MadrasAgric.J.,2024; ; https://doi.org/10.29321/MAJ.10.500007

111|7-9|

RESEARCH ARTICLE

Received: 20 Aug 2024

Revised: 14 Sep 2024

Accepted: 21 Sep 2024

*Corresponding author's e-mail: ponarasan1999@gmail.com

Effect of Dates of Sowing and Nutrient Levels on Yield and

Yield Attributes of Sunn hemp (Crotalaria juncea)

Pon Arasan A^1*, Sanbagavalli S¹, Sakthivel N² and Vigneshwari R³

1Department of Agronomy, TNAU, Coimbatore - 641 003.

2Agricultural Research Station, Bhavanisagar - 638 451.

3Department of Seed Science and Technology, TNAU, Coimbatore - 641 003.

ABSTRACT

A field trial was done to determine the optimum sowing date and nutrient

levels on yield and yield parameters of Sunn hemp during summer (January

- May) 2022 at Eastern Block Farm, Tamil Nadu Agricultural University,

Coimbatore. The field trial was laid out with 12 treatments in a split-plot

design and every treatment was replicated thrice. Three sowing dates

(the last week of January, the first and second weeks of February) were

performed in the main plot, and four different nutrient levels (20:40:20 kg

NPK ha^-1, 25:50:25 kg NPK ha^-1, 30:60:30 kg NPK ha^-1 and 12.5 tons FYM

ha^-1) in the subplot. Yield attributes such as the number of pods per plant,

Seeds per pod, seed index, pod setting percentile, pod filling percentile, and

seed yield were noted. Sunn hemp sown during the second week of February

along with 30:60:30 kg NPK ha^-1was noted with higher yield attributes and

seed yield of Sunn hemp.

Keywords: Sunn hemp; Date of sowing; Nutrient level; Green manure; Seed production

1. INTRODUCTION

Sunn hemp (Crotalaria juncea) is one of the

important tropical legumes for its 3F activity (fertilizer,

fodder, and fiber) and is used as a cover crop (Eberle

and Shortnacy, 2021). It is contrarily called Indian

hemp, which originated from India. It belongs to the

family Fabaceae (Kavin et al., 2018).

India is the leading producer of Indian hemp which

is under an area of 10,300 ha with a production of

43600 bales and productivity of 715 kg ha^-1 followed

by Bangladesh and Brazil (IndiaStat, 2024). In India,

Sunn hemp was cultivated in the states of West Bengal,

Orissa, Chhattisgarh, Bihar, Rajasthan, Maharashtra,

Uttar Pradesh, and Madhya Pradesh (Pon Arasan et

al., 2022).

It provides 50-75:15-20:40-65 kg NPK ha^-1 through

green manure. Additionally, it fixes 50-60 kg N using

root nodules (Kavin et al., 2018). It improves water

holding capacity, and soil texture and neutralizes the

soil salinity. Apart from these, it performs as a cover

crop, checks soil erosion, and manages root-knot

nematode (Pon Arasan et al., 2022).

Under the sole cropping system, soil fertility is

reduced more rapidly. The increased cost of inorganic

fertilizers and poor soil fertility were the main reasons

for practicing green manuring activity (Sandhya Rani

et al., 2022). Sunn hemp cultivation area was reduced

from 1,64,900 ha (1970) to 11,000 ha (2021) in the

past five decades (IndiaStat, 2024). Non-availability

of good quality seeds is the major concern in area

reduction under Sunn hemp cultivation. Improper

agronomic practices led to poor Sunn hemp seed

production. There is a need to optimize the agronomic

practices i.e. sowing time, nutrient management, weed

management, spacing, and irrigation management.

Considering this, the field trial was carried out to find

the optimum sowing date and nutrient level for higher

seed yield of Sunn hemp.

2. MATERIAL AND METHODS

2.1. Experimental site and soil analysis

The field trial was conducted during the Summer

of 2022 at Eastern Block Farm,

MadrasAgric.J.,2024; ; https://doi.org/10.29321/MAJ.10.500007

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Department of Agronomy, Tamil Nadu Agricultural

University (TNAU), Coimbatore. The research field was

sited at 11˚1’6” N latitude and 76˚58’21” E longitude

with an elevation of 426.7 m above MSL in the Western

zone of Tamil Nadu. The field was sandy clay loam

with pH and electrical conductivity of 8.91 and

0.28 dSm^-1, respectively. The initial available

nutrient content of the soil was 179 N kg ha^-1(Low),

27.2 P2O5 kg ha^-1 (High), and 806 kg K

ha^-1

(High). The organic carbon content of the soil was

0.49%.

2.2. Experiment details

The experimental design was laid out in a split-

plot design with three main plots and four subplots

and replicated thrice. Several sowing dates were

considered as the main plot and nutrient levels

in subplots. Main plot treatments are D1 - sowing

during January 4^th week, D2 - sowing during February

1^st week, D3 - sowing during February 2^nd week and

subplot treatments are N1 - 20:40:20 kg NPK ha^-1, N2 -

25:50:25 kg NPK ha^-1, N3 - 30:60:30 kg NPK ha^-1 and

N4 - 12.5 tons of FYM ha^-1.

2.3. Weather conditions prevailed during the

cropping period

During the entire field experiment, an average

maximum and minimum temperature of 36.3˚C and

24.4 ˚C with an average wind speed of 5.1 km hr^-1

prevailed. The total amount of rainfall received over

the cropping period was 57.9 mm.

2.4. Agronomic practices

Local landrace seed was obtained from the

Central Farm of TNAU for this study. After primary and

secondary tillage, ridges and furrows were formed at

60 cm intervals. Seeds were sown on both sides of the

ridges at 30 x 10 cm spacing. The crop was raised fully

under irrigated conditions. Based on the treatments,

the entire amount of farmyard manure (FYM),

phosphorous (P), and potassium (K) were applied

as basal dose, whereas nitrogen (N) was applied in

three doses (50% N as basal, 25% N at 30 DAS and

25% N at 60 DAS). Urea, single super phosphate, and

muriate of potash were used as sources of N, P, and

K, respectively. All the crop production practices were

followed as per the recommendations of the TNAU

Crop Production Guide - Agriculture, 2020.

2.5. Biometric observation and statistical

analysis

In the net-plot area, randomly five plants were

selected and tagged to record observations, and data

were collected. A total number of pods were counted

and averaged from five tagged plants. Total seeds were

counted from twenty pods and averaged into number

of seeds capsule^-1. Pod filling percentage (Eqn. 1)

was worked out with the number of seeds and scars

presented in a single pod.

(Eqn. 1)

Pod setting percentage (Eqn. 2) worked out with

the total number of pods to the number of flowers in

five tagged plants.

(Eqn. 2)

After threshing and cleaning, seeds from the net

plot were weighed and given as seed yield. A hundred

seeds were counted and weighed as seed index. Stalk

yield was computed by weighing the leftover stalks

after the threshing of pods. The data of different

parameters were statistically analysed by the ANOVA

method suggested by Gomez and Gomez (2010).

3. RESULTS AND DISCUSSION

3.1. Number of pods plant^-1

The effect of dates of sowing and nutrient levels

on the number of pods plant^-1 is listed in Table 1.

Sunn hemp sown in the last week of January recorded

significantly a greater number of pods plant^-1 (18.7).

February first week sown crop has recorded the

smaller number of pods plant^-1 (14.5). A reduction

of 22.5 percent of pods was recorded in February’s

first week sown crop over January’s last week sown

Sunn hemp. Excessive rain with heavy wind during

the flowering stage of February’s first week sown crop

attributed lower number of pods plant^-1. An increase in

cumulative heat units (CHU) has negatively correlated

with the number of pods in Sunn hemp (Figure 1).

Higher growing degree day accumulation is negatively

correlated with yield attributes of Sunn hemp

(Subrahmaniyan et al., 2021). Early sown crops had

enough duration for growth and development (Ahmad

et al., 2021).

Application of nutrients @ 30:60:30 kg NPK ha^-1

recorded a higher number of pods plant^-1 (18.5) than

MadrasAgric.J.,2024; ; https://doi.org/10.29321/MAJ.10.500007

111|7-9|

12.5 t FYM ha^-1 (14.8) applied plot. Application of

high levels of nutrients led to greater absorption and

translocation of nutrients, which may produce more

pods plant^-1 (Kavin et al., 2018). Sarika et al., (2022)

confirmed similar findings in soybean.

Sunn hemp sown during January last week along

with 25:50:25 kg NPK ha^-1 produced a greater number

of pods plant^-1 (21.0), which is on par (20.2) with

January last week’s sown crop with the nutrient level

of 30:60:30 kg NPK ha^-1.

3.2. Seeds pod^-1

The effect of dates of sowing and nutrient levels on

the number of seeds pod^-1 is listed in Table 1. January

Last week’s sown crop resulted in a greater seeds pod^-1

(10.15), which was on par (9.26) with the crop sown in

the first week of February. Crop sown during the second

week of February registered fewer seeds pod^-1 (8.94).

Cumulative heat units had a negative correlation with

the number of seeds pod^-1. A similar result was noticed

by Kavin et al. (2018). Earlier sowing date has enough

time for seed filling, which may result in more seeds

pod^-1. Different nutrient levels were unaffected the

number of seeds pod^-1.

3.3. Seed Index

The effect of dates of sowing and nutrient levels on

seed index is listed in Table 1. The seed index of Sunn

hemp was statistically non-significant among different

dates of sowing, nutrient level, and interaction effect.

3.4. Pod setting percentage

The effect of dates of sowing and nutrient levels

on pod setting percentage is listed in Table 2. Sunn

hemp sown during the last week of January registered

with more pod setting percentage (40.61 %). Crop

sown during the second week of February was noticed

with a lower pod setting percentage (29.75 %). Higher

cumulative heat units during February’s second

week may reduce pod setting percentage (Figure 1).

Cumulative heat unit has a negative correlation with

yield attributes of Sunn hemp (Subrahmaniayan et al.,

2021).

Application of 20:40:20 kg NPK ha^-1 recorded a

higher pod setting percentage (37.24 %). However,

it was on par with 25:50:25 kg NPK ha^-1. Supply of

30:60:30 kg NPK ha^-1 registered with a lower (32.94

%) pod setting percentage. Application of nitrogenous

fertilizers during the flowering stage may result in more

flower dropping. A similar outcome was confirmed by

Chakma et al. (2020) in soybean.

January last week sown crop coupled with

20:40:20 kg NPK ha^-1 registered a higher pod setting

percentage (43.96 %). It was statistically on par with

sowing during January’s fourth week with nutrient

levels of 25:50:25 (41.01 %) and 30:60:30 kg NPK

ha^-1 (41.63 %). February second week sown crop along

with 30:60:30 kg NPK ha^-1 recorded a lower (26.44 %)

pod setting percentage.

3.5. Pod filling percentage

The effect of dates of sowing and nutrient

levels on pod filling percentage is listed in Table 2.

January last week’s sown Sunn hemp registered a

higher pod filling percentage (65.31 %), which was

on par (61.15 %) with February’s first week sown

crop. A lower pod filling percentage (58.12 %) was

attributed to February’s second week sown crop. Pod

filling percentage is negatively correlated with CHU

(Figure 1). The increased temperature during

February’s second week sown crop may result in higher

GDD and poor filling percentage (Subrahmaniyan et

al., 2021)

3.6. Seed yield

The effect of dates of sowing and nutrient levels

on seed yield is listed in Table 3. Sunn hemp sown

during the last week of January registered with higher

seed yield (1380 kg ha^-1) than February’s first week

sown crop (936 kg ha^-1). January fourth week sown

crop recorded a 32.2% yield increase over February

first week sown crop. The seed yield of Sunn hemp was

positively correlated with relative thermal disparity

(Figure 2). Yield reduction in late-sown crops may

attributed to high temperatures prevailing during

crop growth and resulting in reduced accumulation of

photosynthates (Taruna et al., 2013). Increased yield

attributes in earlier sowing dates may produce higher

seed yield (Banerjee et al., 2021).

Application of nutrients @ 30:60:30 kg NPK ha^-1

produced higher seed yield (1352 kg ha^-1). Lower seed

yield (910 kg ha^-1) was attributed to the nutrient level

of 12.5 t FYM ha^-1. Higher accessibility of nutrients

with higher doses of fertilizer led to better absorption

and translocation of nutrients which may produce

increased seed yield (Sanggonda and Eshanna, 2018;

Sarika et al., 2022)

MadrasAgric.J.,2024; https://doi.org/10.29321/MAJ.10.500007

Table 1. Effect of dates of sowing and nutrient levels on yield parameters of Sunn hemp

Treatments

Number of pods plant^-1

Number of seeds pod^-1

Seed Index

Mean

18.7

21.0

20.2

14.9

18.7

9.82

10.12

10.83

9.83

10.15

2.36

2.24

2.43

2.35

2.34

13.5

14.9

16.8

12.8

14.5

9.22

9.37

9.60

8.87

9.26

2.08

2.23

2.30

2.06

2.17

13.3

15.6

18.5

16.7

16.0

8.62

9.22

9.30

8.62

8.94

2.01

2.15

2.19

1.99

2.09

Mean

15.2

17.2

18.5

14.8

9.22

9.57

9.91

9.10

2.15

2.21

2.31

2.13

D x N

N x D

D x N

N x D

D x N

N x D

SED

0.55

0.77

1.08

0.34

0.37

0.65

0.64

0.07

0.08

0.15

CD (0.05)

1.29

1.64

2.11

0.94

(D1 - sowing during January 4^th week; D2 - sowing during February 1^st week; D3 - sowing during February 2^nd week; N1 - 20:40:20 kg NPK ha^-1;

N2 - 25:50:25 kg NPK ha^-1; N3 - 30:60:30 kg NPK ha^-1 and N4 - 12.5 tons of FYM ha^-1)

Table 2. Effect of dates of sowing and nutrient levels on pod setting and filling percentage of Sunn hemp

Treatments

Pod setting percentage

Pod filling percentage

Mean

43.97

41.01

41.63

35.85

40.61

62.32

67.61

69.86

61.45

65.31

38.67

35.39

30.75

29.94

33.69

60.64

60.56

63.61

59.81

61.15

29.09

27.78

26.44

35.69

29.75

57.77

57.99

61.55

55.16

58.12

Mean

37.24

34.73

32.94

33.83

60.24

62.05

65.01

58.80

D x N

N x D

D x N

N x D

SED

1.38

1.22

2.28

2.11

1.87

2.27

3.88

3.93

CD (0.05)

3.82

2.55

5.36

4.42

5.20

(D1 - sowing during January 4^th week; D2 - sowing during February 1^st week; D3 - sowing during February 2^nd week; N1 - 20:40:20 kg NPK ha^-1;

N2 - 25:50:25 kg NPK ha^-1; N3 - 30:60:30 kg NPK ha^-1 and N4 - 12.5 tons of FYM ha^-1)

MadrasAgric.J.,2024; ; https://doi.org/10.29321/MAJ.10.500007

111|7-9|

Madras Agric.J.,2024; htttps://doi.org/10.29321/MAJ.10.500007

Volume 111| Issue 7-9| 1

Figure 1. Effect of cumulative heat unitts (CHU) on yield attribbutes of Sunn hemp

Figure 2. Effect of relative thermal disparity (RTD) on yieeld attributes of Sunn hemp

Volume 111| Issue 7-9

Figure 2. Effect of relative thermal disparity (RTD) on yield attributes of Sunn hemp

Figure 1. Effect of cumulative heat units (CHU)

on yield attributes of Sunn hemp

Figure 2. Effect of relative thermal disparity

(RTD) on yield attributes of Sunn hemp

Table 3. Effect of dates of sowing and nutrient levels on yield of Sunn hemp

Treatments

Seed yield

Stalk yield

Mean

1322

1470

1657

1071

1380

20.40

21.25

21.65

15.40

19.68

825

985

1190

742

936

27.87

28.00

29.41

24.13

27.35

732

985

1209

917

961

26.94

32.02

35.12

30.86

31.24

Mean

960

1147

1352

910

25.07

27.09

28.73

23.46

D x N

N x D

D x N

N x D

SED

35.6

28.7

55.9

49.7

1.18

0.88

1.77

1.53

CD (0.05)

98.9

60.3

132.7

104.4

3.28

1.85

4.26

3.21

(D1 - sowing during January 4^th week; D2 - sowing during February 1^st week; D3 - sowing during February 2^nd

week; N1 - 20:40:20 kg NPK ha^-1; N2 - 25:50:25 kg NPK ha^-1; N3 - 30:60:30 kg NPK ha^-1 and N4 - 12.5 tons of

FYM ha^-1)

Sunn hemp sown during the last week of January

coupled with nutrient level of 30:60:30 kg NPK ha^-1

produced a higher seed yield (1657 kg ha^-1) than

February second week sown crop with a nutrient level

of 20:40:20 kg NPK ha^-1 (732 kg ha^-1). Higher yield

attributes recorded with January last week’s sown

crop and 30:60:30 kg NPK ha^-1 applied plot may result

in higher seed yield.

3.7. Stalk yield

The effect of dates of sowing and nutrient levels

on stalk yield is listed in Table 3. Sunn hemp sown

during February’s second week was recorded with

increased stalk yield (31.24 q ha^-1). Last week of

January sown Sunn hemp recorded lower stalk yield

(19.68 q ha^-1). Increased GDD accumulation over

late sowing may result in higher stalk yield, which

has a highly positive correlation (Figure 1). Increased

GDD accumulation positively correlated with DMP

(Subrahmaniyan et al., 2021).

Supply of nutrients at the nutrient level of 30:60:30

kg ha^-1 registered higher stalk yield (28.73 q ha^-1)

which was statistically similar to the nutrient level of

25:50:25 kg NPK ha^-1 (27.09 q ha^-1). Application of FYM

@ 12.5 t ha^-1 obtained a lower stalk yield(23.46 q ha^-1).

Application of higher levels of nutrients may result in

increased stalk yield due to effective translocation of

nutrients (Sarika et al., 2022).

Sunn hemp sown during February’s second week

with 30:60:30 kg NPK ha^-1 produced a higher stalk

yield (35.12 q ha^-1) than Sunn hemp

MadrasAgric.J.,2024; ; https://doi.org/10.29321/MAJ.10.500007

111|7-9|

sown during the last week of January with 12.5 t FYM

ha^-1 applied plot (15.04 q ha^-1).

4. CONCLUSION

From the above results, it is concluded that the

sowing of Sunn hemp during the last week of February

with the nutrient level of 30:60:30 kg NPK ha^-1 has

produced better yield and yield attributes in the

Coimbatore region of Tamil Nadu.

Funding and Acknowledgment

The authors acknowledge the financial support

for the experiment is provided by the Department

of Agronomy, Tamil Nadu Agricultural University,

Coimbatore.

Ethics statement

No specific permits were required for the described

field studies because no human or animal subjects

were involved in this research.

Originality and plagiarism

This research article was written by our own with

original research works carried out by us.

Consent for publication

All the authors agreed to publish the content.

Competing interests

There were no conflicts of interest in the publication

of this content

Data availability

All the data of this manuscript are included in the

MS. No separate external data source is required. If

anything is required from the MS, certainly, this will be

extended by communicating with the corresponding

author through the corresponding official mail;

ponarasan1999@gmail.com

Author contributions

Research grant - S. Sanbagavalli

Idea conceptualization - N. Sakthivel

Experiments - A. Pon Arasan

Guidance

Sanbagavalli,

Sakthivel,

R.Vigneshwari

Writing original draft - A. Pon Arasan

Writing-reviewing & editing - S. Sanbagavalli,

N. Sakthivel, R. Vigneshwari, A. Pon Arasan

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