Abstract:
The present investigation on 'Influence of microflora associated with
earthworm (Eudrilus eugeniae Kinberg) and vermicompost on growth and
performance of chilli (Capsicum annuum L.) was done at College of
Agriculture, Vellayani during 1997-99 as part of a Science, Technology and
Environment Department (Government of Kerala) funded research project.
Among the surface microflora of Eudrilus eugeniae, the total number of
bacteria, fungi and actinomycetes were maximum on 45 day of compost
formation. However, the number of nitrogen fixing bacteria was more on 60
day. Similarly, in the case of gut micro flora, the total number of bacteria and
fungi were maximum on 45 day of composting. However, the number of
actinomycetes was more on 30 day. Nitrogen fixing bacteria could be isolated
only on 15 day.
In the vermicompost, the total number: of bacteria fungi and
actinomycetes were maximum on 30,45 and 60 day respectively. The number
of phosphate solubilizing bacteria and nitrogen fixing bacteria were more on
15 and 30 day of sampling. However, soilborne pathogens such as
Pseudomonas solanacearum, Pythium spp. and Phytophthora spp. were
absent.
There were significant differences in the growth rate of various isolates
of nitrogen fixing bacteria in Jensen's nitrogen free broth. The mean optical
density for isolate 3 was significantly higher than rest of isolates. The
nitrogen fixing ability of this isolate was also higher. The isolate 3 was
selected for enrichment of vermicompost. Based on various morphological
and physiological characters, this isolate was tentatively identified as
Azotobacter sp.
Among the different isolates of phosphate solubilizing bacteria, the
isolate 1 which showed maximum solubilization of tricalcium phosphate in
modified Pikovskaya's broth was selected for enrichment of vermicompost.
Based on the various morphological and physiological characters, the isolate 1
was tentatively identified as Pseudomonas sp.
In the study on the enrichment of vermicompost with nitrogen fixing
bacteria on growth of chilli, the shoot fresh and dry weights were significantly
high in the treatment combination receiving vermicompost enriched with
Azotobacter sp. along with 50 per cent nitrogen (N3P1K+VN) when compared
to the control treatment. The per plant yield was significantly high in the
treatment combination with 100 per cent nitrogen and vermicompost enriched
with Azotobacter sp. (NIP1K+VN) followed by that receiving 75 per cent
nitrogen and vermicompost enriched with Azotobacter sp. (N2P1K +VN).
In the study on the use of vermicompost enriched with phosphate
solubilizing bacteria, there were significantly earlier onset of flowering and
significantly higher number of fruits formed per plant in the treatment
combination of 100 per cent phosphorus along with vermicompost enriched
with Pseudomonas sp. There were no significant differences between
treatments in the keeping quality of chilli harvested from treatments with
enriched vermicompost.
III the interaction study between Eudrilus eugeniae or Megascolex sp.
and Pythium aphanidermatum, there was 100 per cent seedling mortality in
treatments such as. POP(F)+P and POP(V)+P where the application of
Pythium aphanidermatum was coupled with surface injury in the collar region
of seedlings. But in the absence of such an induced injury, there was no
incidence of damping off. However, in these treatments the plant growth was
generally poor in height, fresh and dry weight of roots. At the same time, the
plant growth was better in treatments without pathogen inoculation. The
number of branches formed was significantly high in POP(F)+E and
POP(V)+E treatments where Eudrilus eugeniae was applied when compared
to that of the control treatment.
The treatment with vermicompost alone (POP (V» recorded
significantly earlier onset of flowering. The number of fruits formed per plant
and per plant yield were significantly higher in the treatment with farm yard
manure and Eudrilus eugeniae (POP (F)+E) compared to the control.
Significant differences between treatments were observed in the onset
of flowering, number of fruits formed and in the per plant yield of chilli due to
the combined application of Megascolex sp. and Pythium aphanidermatum.
Flower initiation was earlier as well as the number of fruits formed were also
significantly high in the treatments with vermicompost either alone (POP (V»
or in combination with Megascolex sp. (POP(V)+M). The treatment with
vermicompost alone recorded the highest per plant yield.
There were no significant differences between treatments in the keeping
quality of chilli harvested from treatments with or without the application of
either Eudrilus or Megascolex sp. and Pythium aphanidermatum.