Allelopathic effects ofCitrus aurantium L.
Field observations on undisturbed stands of sour orange revealed thatCynodon dactylon, Chenopodium album, Avena sativa, andAmaranthus retroflexus were not able to grow normally and complete their life cycles under its canopies, although the same species grow well under adjacent trees of date palm. Investigations revealed that the failure of the test species to grow normally under sour orange was not due to competition for light, moisture and minerals or to differences in soil texture or pH. Soil under sour orange trees drastically reduced seed germination and/or seedling growth of test species. Aqueous extracts, decaying materials, and volatile compounds of senescent and nonsenescent sour orange leaves were found to inhibit seed germination and/or seedling growth of test species. Therefore, allelopathy appeared to be the basic factor responsible for the reduction in plant growth with competition propably accentuating its effects.
Key wordsAllelopathy patterning sour orange Citrus aurantium date palm Phoenix dactylifera Cynodon Chenopodium Amaranthus Avena
Unable to display preview. Download preview PDF.
- Al-Naib, F.A., andRice, E.L. 1971. Allelopathic effects ofPlatanus occidentalis.Bull. Torrey Bot. Club 98:75–82.Google Scholar
- Anderson, J.V., andHarris, W. 1967. Determination of organic carbonates in soil.Soil Sci. Am. Proc. 31:341–343.Google Scholar
- Bouyoucos, G. 1936. Directions for making mechanical analysis of soils by hydrometer method.Soil Sci. 41:255–229.Google Scholar
- Bremner, J.M. 1965. Total nitrogen, pp. 1149–1178,in Methods of Soil Analysis, Part 2. C.A. Black ed. American Society for Agronomy, Inc., Madison, Wisconsin.Google Scholar
- Del-Moral, R., andGates, R.G. 1971. Allelopathic potential of dominant vegetation of western Washington.Ecology 52:1030–1037.Google Scholar
- Del-Moral, R., andMuller, C.H. 1970. The allelopathic effects ofEucalyptus camaldulensis.Am. Midl. Nat. 83:254–282.Google Scholar
- Grove, C.R., andAnderson, J.F. 1981. Allelopathic effects ofArtemisia tridentata leaves on germination and growth of two grass species.Am. Midl. Nat. 106:73–79.Google Scholar
- Hoagland, D.R., andArnon, D.I. 1950. The water culture method for growing plants without soil.Calif. Agric. Exp. Stn. Cir. 347.Google Scholar
- Horsley, S.B. 1977. Allelopathic interference among plants. II. Physiological modes of action, pp. 93–136,in H.E. Wilcox andA.F. Hamer (eds.). Proceedings of the Fourth North American Forest Biology Workshop. School of Continuing Education. College of Environmental Science and Forestry, Syracuse, New York.Google Scholar
- Lodhi, M.A.K. 1975. Allelopathic effects of hackberry in a bottomland forest community.J. Chem. Ecol. 1:171–182.Google Scholar
- Olsen, S.R.,Colec, V.,Watanabe, F.S., andDean, L.A., 1954. Estimation of available p in soils by extraction with sodium bicarbonate.U.S. Dept. Agric. Cir. 939.Google Scholar
- Piper, C.S. 1942. Soil and Plant Analysis. University of Adelaide, Adelaide, Australia, 368 pp.Google Scholar
- Rice, E.L. 1972. Allelopathic effects ofAndropogon virginicus and its persistence in old fields.Am. J. Bot. 59:752–755.Google Scholar
- Rice, E.L. 1974. Allelopathy. Academic Press, New York.Google Scholar
- Rice, E.L. 1979. Allelopathy. An update.Bot. Rev. 45:15–109.Google Scholar