Agriculture Reference
In-Depth Information
inoculation of PSB. In summary, there was an overall improvement in average plant
height, plant canopy, and other measured yield parameters when the brinjal culti-
vars were inoculated with the PSB strains, indicating a clear-cut role of PS bacteria
in the development of eggplants (Roy and Sengupta
2008
).
12.4.2 Potato and Tomato
Globally, approximately 40 % of world's land has low crop production efficiency
especially for potato because its roots have limited access to P in the soil (Igual
et al.
2001
). Moreover, potato needs high amounts of P because of its high biomass
producing ability. In order to circumvent this P deficiency, chemical fertilizers are
used, but due to rapid fixation ability, P is not available for consumption by potato
plants. PSM here play an important role and supply P to potato by secreting certain
organic acids (Rashid et al.
2004
; Uma and Sathiyavani
2012
). Three PS bacterial
strains, namely,
Pantoea agglomerans
,
Microbacterium laevaniformans
, and
Pseu-
domonas putida
, when used singly or in combination against potato (
Solanum
tuberosum
), demonstrated a positive response under three sets of experiments,
i.e., laboratory, greenhouse, and fields. The combinations of either
P. agglomerans
or
M. laevaniformans
strains with
P. putida
led to higher biomass
and potato tuber growth in greenhouse and in field trials. This increase was
attributed to the fact that mixture of an acid- and a phosphatase-producing bacte-
rium might have allowed the simultaneous utilization of both inorganic and organic
P compounds by potato plants. On the contrary, the Pi levels of soil or application of
chemical Pi fertilizer, however, did not cause much difference in potato yields. Of
all the three PSB,
P. agglomerans
significantly increased the growth and yield of
potato plants by about 20-25 % (Malboobi et al.
2009
). Likewise, the dry weight of
creole potato roots, and the soil available N, showed better results with the
inoculation of 50 % of the inoculum consisting of PSB (
Pseudomonas cepacia
,
Xanthomonas maltophilia
,
Enterobacter cloacae
, and
Acidovorans delafieldii
, for-
merly called
P. delafieldii
) and four strains of
Azotobacter chroococcum
plus 50 %
of chemical fertilizer. A dual inocula of PSB and
A. chroococcum
resulted in
significant production of “criolla” potato, Yema de Huevo variety (
Solanum
phureja
), at a level matching that of crops grown solely with 100 % NPK fertilizer.
Furthermore, approximately 7.4 % reduction in costs of production was observed
following microbial inoculation (Faccini et al.
2007
). According to Naderi
et al. (
2012
) in a follow-up study, the tuber number per plant, stem number per
plant, and plant height of potato were not affected, but the PSB application had
significant effects on tuber formation (yield) and tuber mean weight. Leaf area
index (LAI), crop growth rate (CGR), and relative growth rate (RGR) were all
higher in the first stage of growth due to PSB application which further increased at
later stages of plant growth. Among all treatments, spraying PSB on the soil treated
with 100 kg/ha P chemical fertilizer displayed the best production of potato,
