Growth and survival of Trichoderma harzianum and Pseudomonas fluorescens on different substrates and their temporal and spatial population dynamics in irrigated rice ecosystem
221 / 217
Authors
-
O.P. GANGWAR*, P. SHARMA and U.D. SINGH
Keywords:
Antagonist, CFU, FYM, inoculants, rhizosphere, TrichodermaAbstract
Among the substrates and their combinations, soil+FYM (1:1) was found supporting maximum growth of both fungal and bacterial antagonists viz. 78.33×104 g-1 and 128.67×105 g-1 respectively. In inoculants, colony counts of P. fluorescens were high initially (12.3 ×108 g-1) which declined significantly with time whereas T. harzianum revealed stable survivability. Under protected conditions, population of T. harzianum and P. fluorescens reached maximum at 42 days after sowing viz. 11.17×104 g-1 soil and 7.48×106 g-1 soil, respectively and thereafter, declined sharply. In combined application, generally lesser population was observed than single treatment. In phyllosphere, population observed after foliar spray at weekly interval for a month. Both antagonists population increased initially and then decreased significantly. In field experiments, population of fungal and bacterial antagonists reached its pinnacle at 60 days after sowing. Population of bioagents was significantly higher in treated plot than that of check. Antagonistic population observed on rhizoplane revealed increasing trend upto flowering stage of rice crop. A significant negative correlation was observed between average pooled rhizosphere population of T. harzianum and disease intensity of bacterial leaf blight. In another experiment, the spatial population dynamics evaluated at differentiated depth levels (1, 5, 10 and 15 cm) in rice rhizosphere under open field conditions. It was observed that maximum population of antagonists existed near soil line (1-5 cm) and below 5cm depth, spore/cell counts reduced significantly.
Downloads
Issue
Section
License
For Authors
As soon as an article is accepted for publication, authors are requested to assign copyright of the article (or to grant exclusive publication and dissemination rights) to the publisher (Indian Phytopathlogical Society). This will ensure the widest possible protection and dissemination of information.
For Readers
While the advice and information in this journal is believed to be true and accurate at the date of its publication, the authors, the editors, nor the publisher can accept any legal responsibility for any errors or omissions that may have been made. The publisher makes no warranty, express or implied, with respect to the material contained herein.
All articles published in this journal are protected by copyright, which covers the exclusive rights to reproduce and distribute the article (e.g., as offprints), as well as all translation rights. No material published in this journal may be reproduced photographically or stored on microfilm, in electronic data bases, on video disks, etc., without first obtaining written permission from the publisher. The use of general descriptive names, trade names, trademarks, etc. in this publication, even if not specifically identified, implies that these names are protected by the relevant laws and regulations.