Allelopathic effects of blue gum (Eucalyptus globules), sweet basil (Ocimum basilicum), wormwood (Artemisia annua) and sweet potato (Ipomoea batatas) extracts on seeds germination and seedling development of some weed species.

Abstract: Laboratory experiments were conducted during the period from 2005 to 2007 to study the allelopathic potential of some aqueous methanol extracts of blue gum (Eucalyptus globules), sweet basil (Ocimum basilicum), sweet potato (Ipomoea batatas) and wormwood (Artemisia annua) on seed germination and seedling growth of wild oat (Avena sp.), canary grass (Phalaris sp.), dentated duck (Rumex dentated duck) and redroot pigweed (Amaranthus retroflexus L). Aqueous methanol 50% soluble extracts of these crop species were used to study their inhibitory effects to all studied common weeds such as wild oat, canary grass, dentated duck and redroot pigweed at extract concentrations of blue gum concentrations were 0, 12, 14, 16, 18, 20 and 22 mg/ml-1c, sweet basil and wormwood concentrations were 0, 10, 12, 14, 16, 18 and 20 mg/ml-1c, while the extract concentration of sweet potato were 0, 48, 64, 80, 96, 112 and 128 mg/ml-1c .
Results showed that all studied extracts inhibited the germination and seedling growth of weed species under study. Inhibition was more pronounced on roots than shoots. of weed species seedlings. The maximum inhibition was 96.7, 93.5 and 82.5% for canary grass obtained by 20 mg/ml-1 sweet basil, 128 mg/ml-1c sweet potato and 22 mg/ml-1c blue gum concentrations, respectively.
Weed species sensitivity estimated by the required extract concentration to cause 50% inhibition of seed germination (I50) show that small size seeds as redroot pigweed, dentated duck were more sensitive than big size seeds as wild oat and canary grass . The I50 estimates for blue gum extract was 16.6, 14.7, 13.1 and 11.5 mg/ml-1c and sweet basil extract was 11.4, 13.9, 14.5 and 12.0 mg/ml-1c for wild oat, canary grass, redroot pigweed and dentated duck, respectively. I50 for sweet potato extract was 91, 84 and 50 mg fresh weight of stored root/ml-1c for canary grass, dentated duck and redroot pigweed. Wormwood extract I50 was estimated by 15.36 mg dry weight/ml-1c for redroot pigweed.
This study suggest that some crop species extract are promising to be used as biological agent for suppressing weeds in crop fields through including these crops with allelopathic potential in crop rotation or coverage crop as well as the need of conducting further field studies for the determination of allelopathy in other plant species.
bI50 estimates were calculated using mg plant tissue extracted per ml of water used for seed germination as concentration (mg /ml-1b).
cI50 estimates were calculated using dry weight of extractable material per ml of water used for seed germination as concentration (mg /ml-1c).
Publication year 2008
Pages 95-106
Organization Name
serial title Egypt. J. of Appl. Sci.
ISSN 1110-1571
Author(s) from ARC
Agris Categories Protection of plants - General aspects
AGROVOC
TERMS		 Artemisia annua. Eucalyptus globulus. Ipomoea batatas. Ocimum basilicum.
Proposed Agrovoc Allelopathic;Avena sp;Phalaris sp.;Rumex dentated;Amaranthus retroflexus;
Publication Type Journal
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