Biopriming rice seeds with biocontrol agents and liquid biofertilizers can improve seed germination and seedling vigor. The study found that priming seeds with Pseudomonas fluorescens at 60% concentration for 12 hours provided the best results, increasing seed germination rates and seedling growth. Primed seeds also maintained higher populations of beneficial microbes during storage, imbibed water faster, and were more tolerant of salt and drought stress conditions than unprimed seeds. Overall, biopriming seeds was found to enhance early seedling establishment and provide protection against pathogens and stress.

1. BIOPRIMING WITH BIOCONTROLAGENTS
AND LIQUID BIOFERTILIZERS FOR RICE
SEED cv. ADT 43
S. KAVITHA
&
K. VANANGAMUDI
Former Dean (Agriculture)
Tamil Nadu Agricultural University
Coimbatore 641 003

2. INTRODUCTION
• Rice (Oryza sativa L.) – 2nd largest produced cereal in the
World
• Production – 447.20 million tonnes
• Average productivity – 2852 kg ha-1
• ADT 43- Early duration variety
• Seed priming - controlled hydration
• Replacement or reduction - chemical application -
achieved through - biological - fungicides &
fertilizers
• Biocontrol agents - Pseudomonas fluorescens &
Trichoderma viride
• Liquid biofertilizers - Azospirillum & Phosphobacteria

3. 1. To standardize concentration and duration of
biopriming using biocontrol agents and liquid
biofertilizers for rice.
2. To determine the storability of bioprimed seeds
including seed health.
3. To study the pregerminative and postgerminative
physiological and biochemical changes of bioprimed
seeds during germination.
4. To evaluate the performance of bioprimed seeds under
stress conditions.
OBJECTIVES

4. METHODOLOGY
Biopriming agents
Concentration
(%)
Duration of soaking
(h)
Nonprimed seed - -
Hydropriming - 6, 12, 18 and 24
Trichoderma viride
40
6, 12, 18 and 24
60
80
Pseudomonas
fluorescens
40
6, 12, 18 and 24
60
80

5. Biopriming agents
Concentration
(%)
Duration of soaking
(h)
Azospirillum
10
6, 12, 18 and 24
15
20
Phosphobacteria
10
6, 12, 18 and 24
15
20
METHODOLOGY

6. RESULTS
STANDARDIZATION
Trichoderma viride – 60% 18h
Speed of germination (48h)
Control 60%18h

7. Germination %
74
77
80
83
86
89
92
95
6h 12h 18h 24h
Nonprimed Hydroprimed Trichoderma 40%
Trichoderma 60% Trichoderma 80%
Duration
Germination
(%)

8. VIGOUR INDEX
Control 60%12h
Seedling vigour on 5th day

9. Pseudomonas fluorescens – 60% 12h
Speed of germination (48h)
Control 60%12h

10. Germination %
70
75
80
85
90
95
6h 12h 18h 24h
Germination
(%)
Soaking duration
Nonprimed Hydropriming Pseudomonas 40% Pseudomonas 60% Pseudomonas 80%

11. Vigour index
9.5
10
10.5
11
11.5
12
6h 12h 18h 24h
Nonprimed Hydroprimed Pseudomonas40%
Pseudomonas60% Pseudomonas80%
Duration
Vigour
index

12. Seedling vigour on 5th day
Control 60%12h

13. Azospirillum 20% 12h
Speed of germination (48h)
Control 20%12h

14. Germination %
77
80
83
86
89
92
6h 12h 18h 24h
Nonprimed Hydroprimed Azospirillum10%
Azospirillum15% Azospirillum20%
Germination
(%)
Duration

15. Vigour index
Control 20%12h
Seedling vigour on 5th day

16. Phosphobacteria 15% 12h
Speed of germination (48h)
Control 15%12h

17. Germination %
77
80
83
86
89
92
6h 12h 18h 24h
Nonprimed Hydroprimed Phosphobacteria 10%
Phosphobacteria 15% Phosphobacteria 20%
Duration
Germination
(%)

18. Vigour index
Control 15%12h
Seedling vigour on 5th day

19. STORAGE STUDIES
Seed health (6th month)
A. Nonprimed; B. Hydropriming for12h; C. Trichoderma viride 60% for 18h; D. Pseudomonas
fluorescens 60% for 12h; E. Azospirillum 20% for 12h; F. Phosphobacteria 15% for 12h
After six months-best treatment- P.f. 60% 12h

20. Microbial population at initial month of storage
Trichoderma viride Pseudomonas fluorescens
Azospirillum Phosphobacteria

21. Trichoderma and Pseudomonas population at sixth month of
storage
T. viride P. fluorescens

22. PHYSIOLOGICAL STUDIES
Rate of Imbibition (%)
20
22
24
26
28
30
32
34
36
38
40
42
12h 24h 36h 48h
Nonprimed seed Hydropriming 12h
Trichoderma 60% 18h Pseudomonas60% 12h
Azospirillum20% 12h Phosphobacteria 15% 12h
Germination time
Imbibition
(%)

23. Seed metabolic efficiency and Germination % (60h)
87
88
89
90
91
92
93
94
95
96
0
0.03
0.06
0.09
0.12
0.15
0.18
0.21
0.24
0.27
0.3
0.33
0.36
0.39
Nonprimed seed Hydropriming 12h Trichoderma 60% for
18h
Pseudomonas 60% for
12h
Azospirillum 20% for
12h
Phosphobacteria 15%
for 12h
Seed metabolicefficiency Germination
Seed
metabolic
efficiency
Germination
(%)
Treatments

24. BIOCHEMICAL STUDIES
Activity of ∝-amylase (mg maltose min-1)
1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
0h 12h 24h 36h 48h
Nonprimed Hydroprimed Trichoderma 60% for 18h
Pseudomonas60% for12h Azospirillum 20% for 12h Phosphobacteria 15% for12h
Germination time

25. Starch content(mg g-1)
7.5
8
8.5
9
9.5
10
10.5
0h 12h 24h 36h 48h
Nonprimed Hydroprimed Trichoderma 60%for 18h
Pseudomonas60%for12h Azospirillum 20%for 12h Phosphobacteria 15%for12h
Germination time
Starch
content
(mg
g
-1
)

26. Reducing sugars (mg g-1)
0.2
0.25
0.3
0.35
0.4
0.45
0.5
0.55
0h 12h 24h 36h 48h
Nonprimed Hydroprimed Trichoderma 60%for 18h
Pseudomonas60%for12h Azospirillum 20%for 12h Phosphobacteria 15%for12h
Reducing
sugars
(mg
g
-1
)
Germination time

27. Peroxidase activity (Changes in absorbance at 470 nm min-1 g-1 fw)
1.2
1.7
2.2
2.7
3.2
3.7
0h 12h 24h 36h 48h
Nonprimed Hydroprimed Trichoderma 60%for 18h
Pseudomonas60%for12h Azospirillum 20%for 12h Phosphobacteria 15%for12h
Germination time
Peroxidase
(Changes
in
absorbance
at
470
nm
min
-1
g
-1
fw)

28. Polyphenoloxidase activity (Changes in absorbance at 470 nm min-1 g-1 fw)
1.4
1.9
2.4
2.9
3.4
3.9
0h 12h 24h 36h 48h
Nonprimed Hydroprimed Trichoderma 60%for 18h
Pseudomonas60% for12h Azospirillum 20%for 12h Phosphobacteria 15%for12h
Germination time
Polyphenoloxidase
(Changes
in
absorbance
at
470
nm
min
-1
g
-1
fw)

29. Phenylalanine ammonia lyase activity (nmol of
trans-cinnamic acid min-1 g-1 fw)
1600
1800
2000
2200
2400
2600
2800
3000
0h 12h 24h 36h 48h
Nonprimed Hydroprimed Trichoderma 60%for 18h
Pseudomonas60%for12h Azospirillum 20%for 12h Phosphobacteria 15%for12h
Phenylalanine
ammonia
lyase
(nmol
of
trans-cinnamic
acid
min
-1
g
-1
fw)
Germination time

30. NaCl salt stress
Control P. f 60%12h
1% NaCl
STRESS STUDIES

31. Germination of bioprimed rice seed under salt stress condition
70
75
80
85
90
95
0.25% 0.50% 0.75% 1.00%
Nonprimed Hydroprimed Trichoderma 60% for 18h
Pseudomonas60%for12h Azospirillum 20%for 12h Phosphobacteria 15% for12h
Germination
(%)
NaCl concentration

32. Water holding capacity
Seedling growth under 20% water holding capacity on 5th day of
germination
Nonprimed P. f 60% 12h

33. Germination % under different water holding capacity
78
81
84
87
90
93
96
99
20% 40% 60% 80%
Nonprimed Hydroprimed Trichoderma 60%for 18h
Pseudomonas60%for12h Azospirillum 20%for 12h Phosphobacteria 15%for12h
Water holding capacity
Germination
(%)

34. CONCLUSION
• Pseudomonas fluorescens 60% 12h - Best
• Priming effect – fast imbibition, early emergence, increase
in population of bioprotectants, rapid and uniform seedling
emergence, water and nutrient uptake, protection against
pathogens, tolerate stress conditions and good storability.