatin K. Ibraheem Department of Biology College of Science University of Mosul (Received 24/ 9 / 2012 ; Accepted 26 / 11 / 2012 ) ABSTRACT This research included experiments in laboratory and green house to study the effect of Eucalyptus camaladulensis leaf extracts at concentrations ( 5,10 and 15) % W:V on seed germination and growth of the weeds (Datura spp., Sonchus spp. and Sinapis spp.). Laboratory experiment, showed an inhibition in germination and seedling growth as the aqueous extracts concentration increased. The maximum inhibition in (germination, plumule length and weight) reaching (30.51, 52.4,56.2)% respectively in Sinapis, while the maximum inhibition in radical growth (55.5,53.5)% was shown in Datura at (15%). Green house results also showed that the highest inhibition (26.96,58.66,45.6)% respectively in germination and (shoot length and weight)in Sinapis at (15%), and high inhibition in (root length and weight) was (56.97,75.7)% in Datura at (15%). The Results were accompanied with the inhibition in the content of N, P, K maximum inhibition of N content (58.73%) in Datura, of P content (75.47%) in Sinapis and of K content (49.93%) in Datura at (15%). The content of the K increases in Sonchus at (10,15)% and in Sinapis at (15%). It was also shown that the weeds differ in their response to the allelopathic effect of Eucalyptus leaves extracts,indicating that Sinapis weed was sensitive whereas Sonchus seems to be resistant. Keywords: Allelopathy, Eucalyptus camaldulensis, Weeds. ــــــــــــــــــــــــــــــــــــــــــــــــــــ ﺍﻟﻤ ﺍﻟﻤﺴﺘﺨﻠﺼﺎﺕ ﺘﺄﺜﻴﺭ ﺍﻟﻴﻭﻜﺎﻟﺒﺘﻭﺱ ﻷﻭﺭﺍﻕ ﺎﺌﻴﺔEucalyptus camaldulensis ﺃﻨﺒﺎﺕ ﻓﻲ ﺍﻷﺩﻏﺎل ﻤﻥ ﺃﻨﻭﺍﻉ ﻟﺜﻼﺜﺔ ﻭﺍﻟﻨﻤﻭ ﺍﻟﺒﺫﻭﺭ ﺍﻟ ﻤﻠ ﺨﺹ ﺍﻟﻤـﺎﺌﻲ ﺍﻟﻤـﺴﺘﺨﻠﺹ ﺍﻀﺎﻓﺔ ﺘﺄﺜﻴﺭ ﻟﺩﺭﺍﺴﺔ ﺍﻟﺯﺠﺎﺠﻲ ﻭﺍﻟﺒﻴﺕ ﺍﻟﻤﺨﺘﺒﺭ ﻓﻲ ﺘﺠﺎﺭﺏ ﺍﺠﺭﺍﺀ ﺍﻟﺒﺤﺙ ﺘﻀﻤﻥ ﻷﻭﺭﺍﻕ ﺍﻟﻴﻭﻜﺎﻟﺒﺘﻭﺱ ﺒﺘﺭﺍﻜﻴﺯ,5) 15,10 ( % ﻭﺯﻥ: ﻓﻲ ﺤﺠﻡ ﺇﻨﺒﺎﺕ ﺍﻟ ﺍﻷﺩﻏـﺎل ﻤـﻥ ﺍﻨﻭﺍﻉ ﻟﺜﻼﺜﺔ ﻭﺍﻟﻨﻤﻭ ﺒﺫﻭﺭ ) Datura,Sonchus and Sinapis ( ﺍﻟﻤﻘﻁﺭ ﺍﻟﻤﺎﺀ ﻤﻊ ﻤﻘﺎﺭﻨﺔ. ﺍﻟﺜﻼﺜـﺔ ﻟﻸﺩﻏـﺎل ﻭﺍﻟﻨﻤﻭ ﺍﻻﻨﺒﺎﺕ ﻓﻲ ﺘﺜﺒﻴﻁ ﺤﺼﻭل ﺍﻟﻤﺨﺘﺒﺭﻴﺔ ﺍﻟﺘﺠﺭﺒﺔ ﻨﺘﺎﺌﺞ ﺃﻅﻬﺭﺕ ﺒﺎﺯﺩﻴـﺎﺩ ﺘﺭﻜﻴـﺯ ﻓﻲ ﻨﺴﺒﺔ ﺃﻋﻠﻰ ﻜﺎﻨﺕ ﺤﻴﺙ ﺍﻟﻤﺎﺌﻲ ﺍﻟﻤﺴﺘﺨﻠﺹ ﺍﻹﻨﺒﺎﺕ، ﺍﻟﺭﻭ ﻁﻭل ﻴ ﺍﻟﺠﺎﻑ ﻭﻭﺯﻨﻬﺎ ﺸﺔ) 56.2,52.4,30.51 %(