EFFECT OF A PLANT-GROWTH PROMOTING BACTERIUM, AN AM FUNGUS AND SOIL TYPES ON THE MORPHOMETRICS AND REPRODUCTION OF MELOIDOGYNE-JAVANICA ON TOMATO

The effects of a plant growth promoting bacterium Pseudomonas fluoresc ens. an AM fungus Glomus mosseae and different soil types (having a mi xture of clay:sand into 4:0, 3:1, 2:2, 1:3 and 0:4) were studied on th e growth of tomato plants and on the: reproduction of Meloidogyne java nica and morphometrics of nematode females. Combination of clay and sa nd of 3:1 gave best plant growth response followed by combination of 4 :0 and 2:2 of clay:sand. Use of G. mosseae or P. fluorescens in differ ent soil types caused significant increase in plant growth except in p lants grown in pure sand. Use of G. mosseae or P. fluorescens both in uninoculated and nematode inoculated plants caused almost similar incr ease in plant growth but the combined use of both organisms caused gre ater increase in plant growth than when used singly. Plants grown in p urr sand had the least galling and nematode reproduction. Moreover, pl ants grown in a mixture of clay and sand of 1:3 supported highest fall ing and nematode reproduction, followed by 2:2 and 3:1 clay:sand ratio . Applications of G. mosseae or P. fluorescens caused reduction in fal ling, nematode reproduction and morphometric parameters of females. Co mbined use of both organisms caused higher reduction in galling, nemat ode reproduction and morphometrics than their individual application. All the parameters of morphometrics observed showed reduction in their size except stylet length and styler knob width. AM colonization was best in plant roots grown in 3:1 clay:sand ratio and least when grown in pure sand. (C) 1998 Elsevier Science B.V. All rights reserved.