Allelopathic Potential of Aerial and Root Extracts of Alfalfa Against Germination and Seedling Related Traits of Four Weed Species.

Abdulsalam Abdulrahman Rasool
Field Crops Department, Faculty of Agricultural Sciences, University of Sulaimani


In this study, we investigated the effect of aerial and root water extract of Alfalfa
(Medicago sativa) plant on seed germination and seedling growth of four weed species. This
study was carried out in the phytochemistry laboratory/Faculty of Agricultural Sciences/Sulaimani
University. Factorial experiment conducted in Completely Randomized Design (CRD) with 3
replications, including five concentrations 2,4,6,8 and 10 g of aerial and root dry tissues of alfalfa
(Medicago sativa L.) plants per 100ml of MeOH 70% v/v, against germination and seedling growth
of four problematic weeds, which widely distributed in wheat fields, namely cephalaria (Cephalaria
syriaca L.), rye grass (Lolium perenne L.), bitter vetch (Lathyrus linifolius L.) and black mustard
(Brassica nigra L.). Results of experiment showed that extracts from dry tissue of aerial and root
parts of alfalfa greatly inhibited seed germination and seedling growth of weeds at all
concentrations compared to water control. Root extracts had the higher allelopathic potential
toward imbibitions and germination of weeds compared to aerial extracts. Root extract reduced
imbibitions by 61, 54, 61, 54 % and caused germination inhibition I%, by 51, 37, 34, and 47 % in
cephalaria, rye grass, bitter vetch and black mustard respectively. Aerial extracts, significantly
reduced hypocotyls, radicle length and dry weight compared to root extracts. The reduction of
seedling traits of cephalaria, rye grass, bitter vetch and black mustard respectively due to aerial
extracts compared to water control were 52, 52, 32, 35% hypocotyls length reduction, 41, 44, 33,
48% radicle length reduced, 58, 61, 64, 76% hypocotyls dry weight losses and 60, 57, 58, 77% were
losses in radicle dry weight. Allelopathicity increased for aerial and root tissues with increase in
concentrations and the greatest inhibition was 80% equally for imbibitions and I%, which obtained
by 10g dry root tissue per 100 ml MeOH extract occurred in cephalaria, while 10 g dry aerial tissues
per 100 ml MeOH extracts shows the highest inhibition percentages of hypocotyls length by 78% in
rye grass, radicle length by 79% in cephalaria, hypocotyls dry weight and radicle dry weight by
90% both in black mustard.

Keywords: Allelopathy, Medicinal plants, Saponins, Phenolic compounds, Bio-herbicides,
problematic weeds.


[1] Torres, A., R. M. Oliva, D. Castellano and P. Cross. First World Congress on Allelopathy.
A Science of the future, S.A.I., University of Cadiz, Spain, 1996.
[2] Fujii, Y., S. S. Parvez, M. M. Parvez, y. Ohmae and Y. Iida. Screening of 239 medicinal
plant species for allelopathic activity using the sandwich method. Weed Biol. Manage, 3;
233-241, 2003.
[3] Lin, D., E. Tsuzuki, Y. Dong, M. Matsuo and H. Terao. Assessment of dwarf Lilyturf
(Ophiopogon japonicus K.) dried powders for weed control in transplanted rice. Crop
Prot., 22; 431-435, 2003.
[4] Lin, D., E. Tsuzuki, Y. Dong, M. Matsuo and H. Terao. Elementary identification and
biological activities of phenolic allelochemicals from dwarf Lilyturf (Ophiopogon
japonicus K.) against two weeds of paddy rice field. Plant Prod. Sci., 7 (3); 260-265, 2004.
[5] Han, C. M., K. W. Pan, N. Wu, J. C. Wang and W. Li. Allelopathic effect of ginger on seed
germination and seedling growth of soybean and chive. Sci. Hor., 116 (3); 330-336, 2008.
[6] Sodaeizadeh, H., M. Rafieiolhossaini, J. Havlik and P. Van Damme. Allelopathic activity
of different plant parts of Peganum harmala L. and identification of their growth inhibitors
substances. Plant Growth Regul., 59; 227-236, 2009.
[7] Li, H., K.W. Pan, Q. Liu and J. C. Wang. Effect of enhanced ultraviolet-B on allelopathic
potential of (Zanthoxylum bungeanum). Sci. Hor., 119 (3); 310-314, 2009.
[8] Mominul Islam, A. K. M. and K-N. Hisashi. Plantgrowth inhibitory activity of medicinal
plants (Hiptis suaveolens) :could allelopathy be a cause? Emir. J. Food Agric., 25 (9); 692-
701, 2013.
[9] Singh, H. P., R. Batish, R. K. Kohli. Hand Book of Sustainable Weed Management. Food
Products Press, 2006.
[10] Zahid, H., F. Munsif, S. I. A. Shah, B. Gul, N. Khan, S. D. Kakar and A. Ahmad.
Assessment of weed problems in wheat crop of Peshawar Pakistan. Pak. J. Weed Sci. Res.,
18 (3); 357-366, 2012.
[11] Wilson, C. and C. Tisdell. Why farmers continue to use pesticide despite environmental,
health and sustainability costs? Ecol. Econ., 39; 449-462, 2001.
[12] Ellen, De. G., L. Ellen, G. Danny and S. Guy. Novel advances with plant saponins as
natural insecticides to control pest insects. Pest tech., 1 (2); 96-105, 2007.
[13] Oleszek, W., J. M. Gee, G. M. Wortley and I. T. Johnson. Effects of some purified alfalfa
(Medicago sativa L.) saponins on transmural potential difference in mammalian small
intestine. J. Sci. Food Agric., 65; 35-39, 1994.
[14] Goriski, P. M., J. Miersch and M. Ploszynski. Production and biological activity of
saponins and conavanine in alfalfa seedling. J. Chem. Ecol., 17; 1135-1143, 1991.
[15] Xuan, T. D. and E. Tsuzuski. Varietal differences in allelopathic potential of alfalfa. J.
Agron. Crop Sci., 188 (1); 2-7, 2002.
[16] Chung, Ill-M., D. Seigler, D. A. Miller and S-H. Kyung. Autotoxic compounds from fresh
alfalfa leaf extracts: identefication and biological activity. J. Chem. Ecol., 26 (1); 315-327,
[17] Chon, S. U. and J. D. Kim. Biological activity and quantification of suspected
allelochemicals from alfalfa plant parts. J. Agron. Crop Sci., 188 (4); 281-285, 2002.
[18] Ireland, P. A. Analysis of saponins. PhD. Thesis, Reading University, U. K., 1987.
[19] Bich, T. T. N. and H. Kato-Noguchi. Allelopathic potential of four emergent macrophytes
on the growth of terrestrial plant species. Int. J. Biosci. Biotech., 4 (4); 81-93, 2
[20] Massiot, G., C. Lavaud, V. Besson, L. L. Men-Oliver and G. V. Binst. Saponins from aerial
parts of alfalfa (Medicago sativa L.). J. Agric. Food Chem., 39; 78-82, 1991.
[21] Koloren, O. Allelopathic effects of Medicago sativa L. and Vicia cracca L. leaf and root
extracts on weeds. Pak. J. Biol. Sci., 10 (10); 1639-1642, 2007.
[22] Yarnia, M., E. Farajzadeh, V. Ahmadzadeh and N. Nabari. Allelopathic effect of corn,
alfalfa, red root pigweed and Bermuda grass on germination and growth of rye. Int. J.
Biosci., 3 (3); 41-49, 2013.
[23] Karaoglu, M. M. Cephalaria syriaca L. addition to wheat flour dough and effect on
rheological properties. Int. J. Food Sci. Tech., 41; 37-46, 2006.
[24] Siddiqui, I., R. Bajwa, Z. E. Huma and A. Javid. Effect of six problematic weeds on growth
and yield of wheat. Pak. J. Bot., 42 (4); 2461-2471, 2010.
[25] Hua, S., P. ShaoLin, W. XiaoYi, Z. DeQing, Z. Chi. Potential allelochemicals from an
invasive weed Mikania micrantha H.B.K. J. Chem. Ecol., 31;1657–1668, 2005.
[26] Steel, R. G. D., J. H. Torrie, and D. A. Dickey. Principles and procedures of statistics: A
biometrical approach. 3rd ed. McGraw Hill book Co. Inc. New York, pp: 400-428, 1997.