Agriculture Reference
In-Depth Information
tions reflect synergistic lifestyles facilitating more effective and efficient
growth and biogeochemical cycles than individual populations as a com-
munity. Such associations are often called microbial consortium in which
members of the consortium maintain metabolic and ecological compat-
ibility for individual niches to exist in the close proximity in soil (Radi-
aningtyas et al., 2003, Lazdunski et al., 2004). Such microbial consortium
is more resistant to environmental changes, and can compete much better
than single microorganism. As a result different species of microbial con-
sortium inside an ecosystem propagate with different dynamics depending
upon their genetic potentiality as well as capacity of adjustment to the
microenvironmental conditions giving better yield and quality (Bashan,
1998). If the microorganisms interactions are evaluated and included in
such selection process, a microbial consortium may out-perform the re-
sults achieved by pure cultures. When different microbial strains are made
into an inoculum consortium, each of the constituent stains of the consor-
tium not only out-compete with others for rhizosphere establishments, but
complement functionally for plant growth promotion (Wu and Srivastava,
2012). Different microbial components in a microbial consortium should
possess:
1. high rhizosphere competence,
2. high competitive saprophytic ability,
3. ease for mass multiplication,
4. safe to environment,
5. broad spectrum of action,
6. excellent and reliable efficacy,
7. compatible with other rhizosphere microbes, and in able to tolerate
other abiotic stresses (Date, 2001; Rainey, 1999).
The developed microbial consortium (containing
Bacillus polymyxa,
Bacillus mycoides, Pseudomonas fluorescens, Azotobacter chroococcum
and
Trichoderma harzanium
) was evaluated in nursery plants, both on
seedlings for 45 days and in buddlings for 124 days, using a total of 354
plants. Out of these 354 plants, 172 plants in 13 replications (each with
4 units) were treated and other 172 plants in 13 replications were kept as
untreated control
(
Table 11.5
).
The response of microbial consortium on
rough lemon seedlings showed a significant increase in various growth
parameters (9.59 g root weight, 24.86 g shoot weight, and 11.9 mm stem
diameter on per plant basis) over control (2.99 g root weight, 9.08 g shoot
weight, and 8.6 mm stem diameter on per plant basis). Similar obser-
