Effect of pre-sowing treatments on seed germination ...

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Progressive Horticulture, Vol. 45, No. 1, March 2013

Progressive Horticulture, Vol. 45, No. 1, March 2013 © Copyright by ISHRD, Printed in India

[Research Article]

Effect of pre-sowing treatments on seed germination of guava (Psidium guajava L.) under Tarai region of Uttarakhand Manoj Brijwal, Rajesh Kumar and D.S. Mishra Department of Horticulture, G.B. Pant University of Agriculture and Technology Pantnagar, 263 145, Uttarakhand Email: [email protected]

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ABSTRACT A field experiment was conducted to study the effect of pre-sowing treatments on seed germination of guava (Psidium guajava L.). Treatments were imposed under two variable conditions viz., open field and polyhouse. The objective of the study was to get healthy seedling rootstocks with highest survival percentage in minimum possible time. There were 24 treatment combinations which were replicated thrice. Seeds scarified with 10% hydrochloric acid for 2 minutes were found to be the best one with very high seed germination percentage (54.16%), seed vigour index (196.48), survival percentage of seedlings (93.59%) and takes minimum time to obtain mean germination (24.95 days). Scraping of seed coat with sand paper + seeds soaked in GA3 at 50 ppm for 24 hours resulted in the maximum relative elongation rate (0.088 cm) of seedlings. All the germination parameters were found best in protected environment (viz. polyhouse) as compared to open field conditions. Sowing of seeds without pre-sowing treatment showed poor germination (23.50%) and survival percentage (74.30%). KEY WORDS: Guava, pre-sowing treatments, rootstock, seed germination

Guava (Psidium guajava L.), a member of family Myrtaceae, is an important fruit of tropical and subtropical regions of the world. Guava occupies an area of 205 thousand hectares in India with approximate production of 2462 thousand metric tonnes (Anonymus, 2011). Maharashtra ranked first in area (36 thousand hectares) and production (311 thousand metric tonnes), however, maximum productivity (29 metric tonnes per hectares) was recorded in Madhya Pradesh. As the area under guava is increasing day by day, the demand of budded plants are also increasing. The demand is not fulfilled because of unavailability of superior seedling rootstocks which might be due to poor seed germination and seedling growth. Guava seeds germinate poorly and unevenly and require more time for seedling emergence (Doijode, 2001). The dormancy in seeds might be due to hard seed coat and impermeability to water and gases. Different methods like water soaking, scarification and chemical treatments are used for breaking dormancy in seeds to improve germination. Hence the present

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studies were undertaken to standardize the pre-sowing treatments for raising seedling rootstocks of guava.

MATERIALS AND METHODS The present investigation was carried out at Horticultural Research Centre, Patharchatta, Department of Horticulture, Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, Uttarakhand in the year 2011-12. The experiment was laid out in two factorial randomized block design (RBD) with twelve treatments, viz., seeds soaked in tap water for 24 hours (T1), seeds soaked in tap water for 48 hours (T2), scraping of seed coat with sand paper (T3), scraping of seed coat with sand paper + seeds soaked in GA3 50 ppm for 24 hours (T4), scraping of seed coat with sand paper + seeds soaked in GA3 100 ppm for 24 hours (T5), seeds soaked in 5% hydrochloric acid for 2 minutes (T6), seeds soaked in 10% hydrochloric acid for 2 minutes (T7), seeds soaked in 5% sulphuric acid for 2 minutes (T8), seeds soaked in 10% sulphuric acid for 2 minutes (T9),





seeds soaked in 0.1 % potassium hydroxide for 2 minutes (T10), seeds soaked in 0.2 % potassium hydroxide for 2 minutes (T11) and control (T12). Each treatment replicated thrice in two environments viz., open field (E1) and polyhouse (E2). A set of 5 seedlings in each treatment were selected replication wise. The seeds which sank were used for sowing and rest were discarded. Hundred seeds per replication were sown in nursery beds in both open field and polyhouse conditions. After sowing, the beds were covered with dry grasses, till the germination started light irrigation was provided in the morning and evening every day. The dry grasses were removed after germination started. Observations on seed germination percentage, number of days required for seed germination, mean germination time (days), seed vigour index, relative elongation rate (cm) and survival percentage of seedlings were recorded at 30 days interval after sowing.

RESULTS AND DISCUSSION a) Seed germination percentage The data on seed germination percentage revealed that different pre-sowing treatments, environments and their interaction significantly affected the seed germination percentage of guava (Table 1). The maximum germination percentage (56.00%) at 45 days after sowing was recorded in seeds treated with 10% hydrochloric acid for 2 minutes (T7E2) followed by (50.33%) in scraping of seed coat with sand paper (T3E2) both of which were significantly superior to other treatments. The minimum germination percentage (19.66%) was recorded from the seeds soaked in tap water for 24 hours (T1E2). Under open field, significantly the maximum germination percentage (52.33%) at 45 days after sowing was recorded in the seeds treated with 10% hydrochloric acid for 2 minutes (T7E1) followed by (43.66%) in 0.1% potassium hydroxide for 2 minutes (T10E1) and the minimum germination percentage (23.66%) was recorded in control (T12E1). However, seeds sown in polyhouse gave higher (36.00%) germination percentage than the seeds sown in open field (33.94%). The results highlighted that the seeds of guava possesses physical dormancy. Seeds treated with 10% concentrated hydrochloric acid for 2 minutes (T7) gave maximum germination percentage (54.16 %) as compared to rest of the treatments indicating that treating guava seeds in 10% concentrated hydrochloric acid for 2 minutes improves the germination percentage. This was possibly due to stimulating effect of acid scarification brings about the softening of hard seed coat by dis-

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solution of deposited lipids, pectic substances and high density waxes which are responsible for hard seededness. This in turn makes the seed permeable to water and gases and induces germination (Denny, 1917). The minimum germination percentage (23.50 %) in control was possibly due to reduced permeability of seed coat to water and dissolved gasses (Crocker, 1953). These results are in close conformity with the finding of Singh and Soni (1974) as they reported that soaking of seeds of Allahabad Safeda in hydrochloric acid, sulphuric acid and nitric acid for 2-3 minutes improved the germination counts over control. b) Number of days required for seed germination The different pre-sowing treatments had a significant effect on number of days required for seed germination but the environment and interaction effect did not differ significantly (Table 1). The seeds subjected to 10% hydrochloric acid for 2 minutes (T7E2) recorded minimum number of days (13.66) required for seed germination followed by seeds treated with 10% sulphuric acid for 2 minutes (T8E2) recorded 14 days and the maximum number of days (16) required for seed germination was recorded in seed soaked in tap water for 48 hours (T2E2) in polyhouse, whereas, in open field seeds treated with 10% hydrochloric acid for 2 minutes (T7E1) took significantly minimum number of days (15) for germination initiation which was followed by 10% sulphuric acid for 2 minutes (T8E1) recorded 15.33 days. Maximum number of days (17.66) required for seed germination was recorded in control (T12E1). Seeds sown in polyhouse recorded minimum number of days (14.80) required for seed germination than the seeds sown in open field (15.86). In the present study, the minimum number of days required for seed germination in case of acid scarified seeds might be due to the softening of hard seed coat which resulted in minimum time required for germination as also reported by Chattopadhyay and Dey (1992). These results are in accordance with the findings of Hayes (1953) as he reported that acid scarification of guava seeds shortened the time required for germination without any adverse effect on germination percentage. c) Mean germination time The data on mean germination time reveal that different pre-sowing treatments, environments and their interaction significantly affected the mean germination time of guava seeds (Table 1). In polyhouse, the minimum mean germination time (23.29 days) of seeds was recorded in seeds treated with 10% hydrochloric acid for 2 minutes (T7E2) and the maximum mean germina-


23.66 33.94 Env. (E)

T12 (Control)

Mean

1.03

27.66

T11 (0.2 % Potassium Hydroxide for 2 minutes)

S.Em.±

43.66

T10 (0.1 % Potassium Hydroxide for 2 minutes)

2.95

Treat. (T)

34.66

T9 (10% Sulphuric acid for 2 minutes)

C.D. at 5%

36.00

31.33


2.54

7.24

23.33

42.66

34.33

39.33

39.00

56.00

52.33

T7 (10% Hydrochloric acid for 2 minutes)

40.66

24.00

37.33

24.00

30.33

50.33

32.33


GA3 100 ppm for 24 hours )

T5 (Scraping of seed coat with sand paper +

GA3 50 ppm for 24 hours)

34.33

36.33

T3 (Scraping of seed coat with sand paper)


24.00

T2 (Seeds soaked in tap water for 48 hours)

19.66

(E2)

(E1) 38.00

Polyhouse

Open field


Treatments

3.59

10.24

E×T

34.97

23.50

35.16

39.00

37.00

35.16

54.16

39.00

24.00

32.33

43.33

28.16

28.83

Mean

Seed germination percentage

0.10

NS

Env. (E)

15.86

17.66

16.00

15.66

15.33

15.66

15.00

15.66

16.00

16.00

15.66

15.66

16.00

field (E1)

0.25

0.71

Treat. (T)

14.80

15.66

14.33

14.66

14.00

14.33

13.66

14.66

15.33

15.00

14.66

16.00

15.33

(E2)

Polyhouse

0.35

NS

E×T

15.33

16.66

15.16

15.16

14.66

15.00

14.33

15.16

15.66

15.50

15.16

15.83

15.66

Mean

0.36

1.03

Env. (E)

30.71

38.32

32.10

30.20

29.09

27.33

26.60

27.45

34.82

34.00

26.28

30.56

31.80

(E1)

Open field

0.89

2.54

Treat. (T)

29.34

35.42

26.70

30.85

29.77

27.57

23.29

27.84

28.65

32.32

26.48

32.55

30.68

(E2)

Polyhouse

1.26

3.59

E×T

30.03

36.87

29.40

30.52

29.43

27.45

24.95

27.64

31.74

33.16

26.38

31.56

31.24

Mean

(days)

seed germination Open

Mean germination time of seeds

Number of days required for

Table 1: Effect of pre-sowing treatments on seed germination percentage, number of days required for seed germination and mean germination time of guava seeds



65 Progressive Horticulture, Vol. 45, No. 1, March 2013


96.48 109.52



NS 4.64

S.Em.±

11.36

32.36

Treat. (T)

Env. (E)

C.D. at 5%

141.57

106.92

Mean

62.23

149.00

44.49

81.78

144.04

151.40

155.62

226.68

160.29

117.41

147.23

195.66

120.77

T12 (Control)

minutes)

T11 (0.2 % Potassium Hydroxide for 2

minutes)

139.12

166.28


T10 (0.1 % Potassium Hydroxide for 2

115.75

96.12


GA3 100 ppm for 24 hours )


GA3 50 ppm for 24 hours)

138.42

116.98

T3 (Scraping of seed coat with sand paper)


74.03


68.56

(E2)

(E1) 104.07

Polyhouse

Open field


Treatments

Seed vigour index

16.07

45.76

E×T

124.24

53.36

115.39

141.58

130.46

126.05

196.48

138.02

106.76

142.82

156.32

97.40

86.31

Mean

0.001

NS

Env. (E)

0.054

0.035

0.037

0.052

0.065

0.056

0.044

0.047

0.065

0.082

0.057

0.064

0.050

(E1)

0.004

0.012

Treat. (T)

0.070

0.050

0.062

0.084

0.078

0.072

0.074

0.072

0.098

0.093

0.055

0.057

0.051

(E2)

Polyhouse

0.006

0.017

E×T

0.062

0.043

0.049

0.068

0.071

0.064

0.059

0.059

0.081

0.088

0.056

0.061

0.051

Mean

1.29

3.70

Env. (E)

84.41

74.44

80.75

80.41

88.04

91.74

92.07

83.33

75.80

85.90

91.16

78.07

91.22

field (E1)

Open

3.18

9.06

Treat. (T)

86.12

74.16

83.34

75.97

88.08

92.51

95.12

92.47

77.05

85.31

93.97

82.50

92.98

(E2)

Polyhouse

4.50

NS

E×T

85.26

74.30

82.04

78.19

88.06

92.12

93.59

87.90

76.43

85.61

92.57

80.29

92.10

Mean

seedlings

seedlings (cm) Open field

Survival percentage of

Relative elongation rate of

Table 2: Effect of pre-sowing treatments on seed vigour index, rela tive elongation rate and survival percentage of guava seedlings



Progressive Horticulture, Vol. 45, No. 1, March 2013 66

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tion time (35.42 days) of seeds was recorded in control (T12E2), whereas, in open field, the minimum mean germination time (26.28 days) of seeds was recorded in scraping of seed coat with sand paper (T3E1). The maximum mean germination time (38.32 days) of seeds was recorded in control (T12E1). Seeds sown in polyhouse recorded minimum mean germination time (29.34 days) than the seeds sown in open field (30.71 days). This was possibly due to injuring the hard seed coat by concentrated acid to accelerate the water absorption and to improve the gaseous exchange for hastening the process of germination (Nayak and Sen, 1999).




d) Seed vigour index The seed vigour index of the seedlings was significantly influenced by different pre-sowing treatments and interaction but the environment effect did not differ significantly (Table 2). In polyhouse, 10% hydrochloric acid for 2 minutes (T7E2) produced the maximum seed vigour index (226.68) of the seedlings at 45 days after sowing and it was found to be significantly superior over all other treatments. Significantly minimum seed vigour index (62.23) was recorded in control (T12E2), whereas, in open field, the seeds treated with 10% hydrochloric acid for 2 minutes (T7E1) recorded maximum seed vigour index (166.28) at 45 days after sowing while the minimum seed vigour index (44.49) was observed in control (T12E1). Seeds sown in polyhouse recorded maximum seed vigour index (141.57) while seed sown in open field recorded minimum seed vigour index (106.92). These results are in close conformity with the finding of Rahman and Quadir (1989) as they reported that acid treated seeds showed best performance in respect of seed germination and seed vigour index in guava. Similar result was reported in Aonla by Nayaka (2006) as he reported that acid scarified seeds gave maximum germination, took minimum number of days for 50 per cent germination and had very high seedling vigour index as compared to control.

e) Relative elongation rate The effect of different pre-sowing treatments and interaction on relative elongation rate of seedlings were found to be significant but the environment effect did not differ significantly (Table 2). Maximum relative elongation rate (0.098 cm) of seedlings in polyhouse was recorded in scraping of seed coat with sand paper + seeds soaked in GA3 100 ppm for 24 hours (T5E2) followed by scraping of seed coat with sand paper +


seeds soaked in GA3 50 ppm for 24 hours (T4E2) (0.093 cm). The minimum relative elongation rate (0.050 cm) of seedlings was recorded in control (T12E2) while in open field, the maximum relative elongation rate (0.082 cm) of seedlings was observed in scraping of seed coat with sand paper + seeds soaked in GA3, 50 ppm for 24 hours (T4E1) and minimum relative elongation rate (0.035 cm) of seedlings was recorded under control (T12E1). Seeds sown in polyhouse recorded maximum relative elongation rate (0.070 cm) of seedlings than open field condition (0.054 cm). These results are in conformity with the findings of Tendulkar (1978) and Pampanna and Sulikeri (2001) in sapota as they reported that GA3 application may be attributed to the cell multiplication and elongation in the cambium tissue.

f) Survival percentage of seedlings The data on survival percentage of seedlings (Table 2) revealed that various pre-sowing treatments and environment significantly affected the survival percentage of seedlings. However, the interaction were non significant. Among the pre-sowing treatments, the maximum survival percentage of seedlings (95.12%) at 60 days after sowing in polyhouse was recorded in the seeds treated with 10% hydrochloric acid for 2 minutes (T7E2) followed by (93.97%) in scraping of seed coat with sand paper (T3E2). The minimum survival percentage of seedlings (74.16%) was recorded in control (T12E2), whereas, in open field, the maximum survival percentage of seedlings (92.07%) at 60 days after sowing was recorded in the seeds treated with 10% hydrochloric acid for 2 minutes (T7E1) and the minimum survival percentage of seedlings (74.44%) was recorded in control (T12E1). Seeds sown in polyhouse gave maximum survival percentage of seedlings (86.12%) than the seeds sown in open field (84.41%). The probable cause of high survival percentage of seedlings might be due to early germination of seeds which helps in successful acclimatization of seedlings in field conditions and vigour of seedlings ultimately leads to better growth, thus, high survival. A similar observation has been reported by Shrivastava et al. (2002) in Aonla.

ACKNOWLEDGEMENTS Authors are grateful to Dr. K.K. Misra, Professor, Department of Horticulture, for his encouragement and helpful suggestions throughout the experimental period.


REFERENCES Anonymus, 2011. Indian Horticulture Database, National Horticulture Board, Gurgaon, Haryana, India. Chattopadhyay, P.K. and Dey, S.S. 1992. Note on standardisation of some aspects of Ber propagation. Indian J. Horti., 49(1): 47-49.



Nayaka, G. 2006. Propagation Studies in Aonla (Phyllanthus emblica L.), Thesis M.Sc. (Horticulture), University of Agricultural Science, Dharwad. Pampanna, Y. and Sulikeri, G.S. 2001. Effect of growth regulators on seed germination and seedling growth of Sapota. Karnataka J. Agri. Scie., 14: 1030-1036.

Denny, E.E. 1917. Permeability of membranes as related to their composition. Botanical Gazettee, 63: 468-485.

Rahman, M. and Quadir, M.A. 1989. Influence of different preconditioning treatments on the seed germination and seedling vigour of guava, jujube and Indian olive. Annual Agri. Res. Review, 39: 1821.

Doijode, S.D. 2001. Guava: Psidium guajava L. In: Doijode S.D. (ed) Seed Storage of Horticultural Crops. Haworth Press, New York, pp. 65–67.

Shrivastava, A.L.; Singh, H.K. and Singh, I.S. 2002. Studies on the propagation of Aonla (Emblica officinalis). Haryana J. Hort. Sci., 31(3-4): 156-158.

Hayes, W.B. 1953. Fruit Growing in India. Kitabistan, Allahabad, pp. 22-23.

Singh, S. and Soni, S.L. 1974. Effect of water and acid soaking periods on seed germination in guava. Punjab Hort. J., 14(3-4): 122-124.

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Nayak, G. and Sen, S.K. 1999. Effect of growth regulators, acid and mechanical scarification on germination of Bael (Aegle marmelos C.). Environment Ecolo., 17(3): 768-769.

Tendulkar, S.S.P. 1978. Studies on growth of rootstock and propagation of sapota (Manilkara achras (Mill) Fosberg). Thesis M.Sc. Ag. (Horticulture), University of Agricultural Sciences, Bangalore.

Received on 16 Feb., 2012 and accepted on 05 July, 2012