Journal of Chemical Ecology

, Volume 17, Issue 2, pp 343–352 | Cite as

Investigations on some aspects of chemical ecology of cogongrass,Imperata cylindrica (L.) Beauv.

  • Inderjit
  • K. M. M. Dakshini


To understand the interference mechanism of the weed, cogongrass,Imperata cylindrica (L.) Beauv., its effect on nutrient availability and mycoflora of its soil rhizosphere as well as nodule characteristics, root length, and root/shoot ratio of Melilotus parviflora Desf. were investigated. Additionally, the effect of the leachates of leaves and root/rhizome of cogongrass on seed germination and seedling characteristics of radish, mustard, fenugreek, and tomato were examined. Furthermore, to assess the qualitative and quantitative differences in phytochemical components, the leachates and the soils from three sampling sites (with cogongrass and 1.5 m and 3 m away from cogongrass) were analyzed with high-performance liquid chromatography (HPLC) on a C18 column. No significant difference in nutrient availability was found, but qualitative and quantitative differences in phenolic fractions were recorded in the three sampling sites. Furthermore, of the 19 fungi recorded in the soils, decreases in the number of colonies (per gram of soil) ofAspergillus fumigatus, A. niger, A. candidus, and an increase of A. flavus was recorded in the soils with cogongrass. The inhibition in nodule number, weight, nitrogen fixation (acetylene reduction activity), root length, and root/shoot ratio of Melilotus parviflora were noted. Percent seed germination, root and shoot length, fresh and dry weight of seedlings of different seeds were affected by the leachates of leaves and root/rhizome. It was found that root/rhizome leachate was more inhibitory than leaf leachate. However, the inhibition was higher in soil+leaves leachate than soil+root/rhizome leachate. HPLC analysis established that four compounds were contributed by the weed to the soil system even though their relative concentration varies in various leachates. It is surmised that these compounds cause allelopathic inhibition of growth characteristics of seeds tested. Significance of the data vis-a-vis the interference potential of the cogongrass is discussed.

Key Words

Allelopathy cogongrass competition Imperata cylindrica HPLC interference weed 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Abdul-Wahab, A.S., andAl-Naib, F.A.G. 1972. Inhibitional effects ofImperata cylindrica (L.)P. B. Bull. Iraq Nat. Hist. Mus. 5:17–24.Google Scholar
  2. Allen, S.E. (ed.). 1989. Chemical Analysis of Ecological Materials. 2nd ed. Blackwell Scientific, Oxford.Google Scholar
  3. Dickinson, C.H. 1971. Cultural studies of leaf saprophytes, pp. 293–324,In C.H. Dickinson and T.F. Preece (eds.). Ecology of Leaf Surface Micro-organisms. Academic Press, London.Google Scholar
  4. Einhellig, F.A., andKuan, L.A. 1971. Effect of scopoletin and chlorogenic acid on stomatal aperture in tobacco and sunflower.Bull. Torrey Bot. Club 98(3): 155–162.Google Scholar
  5. Glass, A.D.M. 1973. Influence of phenolic acids on ion-uptake: Inhibition of phosphate uptake.Plant Physiol. 51:1037–1041.Google Scholar
  6. Hartley, R.D., andBuchen, H. 1979. High performance liquid chromatography of phenolic acids and aldehydes derived from thedecomposition of organic matter in the soil.J. Chromatogr. 180:139–143.Google Scholar
  7. Holm, L. 1969. Weed problems in developing countries.Weed Sci. 17:113–118.Google Scholar
  8. Lodhi, M.A.K., andRice, E.L. 1971. Allelopathic effects ofCeltis laevigata.Bull. Torrey Bot Club 98:83–89.Google Scholar
  9. Mersie, W., andSingh, M. 1988. Effects of phenolic acids and ragweed Parthenium (Parthenium hysterophorus) extract on tomato (Lycopersicon esculentum) growth and nutrient and chlorophyll content.Weed Sci. 25:278–281.Google Scholar
  10. Olsen, R.A., Odham, G., andLindeberg, G. 1971. Aromatic substances in leaves ofPopulus tremulaas inhibitors of mycorrhizal fungi.Physiol. Plant. 25:122–129.Google Scholar
  11. Rice, E.L. 1984. Allelopathy, 2nd ed. Academic Press, Orlando, Florida.Google Scholar
  12. Rose, S.L., Perry, D., Pilz, D. andSchoeneberger, M.M. 1983. Allelopathic effect of litter on growth and colonization of mycorrhizal fungi.J. Chem. Ecol. 9(8): 1153–1162.Google Scholar
  13. Williams, R.D., andHoagland, R.E. 1982. The effects of naturally occurring phenolic compounds on seed germination.Weed Sci. 30:206–212.Google Scholar

Copyright information

© Plenum Publishing Corporation 1991

Authors and Affiliations

  • Inderjit
    • 1
  • K. M. M. Dakshini
    • 1
  1. 1.Department of BotanyUniversity of DelhiDelhiIndia

Personalised recommendations