Agriculture Reference
In-Depth Information
waste derived vermicompost showed presence of signifi cant amounts
indole-acetic-acid (IAA), gibberellins and cytokinins (Edwards et al.
2004).
Earthworm gut associated microbes enrich vermicomposts with
highly water-soluble and light-sensitive plant growth hormones, which
gets absorbed on humic acid substances in vermicompost making them
extremely stable and helps them persist longer in soils thereby infl u-
encing plant growth (Atiyeh et al. 2002; Arancon et al. 2003c). This is
confi rmed by presence of exchangeable auxin group in the macrostruc-
ture of humic acid extract from vermicompost (Canellas et al. 2002).
Apart from the rich nutritional status and ready nutrient availability,
presence of humic acids and plant growth regulating substances makes
vermicompost a biofertilizer which increases germination, growth,
fl owering and fruiting in a wide range of crops. Vermicompost substi-
tution in a relatively small proportion (10-20%) to the potting mixture
increased dry matter production and tomato growth signifi cantly (Sub-
ler et al. 1998). Soil amended with 20% vermicompost was more suit-
able for tomato seedling production (Valenzuela et al. 1997). Similarly
vermicompost addition upto 50% in the medium resulted in enhanced
growth of
Chamaecyparis lawsoniana
(Lawson's Cypress),
Juniperus
communis
(Juniper) and
Elaeagnus pungens
(Silverberry) rooted liners
(Bachman and Edgar Davice 2000).
Vermicompost application increased plant spread (10.7%), leaf
area (23.1%), dry matter (20.7%) and increased total strawberry fruit
yield (32.7%) (Singh et al. 2008). Substitution of vermicompost dras-
tically reduced the incidence of physiological disorders like albinism
(16.1-4.5%), fruit malformation (11.5-4.0%) and occurrence of grey
mould (10.4-2.1%) in strawberry indicating its signifi cance in reduc-
ing nutrient-related disorders and Botrytis rot, thereby increasing the
marketable fruit yield upto 58.6% with better quality parameters. Fruit
harvested from plant receiving vermicompost were fi rmer, had higher
total soluble solids (TSS), ascorbic acid content and attractive colour.
All these parameters appeared to be dose dependent and best results
were achieved at 7.5 t ha
-1
(Singh et al. 2008). Vermicompost application
showed signifi cant increase in germination percent (93%), growth and
