Trigonella foenum-graecum (fenugreek)-mediated suppression of Meloidogyne javanica in mungbean

Abstract

Soil amendments with powdered seeds of <i>Trigonella foenum - graecum</i> (fenugreek) caused soil suppressiveness against <i>Meloidogyne javanica</i>. Decomposed seeds of fenugreek caused marked reduction in nematode population densities and subsequent root-knot development as compared to the aqueous extract of the seeds indicating that some indirect factors are involved in the suppression of root-knot nematode. Both decomposed seeds and aqueous extracts enhanced plant height and fresh weights of shoot whereas root growth remained uninfluenced. Changes in fungal communities associated with nematode control were studied by comparing population numbers of fungi in the soil and in internal root tissues (endorhiza) in non-amended and fenugreekamended soils. <i>Acremonium</i> sp., <i>Chaetomium globosum, Fusarium solani, Macrophomina phaseolina</i> and <i>Rhizoctonia solani</i> were found to colonize inner root tissues of mungbean. <i>Acremonium</i> sp., <i>C. globosum</i> and <i>F.solani</i> were isolated in a relatively higher frequency from roots growing in the amended soils while <i>M. phaseolina</i> and <i>R. solani</i> colonized greatly in roots growing in non-amended soil. Of the fungi isolated from soils, <i>Penicillium brefaldianum</i> caused maximum juvenile mortality of <i>M.javanica</i> whereas <i>F.solani</i> caused greatest inhibition of egg hatch.