The Effect of Different Concentration of Glyphosate on the Growth of Coconut Seedlings

  • Senarathne, S.H.S. (Coconut Research Institute, Bandirippuwa Estate) ;
  • Jayaneththi, J.K.D.S.W. (Faculty of Agriculture, University of Peradeniya) ;
  • Premarathne, K.P.P. (Faculty of Agriculture, University of Peradeniya)
  • Received : 2012.08.13
  • Accepted : 2012.09.11
  • Published : 2012.09.30


Coconut (Cocos nucifera L) is one of the predominant plantation crops in Sri Lankan economy which is known to have existed for over thousands of years. During the past decades coconut production had been reduced by a significant quantity. The usage of poor quality planting materials is a major reason for the low coconut production. Thus much attention needs to be paid in coconut nurseries. Weed management is a critical management practice in the nursery. Though glyphosate application is becoming popular in nurseries it can affect weeds as well as coconut seedlings growth. Therefore the effects of glyphosate were evaluated by determining the growth of shoot and root of coconut seedlings. Poly bag nursery was prepared and three treatments were used. Treatments were no glyphosate and manual weeding ($T_1$), application of glyphosate 1.08 ai kg $ha^{-1}$ at 2 monthly interval ($T_2$) and application of glyphosate 1.44 ai kg $ha^{-1}$ at 2 monthly interval ($T_3$). Application of glyphosate at early stage of seedling growth had a no significant effect on growth parameters tested. However, the concentrations of glyphosate negatively affected numbers, volumes and dry weights of secondary, tertiary and quaternary roots at the latter stage of seedling growth. The leaf area and the height of seedling were significantly reduced by the highest concentration of glyphosate. Among the growth parameters tested, seedling girth and shoot dry weight were not affected by the application of glyphosate. These results revealed that the usage of glyphosate at both concentrations negatively affected root growth of coconut seedlings. Based on these results, the both concentration levels of glyphosate should be applied to coconut nurseries before sprouting the seed nuts.


  1. Bott, S., T. Tesfamariam, H. Candan, L. Cakma, V. Romheld, and G. Neumann. 2008. Glyphosate induced impairment of plant growth and micronutrient status in glyphosate-resistant soybean (Glycine max L.). Plant and Soil. 312:185-194.
  2. Boyall, L. A. 1998. The control of perennial weeds. In Recent Advance in Weed Research, (Eds:W.W. Fletcher). The Gresham Press. Surry. 141-166.
  3. Cole, D. J. 1985. Mode of action of glyphosate - a literature analysis. (In) The Herbicide Glyphosate. E. Grossbard and D.Atkinson (Eds). pp. 48-71. Butterworth and Co (publishers) Ltd. London. England.
  4. Coupland, D. and J.C. Caseley. 1979. New Phyto. 83:17-22.
  5. Curl, E. A. and B. Truelove. 1986. The Rhizosphere (Springer-Verlag, Berlin). 288p.
  6. Duke, S.O. 1988. In:Herbicides:Chemistry, Degradation, and Mode of Action (P. C. Kearney and D. D. Kaufman, eds., Marcel Dekker, New York). pp. 1-70.
  7. Ghosh, P., R. K. Ghosh, S. K. Ghosh, K. Barui, and A. Bhanja. 2007. Chemical weed control in non cropped areas. Proceedings of the 21stAsian Pacific Weed Science Society Conference (Editors:B. Marambe, U. R.Sangakkara, W. A. J. M. D. Costa and A. S. K. Abesekera). Colombo. Sri Lanka. pp. 109-111.
  8. Manipura, W. B. and, A. Somaratne. 1974. Some effects of manual and chemical defoliation on the growth and carbohydrate reserves of Panicum repens (L) Beauv. Weed Resarch. 14:167-172.
  9. Menon, K. P. V. and, K. M. Pandalai. 1958. The Coconut Palm; A Monograph. Indian Central Coconut Committee. South India.
  10. Pethiyagoda, U. 1980. Hand Book on Coconut Cultivation. Coconut Research Institute. Lunuwila. Sri Lanka.
  11. Senarathne, S. H. S. and K. C. P. Perera. 2005. Effects of different concentrations of glyphosate on control of weeds in coconut nurseries and growth of coconut seedlings in the dry zone of Sri Lanka. The Planter, Kuala Lumpur. 81:515-519.
  12. Senarathne, S. H. S. and K. C. P. Perera, 2009. Use of different herbicides on weed management in coconut nurseries in the intermediate zone of Sri Lanka. Korean J. of Weed Science 29:131-138.
  13. Toretensson, L. 1985. Behavior of glyphosate in soils and its degradation. In : The Herbicide Glyphosate. E. Grossbard and and D. Atkinson (Eds). pp. 137-151. Butterworth and Co (publishers) Ltd, London, England.