Studies On The Host Defense Enzymes Produced In Rice By Application Of Organic Formulations And Sheath Blight Pathogen Inoculation

Abstract

Organic formulations against rice sheath blight disease are gaining momentum and encompasses all available control methods with each method compensating the deficiencies of other disease management practices. Combined use of biological and seaweed extracts are an important effective against sheath blight disease caused by Rhizoctonia solani .Pot culture experiments were conducted with various organic formulation alone. The different organic formulations (viz., T 1 -Pseudomonas fluorescens( ST), T 2 -Sargassum wightii ( ST) , T 3 = T 1 + T 2 (ST) , T 4 -Sargassum wightii ( spray) , T 5 = Sargassum wightii+ Pseudomonas fluorescens ( spray) , T 6 =T 3 + T 5 , T 7 -control) were tested against sheath blight disease incidence and growth and yield attributes in rice under greenhouse condition . Among the treatments, (T 6 = T 3 +T 5 ) recorded the least sheath blight incidence and increase the bio metrics and yield characters. Rice plants treated with T 6 followed by challenge inoculation with R. solani gave a maximum induction of β-1, 3-glucanase activity on 5th day after pathogen inoculation and declined thereafter, maximum peroxidase activity at 7th day after pathogen inoculation then declined slowly, polyphenol oxidase activity on the 7 th day and thereafter declined. Maximum activity of phenylalanine ammonia lyase activity was observed on the 7 th day of inoculation.