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

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Inoculated

Control

* 33%* 39%

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

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Ph

osp

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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