Effect of Azotobacter and Sphingobacterium species on guava seedlings under nursery conditions

Abstract

An experiment was planned to study the effect of biofertilizers, namely Azotobacter and Sphingobacterium species on guava seedlings under nursery conditions. The standard culture of Azotobacter and Sphingobacterium species was obtained from Department of Microbiology, Punjab Agricultural University, Ludhiana, Punjab, India. The liquid formulations of microbial inoculants were prepared by supplementing 2% PEG in basal medium. The three months old guava seedlings were given dip treatment for 30 mins with liquid microbial inoculants and transplanted in nursery bed and observations were recorded after one year. The treated guava seedlings showed very good response to Azotobacter and Sphingobacterium species treatment (T3) followed by Azotobacter sp. (T2). Seedlings inoculated with Azotobacter and Sphingobacterium species inoculation showed an increase of 4.28 per cent in shoot length, 4.41 per cent in collar diameter, 14.55 per cent in root length, 3.85 per cent in root numbers, 9.33 per cent in number of main branches/plant, 7.95 per cent in number of leaves, 6.95 per cent in fresh weight of shoot, 8.27 per cent in dry weight of shoot, 15.08 per cent in fresh leaf weight, 14.08 per cent in dry weight of leaves, 12.60 per cent in fresh weight of root and 12.69 per cent in dry weight of root over control. The use of biofertilizer offers better options for enhancing the vegetative growth of horticultural crops under nursery conditions in an increasingly eco-conscious world, thus increasing the success rate of vegetative propagation in healthy plants with well developed root and shoot system.