TY  - BOOK
AU  - Anju A B
AU  - K N Anith (Guide)
TI  - Plant growth promotion and foot rot disease management in black pepper by bacillus spp
U1  - 660.62 
PY  - 2022///
CY  - Vellayani
PB  - Department of Agricultural Microbiology, College of Agriculture
KW  - Agricultural Microbiology
KW  - Black pepper
KW  - Rot disease
N1  - MSc
N2  - The study named “Plant growth promotion and foot rot disease management 
in black pepper by Bacillus spp.” was conducted in Department of Agricultural 
Microbiology, College of Agriculture, Vellayani and Coconut Research Station, 
Balaramapuram, during the academic year 2019-2022. The objective of the study
was to assess the effects of endospore-forming Bacillus spp. on growth and foot rot 
disease suppression in black pepper in the nursery.
Experiments comprised both in vitro and in vivo studies. In in vitro
interaction, dual culture plate assay was done to assess the antagonistic effect of 
bacterial isolates against P. capsici.
All the three bioagents used were proven to be antagonistic to P. capsici. B.
pumilus VLY17 showed the maximum zone of inhibition whereas B. 
amyloliquefaciens VLY27 showed the least zone of inhibition. No inhibition on 
mycelial growth of P. capsici was observed on treatment with culture filtrate in agar 
well diffusion assay.
In detached leaf assay screening, significant difference was observed in 
lesion size developed on leaves treated with bacterial suspension compared to that 
on control leaves treated with sterile water. On 2DAI, leaves dipped in B. pumilus
VLY17 showed the least lesion size whereas on 3 DAI, leaves applied with 
consortium of the bacterial isolates showed the least lesion size. 
Bio agents were characterized to check the production of plant growth 
promoting and disease suppressing metabolites. All the three isolates showed 
significant amount of IAA production. B. velezensis PCSE10 produced higher IAA 
(15.10 ppm) when estimated without adding tryptophan whereas B.
amyloliquefaciens VLY27 produced maximum IAA (23.34 ppm) when medium 
was supplemented with L-Tryptophan. None of the strains could produce HCN 
under in vitro conditions. B. amyloliquefaciens VLY27 and B. velezensis PCSE10 
used produced Ammonia. None of the bacterial isolates used showed siderophore 
production and phosphate solubilization. 
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Bacterization with B. pumilus VLY17 showed the maximum establishment 
of cuttings, maximum number of leaves per plant, maximum shoot length and 
longest root length, maximum root volume and maximum fresh weight and dry 
weight of newly emerged shoot and leaves as well as roots throughout the 
experimental duration. Even though fresh weight of roots increased on 
bacterization, no significant difference was observed in statistical analysis 
compared to control. Plants treated with B. amyloliquefaciens VLY27 showed the 
maximum number of roots per plant. 
Suppression of Phytophthora foliar infection on bacterization was 
evaluated in the nursery. On analysis significant difference was observed in lesion 
size on treatment with bacterial suspension compared to pathogen inoculated 
control. The least lesion size was observed on treatment with B. pumilus VLY17. 
The treatments also showed significant effect on disease index. 
Abundance of root colonization by endospore forming bacterial isolates was 
checked to ascertain if the plant growth promotion as well as the disease 
suppression was brought about by the endospore-forming bacterial isolates. 
Colonization of endospore formers was found to be maximum on roots of plants 
treated with consortium of bacterial isolates.
From the present study, it is concluded that endospore-forming bacteria used 
in the study have plant growth promotional activities and biocontrol potential
against the pathogen P. capsici, which causes foot rot in black pepper.

ER  -