Effect of brown seaweeds and pesticides on root rotting fungi and root-knot nematode infecting tomato roots


  • V. Sultana
  • S. Ehteshamul-Haque
  • J. Ara
  • M. Athar


Plants with therapeutic effects have received attention of scientists as an alternate method of disease control which protect the environment from the use of hazardous chemicals. Experiments were conducted in the greenhouse to determine the effect of brown seaweeds Spatoglossum asperum and Sargassum swartzii on pathogenic fungi and parasitic nematode infecting tomato roots. Application of brown seaweeds as soil amendment showed a significant (p<0.05) suppressive effect on root rotting fungi Macrophomina phaseolina, Rhizoctonia solani and Fusarium solani and root-knot nematode, Meloidogyne javanica in tomato roots. Use of Sargassum swartzii with benomyl and Spatoglossum asperum with captan showed a better control of F. solani than each used individually. Combined use of Sargassum swartzii with benomyl and captan and Spatoglossum asperum with benomyl also greatly (p<0.05) reduced nematode infection than seaweeds or fungicides used individually. Maximum fresh shoot weight and plant height was obtained by the mixed application of seaweed and benomyl. The utilization of these seaweeds as manure may provide necessary nutrients to tomato plants and may protect them from invasion by root pathogens.