Induced systemic resistance by fluorescent pseudomonads against red rot disease of sugarcane caused by Colletotrichum falcatum

Abstract

Certain strains of fluorescent Pseudomonas spp. were studied for their plant growth promoting attributes and induced systemic resistance (ISR) against red rot pathogen Colletotrichum falcatum Went in sugarcane. The fluorescent pseudomonad (FPs) strains were applied three times in the field, initially as a sett treatment while planting and two soil applications in the field using talc-based formulations. The ISR effect in the treated canes was assessed by artificial inoculation of the pathogen in the cane stalks. Some Pseudomonas strains significantly reduced red rot disease intensity in the sugarcane stalks. The Pseudomonas-mediated ISR was significantly higher in the disease susceptible cultivars than in the moderately resistant and moderately susceptible cultivars. When five Pseudomonas strains were evaluated for their efficacy against the disease in an endemic location, isolates CHAO, EP1 and Pf1 significantly reduced disease incidence. The tested strains significantly improved vegetative sett germination and crop growth in the field. Less pathogen induced invertase enzyme activity was recorded in cane tissues from bacteria treated stalks, and higher juice characters viz. sucrose per cent and sugar yield as compared to the untreated stalk tissues, after pathogen inoculation. The efficacy of certain Pseudomonas strains against red rot pathogen, enhanced the yield of cane and sugar and this suggests that these bacterial strains may have a role to play in the management of red rot disease in sugarcane.