Evaluation of Lettuce and Tomato Varieties- Plant
Growth Promoting Rhizobacteria (PGPR)
Interaction Under Upland And Lowland Conditions
January 2008 – June 2009
Basic Information
Project Leader: Evelyn F. Delfin
Implementing Agency: IPB-CSC, CA, UPLB
Funding Agency: PCARRD-DOST
Duration:
Date Started: January 1, 2008
Date Completed: June 30, 2009
Significance of the Study
Increasing crop productivity through heavy
fertilizer and pesticide inputs were expensive
not only in terms of economic investment but
also because of their adverse effect on the
environment
Importance of microbial communities that
interact with plants on plant health,
productivity and biodiversity
Significance of the Study
Plant Growth Promoting Rhizobacteria (PGPR)
were found capable of promoting plant growth
through increased root length and volume
BIOTECH, UPLB developed a PGPR inoculant
for vegetable crops with the trademark
‘BioGroe’.
Need to determine the presence of interaction
of different varieties of tomato and lettuce with
PGPR inoculation.
Objective:
To evaluate lettuce and tomato varieties- plant
growth promoting rhizobacteria (PGPR)
interaction under upland and lowland
conditions
Accomplishments
Conducted replicated field
trials
Lettuce – evaluated 9
varieties – DS 2008
Tomato – evaluated 10
entries
UPLB – DS and WS 2008
Lowland – DS 2008
Triton M1Green Tower Parris Island
Tyrol Craquelle du Midi
Lettuce varieties evaluated
Corelle
Lollo RosaGreen Span
Falbala
Lettuce varieties evaluated
Lettuce
Lack of significant treatment * variety interaction was obtained in terms of marketable yield , dry matter yield, root/shoot ratio and nutrient uptake although different treatment – variety combinations showed a wide range of response among varieties to inoculation
Significant Treatment *Variety Interaction was obtained in terms of average plant weight and P content
0
25
50
75
100
125
150
175
200
L B
ata
via
Lo
llo
Ro
sa
Co
rell
e
Fa
lba
la
Gre
en
sp
an
Pa
rris
Isl
an
d
Gre
en
To
we
r
Ty
rol
Cra
qu
ell
e d
u M
idi
Tri
ton
M1
Pla
nt
weig
ht,
g p
lan
t-1
Inoculated
Control
* 33%* 39%
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
L B
ata
via
Lo
llo
Ro
sa
Co
rell
e
Falb
ala
Gre
en
sp
an
Parr
is I
slan
d
Gre
en
To
wer
Ty
rol
Cra
qu
ell
e d
u M
idi
Tri
ton
M1
Ph
osp
ho
rus
con
ten
t %
Inoculated
Control
* 17% *21%
Field Evaluation – Tomato
UPLB, DS and WS 2008
Experimental Layout: Split-split plot design with 3 reps
Main plot – Fertilizer Rate
Subplot – Inoculation
Sub-sub plot - varieties
Plot size : 4 m x 3 m. 0.40 m distance between hills, 0.75 m distance between rows
Fertilization: Full Fertilizer Rate – 93-46-113 kg NPK ha-1;
Half Fertilizer Rate : 46.5-23-56.5
Basal application - 10 g complete fertilizer per plant
Sidedress– 10 g (6.67 g Ammonium Sulfate and 3.33 g Muriate of Potash)
Tomato varieties
Open Pollinated
Northern Red
Improved Apollo
Caraibo
Rossana
Discovery
Hybrid Variety
Assunta
Rocky/Diamante
Mt. Fresh
Antares
Atlas
Results
Agronomic Characteristic:
Significant fertilizer –inoculation treatment interaction
– number of branches, number of flower cluster
with inoculation , number of branches - increased by 29%
under half fertilization rate (HFR)
30% increase in number of flower clusters due to
inoculation observed under HFR from 10 to 13 clusters
Significant group-inoculation interaction – flower
clusters formed
Inoculation increased number of flower clusters among OP
varieties from 11 to 13 clusters –15% increase
Number of primary branches of inoculated and
uninoculated tomatoesat two fertilizer levels.
0
1
2
3
4
5
6
7
8
9
Nu
mb
er
of
Pri
mary
Bra
nch
no
pla
nt-1
HRR FRR
Fertilizer Application
Uninoculated
Inoculated
a
a a
b
29% increase in number of primary branches with
inoculation under Half Fertilization Rate
Number of flower clusters of inoculated and uninoculated
tomatoes at two fertilizer levels
0
2
4
6
8
10
12
14
Nu
mb
er
of
Flo
wer
Clu
ste
r
no
pla
nt-1
HFR FFR
FERTILIZER RATE
Uninoculated
Inoculated
b
a
a a
30% increase in no of flower clusters due to
inoculation observed under HFR from 10 to
13 clusters
Number of flower clusters of inoculated and uninoculatedOP and hybrid tomatoes.
Inoculation increased number of flower clusters among
OP varieties from 11 to 13 clusters –15% increase
0
2
4
6
8
10
12
14
Nu
mb
er
of
Flo
wer
Clu
ste
r
no
pla
nt-
1
Open Pollinated Hybrid
Tomato Group
Uninoculated
Inoculated
b
a
aa
Significant fertilizer – inoculation treatment-
variety interaction – flower dry weight and root dry
weight
Root dry weight – inoculation increased root dry
weight of Northern Red, Improved Apollo and
Discoveryby 37-83% under HFR
Under FFR , only Improved Apollo showed significant
increase in root dry weight
0.00
1.00
2.00
3.00
4.00
Ro
ot
dry w
eig
ht,
g
pla
nt-
1
Half-Fertilizer Rate
Control
Inoculated
**
*
0.00
1.00
2.00
3.00
4.00
No
rth
ern
Re
d
Imp
roved
Ap
ollo
Cara
ibo
Ro
san
na
Dis
co
very
Ass
un
ta
Ro
cky
Mt.
Fre
sh
An
tare
s
Atl
as
Ro
ot
dry w
eig
ht,
g p
lan
t-1
Variety
Full Fertilizer Rate
Control
Inoculated
*
Fruit Yield
Due to problems with various plant diseases such as
virus and bacterial wilt few plants survived up to
maturity
Such that fertilization and inoculation effects were
not significant , although the Hybrids had higher
yield than OPs in general
Varieties evaluated differed significantly in terms of
yield
WET SEASON EVALUATION
Agronomic Characteristics
Significant fertilizer-inoculation-variety interaction –
number of branches formed
Improved Apollo showed a significant 33% increase in
the number of branches formed due to inoculation for both
fertilization rates while Rosanna had a remarkable 40%
increase with half-fertilizer rate.
Significant 33% increases were obtained for Discovery
and Mt. Fresh with full fertilizer rate applied.
0
1
2
3
4
5
6
7
8
Inoculated
Control
*
0
1
2
3
4
5
6
7
8
No
rth
ern
Red
Imp
roved
Ap
ollo
To
mato
Cara
ibo
Ro
ssan
a
Dis
covery
Ass
un
ta
Dia
man
te
Mt.
Fre
sh
An
tare
s
Atl
as
Inoculated
Control
* * *
Branches plant-1
Half-Fertilizer
Full Fertilizer
*
In terms of number of flower clusters formed, inoculation
increased the flower clusters of Rossana by 60% increase
under half-fertilizer rate treatment
Caraibo, Discovery and Atlas showed remarkable increase
in the number of flower clusters formed with full fertilizer
rate applied
Significant fertilizer-inoculation-variety interaction –
number of flower clusters formed
0
2
4
6
8
10
12
No
rth
ern
Red
Imp
roved
Ap
ollo
To
mato
Cara
ibo
Ro
ssan
a
Dis
co
very
Ass
un
ta
Dia
man
te
Mt.
Fre
sh
An
tare
s
atl
as
Inoculated
Control
*
*
*
0
1
2
3
4
5
6
7
8
Inoculated
Control
* * * Half Fertilizer Rate
Full Fertilizer Rate
Number of flower clusters
no plant-1
Significant inoculation treatment-variety interaction -
above ground dry matter , root dry weight and root shoot
ratio
PGPR inoculation also increased above ground dry matter
and root dry weight of hybrid variety, Antares by 26 and
21%, respectively whereas the other entries did not respond
to inoculation across fertilizer rates.
The increase in root dry weight due to inoculation also
increased the root shoot ratio of OP varieties, Northern Red
and Improved Apollo.
Inoculation increased P content of the evaluated varieties
from 0.20 to 0.21% P which also resulted to enhanced P
uptake.
Differences in N and K uptake in response to different
treatment combinations were not observed.
Nutrient Uptake
PGPR inoculation significantly increased the total
yield of OP variety, Rosanna and hybrid Variety, Atlas
With inoculation, the total fruit weight of Rosanna was
increased by 27% while Atlas showed 19% increase
Yield
0
100
200
300
400
500
600
700
No
rth
ern
Red
To
mato
Cara
ibo
Ro
ssan
a
Dis
covery
Ass
un
ta
Dia
man
te
An
tare
s
Atl
asA
vera
ge f
ruit
weig
ht,
g p
lan
t-1
Inoculated
Control
* 27 %
Lowland Evaluation
Experimental Layout: Split plot design with 3 reps
Main plot – Inoculation
Subplot - varieties
Plot size : 4 m x 3 m. 0.40 m distance between hills, 0.75 m distance
between rows
Fertilization: Full Fertilizer Rate – 71-46-112 kg NPK ha-1
Basal application -
Sidedress–
Results
Significant Treatment*Variety Interaction – Flower
Dry Weight and Shoot Dry Matter Yield
Assunta and Atlas significant increase in flower dry weight
Assunta had significant increase in shoot dry matter yield
due to inoculation
Yield data were not obtained from the trial because of the
heavy rains in May which flooded the field trial
Shoot Dry Matter Yield
0
1
2
3
4
5
6
7
8
No
rth
ern
Red
Imp
roved
Ap
ollo
Cara
ibo
Ro
ssan
a
Ass
un
ta
Ro
cky
Mt.
Fre
sh
An
tare
s
Atl
as
Sh
oo
t d
ry w
eig
ht,
g p
lan
t-1
Inoculated
Control
*
With the evident response of certain tomato and lettuce
varieties to PGPR inoculation, trials should be
conducted at different locations to validate the results
of the on-station field evaluation.
Recommendation