Role of Zinc in Rhizobacteria‐Mediated Suppression of Root‐Infecting Fungi and Root‐Knot Nematode

• DOI: 10.1046/j.1439-0434.2002.00805.x
• Publication Date: 2003-03-12T08:29:21Z
• Authors: I. A. Siddiqui; S. S. Shaukat; M. Hamid
• Keywords: Meloidogyne javanica; Macrophomina phaseolina; Rhizoctonia

Abstract Understanding the environmental factors that influence rhizosphere and inner root colonization of disease‐suppressive strains fluorescent pseudomonads is an essential step towards improving level reliability their biocontrol activity. Soil amendment with Zn at 0.8 or 1.6 mg/kg soil alone in combination Pseudomonas aeruginosa IE‐6S + significantly reduced nematode penetration tomato roots. applied did not reduce infection caused by Macrophomina phaseolina Fusarium solani but when used . conjunction markedly suppressed Rhizoctonia infection. Plant height, fresh weight shoot protein contents leaves substantially improved Zn, however, plants growing treated absence only plant growth also showed necrotic symptoms on leaves. application decreased populations both root. A positive correlation between bacterial was observed. With increase densities soil, subsequent galling due to Meloidogyne javanica increased. Regardless densities, marked suppression M. At all population , enhanced efficacy invasion gall development. significant soil‐borne root‐infecting fungi Zn‐sufficient Zn‐deficient although this suppressive effect accentuated soils. In and/or increased shoots. regardless application. However, soils supported larger compared those