Evaluation of indigenous Azospirillum isolates for growth promotion in black pepper (Piper nigrum L) rooted cuttings

Abstract

The aim of the present work was to evaluate the inoculation effects of indigenous Azospirillum spp. selectively isolated from various black pepper growing locations of Kerala and Karnataka in enhancing the growth and nutrient uptake of black pepper cuttings. Azospirillum isolates BPaz4 and BPaz9 recorded 67% more plant height in rooted cuttings than untreated cuttings. The nitrogen, phosphorus and potassium uptake and total dry weight was significantly superior in treated plants. Increase in the uptake of iron, manganese, zinc and copper was found in BPaz9 treatment. Colonization of rhizosphere soil and nonrhizosphere by these isolates was found to be high. The N2-fixation capacity of the isolates BPaz4 and BPaz9 showed 8.68 and 8.52 mg g-1 malate. Thus the application of these inoculants viz. BPaz4 and BPaz9 is suggested for the ecofriendly production of rooted cuttings of black pepper.