Effects of incorporation of allelopathic plants leaf residues on mycorrhizal colonization and Gladiolus diseases

In pot culture, the effects of leaf residue incorporation of five allelopathic plants (Azadirachta indica A. Juss., Ageratum conyzoides L., Calotropis procera Br., Parthenium hysterophorus L. and Momordica charantia L.) was studied on plant growth, incidence and severity of corm rot disease [by Fusarium oxysporum f.sp. gladioli (Massey) Snyd. & Hans], and root colonization by Arbuscular Mycorrhizal (AM) fungi in gladiolus (Gladiolus grandiflorus) cv Aarti. Inoculation of soil with F. oxysporum caused 100% disease incidence and 20% plant mortality. Soil incorporation of allelopathic plant leaf residues reduced the disease incidence by 6080% and increased the plant survival to 100%. F. oxysporum suppressed the shoot and root biomass of Gladiolus by 63 and 81%, respectively. This biotic stress was alleviated by incorporation of leaf residues of all allelopathic plant spp. Leaf residue incorporation drastically reduced (40–71%) the AM colonization.