Allelopathic effects of aqueous extract of liquorice (Glycyrrhiza glabra L.) on seed germination and seedling growth of wheat and some weed species

Kawa Faisal Mustafa1 , Muhammed Najeeb Khasraw, Nawroz Abdul-razzak Tahir2, Shangeen Hama Salih Nadir, Hikmat Noori Mahmood 

Field Crops Department, Faculty of Agricultural Sciences, University of Sulaimani, Sulaimani, Iraq


A laboratory experiment using completely randomized design with three replicates was conducted in April 2015, to evaluate the germination and seedling growth of three plant types; Wheat (Triticum aestivum L.), Wild oat (Avena fauta L.) and Milk thistle (Silybum marianum L.) seeds were soaked in distilled water (control), 30 and 50% of liquorice (Glycyrrhiza glabra L.) leaf and root aqueous extracts to study the allelopathic potential effects of them. Whereas liquorice leaf and root aqueous extracts concentrations increased from 30 to 50%, the inhibitory effect of allelopathic materials on germination, growth, and seed vigour index, fresh and dry weight of seedling also increased. The results showed that S. marianum was the most sensitive to liquorice leaf and root extracts than A. fauta., although both were most sensitive to leaf and root extract. Wheat seeds were the most resistant to liquorice leaf and root extracts than both weed seeds. Leaf and root aqueous extracts showed non-significant different between them for all studied traits. The strong negative relationship was observed among extract concentrations and studied parameters.

 Key Words: Allelopathy, Liquorice, germination, weed aqueous extract and wheat.


[1] Asghari-Pour, M.R., Rashed-Mohassel, M.H., Rostami, and Elizadi, E.The allelopathic potential of Saffron (Crocus sativus L.) on following crop in rotation: IInd international symposium on Saffron biology and technology, Mashhad, Iran, pp. 28-30.( 2006 ).

[2] Magdalena-Stefan, T.Y.R., Lacko, B. and Pavol, O. "Weed infestation of winter wheat in integrated and ecological arable farming system". Acta Fyto Zoot, Vol.(4), pp. 20-21.( 2001).

[3]Khan, A.L., Gilani, S.A., Fujii, Y. and Watanabe, K.N. “Monograph on Inula britannica L. Mimatsu Corporation”, Tokyo-Japan. ISBN 978-4- 903242-24-8.( 2008).

[4] Zimdahl, R.L. “Fundamentals of Weed Science”. 3rd ed. Academic Press, an imprint of Elsevier. p. 688. (2007).

[5] Foy, C.L. and Inderjit. "Understanding the role of allelopathy in weed interference and declining plant diversity". Weed Technology, Vol.(15), pp. 873–878.( 2001 ).

[6]  Inderjit, Kaur M. and Foy, C.L. "On the significance of field studies in allelopathy", Weed Technology, Vol.(15), pp. 792–797. (2001).

[7]Norsworthy, J. K. "Allelopathic potential of wild radish (Raphanus raphanistrum) ", Weed Technology, Vol.(17), pp. 307–313. (2003).

[8] Duke, S.O., Dayan, F.E., Rimando, A.M., Schrader, K.K., Aliotta, G., Oliva, A. and Romagni, J.G. "Chemicals from nature for weed management", Weed Sciences, Vol.(50), pp.138–151. (2002)

[9] Jalali, M., Bahareh, P.M. and Khadrijeh, S. "Allelopathic effects of aqueous extract of shoot and root of licorice (Glycyrrhiza glabra L.) and pigweed (Amaranthus retroflexus L.) on germination characteristic and seedling growth of corn and chickpea", International Journal of Agriculture and Crop Sciences, Vol.(2), No.4, pp. 357-363. (2012).

[10] FAOSTAT. http://faostat.fao.org/site/567/DesktopDefault.aspx?PageID=567#ancor (2015).

[11]Malik, M.A., Faisal, Z., Muhammad, R.A., Muhammad, R., Umarah, A., Khalid, M. and Raza, A.H. "Weed biomass and economic yield of wheat (Triticum aestivum l.) as influenced by chemical weed control under rainfed conditions", African Journal of Biotechnology, Vol.(11), No.7, pp. 1567- 1573. ( 2012).

[12] Tahir, N.A. "Germination characteristics and molecular characterizations of some wheat varieties in Sulaimanyah by SSR marker", Turkish Journal of Biology, Vol.(34), pp.109-117. (2010).

[13] Abdul-Baki, A.A. and Anderson, J.D. "Vigor determination in soybean seed by multiple criteria", Crop Science, Vol.(13), pp. 630-633. (1973).

[14] Mubeen, K., Nadeem, K.M., Asif, T. and Zahir, A.Z.. "Allelopathic effect of aqueous extracts of weeds on the germination and seedling growth of rice (Oryza sativa L.) ", Pakistan Journal of Life and Social Sciences, Vol.(9), No.1, pp. 7-12.(2011).

[15] Putnam, A.R. and Duke, W.B. "Biological suppression of weeds: Evidence for allelopathy in accessions of cucumber", Science, Vol.(185), pp. 370–372. (1974).

[16] Bora, I.P., Singh, J., Borthakur, R. and Bora, E. "Allelopathic effect of leaf extracts of Acacia auriculiformis on seed germination of some agricultural crops", Annals of Forest science, Vol.(7), pp. 143-146. (2007)

[17] Fagg, C. and Stewart, J.L. "The value of Acacia and prosopis in arid and semi-arid environments", Journal of Arid Environments, Vol. (27), pp. 3-25. (1994)

[18]Katoch, R., Anita, S. and Neelam, T. "Allelopathic influence of dominant weeds of North – Western himalayn region on common cereal crops", International Journal of Environment Sciences, Vol.(3), No.1, pp. 84-97. (2012).

[19] Ankita, G. and Mittal, C. "Effect of alleopathic leaf extract of some selected weed flora of Ajmer district on seed germination of Triticum aestivum L", Journal of Scientific Research and Report, Vol.(3), No.2, pp. 311-315. (2012).

[20] Navaey, H., Najafi, H., Gholami, T., Ghaderi, F.M. and Sanei, M. "Allelopathic effect of water extract of Liquorice (Glycyrrhiza glabra) on germination and chlorophyll content of Maize", Journal of Novel Applied Sciences, Vol.(2), No. S 4, pp. 1220-1223. (2013).

[21]  Ghafarbi, S.P., Sirous, H. and Ramin, L. "Allelopathic effects of wheat seed extracts on seed and seedling growth of eight selected weed species", International Journal of Agriculture and Crop Sciences, Vol.(4), No.19, pp.1452-1457. (2012).

[22] Turk, M.A., and Tawaha, A.M. "Inhibitory effects of aqueous extracts of black mustard on germination and growth of lentil", Pakistan Journal of Agronomy, Vol.(1), pp. 28-30. (2002).

[23]Mlakar, S.G., Jakop,. M, Bavec, M. and Bavec. F. "Allelopathic effects of Amaranthus retroflexus and Amaranthus cruentus extracts on germination of garden cress", African Journal of Agricultural Research, Vol.(7), pp. 1492-1497. (2012).