3.1 Emergence Uniformity (EU)
The results showed that the effect of planting date on Emergence uniformity (EU) was significant at 5% level of probability while planting depth and the interaction of factors had a significant effect on EU at 1% level of probability (Table 1). The mean comparisons of the interaction of factors showed that EU was higher in all the depths of the first planting date than the second planting date. The EU was reduced by increasing the planting depth in both planting dates so that the maximum EU was observed in the first planting date in November at the planting depth of 1 cm while the minimum EU occurred in the second planting date at 14cm planting depth (Table 2). In this regard, Biabani et al. (13) reported that the EU of lentil seeds decreased by increasing the planting depth so that the minimum EU emerged at the 14-cm depth. Moreover, Biabani et al. (13) indicated that the planting depth greater than 7cm (from 7 to 12.5) had a negative effect on all emergence properties of lentil seeds. Gopal (15) and Johnson et al. (16) showed that appropriate planting depth led to germination uniformity and emergence of the majority of seeds, which was consistent with findings of the present study.
Table 1, Analysis of variance of the effects of date and depth of planting on plant emergence and seedling traits in lentil.
|
|
Source of variation
|
df
|
|
MS
|
|
|
EU
|
D05
|
D10
|
D50
|
D90
|
D95
|
|
R
|
2
|
3.99ns
|
4.46ns
|
2.46ns
|
4.29ns
|
0.21ns
|
0.12ns
|
|
Date of planting (A)
|
1
|
125.95*
|
779.57**
|
782.75**
|
732.28**
|
433.23**
|
305.96**
|
|
Error
|
2
|
4.24
|
3.46
|
5.25
|
1.34
|
2.20
|
1.26
|
|
Depth of planting(B)
|
14
|
28.66**
|
210.26**
|
222.62**
|
254.84**
|
305.99**
|
322.17**
|
|
A*B
|
14
|
27.90*
|
5.09**
|
5.78**
|
4.94**
|
5.63**
|
3.35**
|
|
Error
|
56
|
1.20
|
0.38
|
0.60
|
0.78
|
1.99
|
0.97
|
|
C. V (%)
|
-
|
15.16
|
0.22
|
3.91
|
3.97
|
5.74
|
3.88
|
|
|
|
**,* : significant at p ≤ 0.01 and p ≤ 0.05, respectively.
|
|
|
![](https://myfiles.space/user_files/122228_c8a1650c59388082/122228_custom_files/img1691763333.png)
|
Table 2, Effects of date and depth of planting on emergence and seedling traits in lentil
|
|
Date of sowing*
|
Depth of sowing*(cm)
|
EU
|
D05 (day)
|
D10 (day)
|
D50 (day)
|
D90 (day)
|
D95 (day)
|
1
|
0
|
0.00
|
0.00
|
0.00
|
0.00
|
0,00
|
0.00
|
1
|
1
|
14.94
|
14.22
|
14.38
|
16.05
|
18.55
|
20.71
|
1
|
2
|
11.29
|
14.25
|
14.42
|
16.42
|
18.81
|
21.38
|
1
|
3
|
9.67
|
14.61
|
14.90
|
18.45
|
21.28
|
21.83
|
1
|
4
|
9.41
|
14.89
|
15.22
|
19.19
|
21.58
|
23.16
|
1
|
5
|
9.42
|
15.42
|
16.60
|
20.48
|
24.22
|
24.48
|
1
|
6
|
9.40
|
15.48
|
16.90
|
20.91
|
25.09
|
24.99
|
1
|
7
|
9.37
|
15.70
|
18.50
|
21.27
|
25.12
|
26.23
|
1
|
8
|
9.22
|
15.89
|
20.15
|
21.68
|
25.08
|
26.38
|
1
|
9
|
9.07
|
19.22
|
20.31
|
22.13
|
25.42
|
26.68
|
1
|
10
|
7.64
|
19.54
|
20.31
|
22.60
|
25.57
|
26.94
|
1
|
11
|
7.70
|
19.64
|
20.37
|
22.77
|
25.68
|
27.21
|
1
|
12
|
6.59
|
20.27
|
19.96
|
22.78
|
25.98
|
27.39
|
1
|
13
|
6.39
|
20.87
|
20.73
|
22.98
|
26.48
|
28.00
|
1
|
14
|
6.37
|
21.89
|
20.88
|
23.30
|
26.85
|
28.49
|
2
|
0
|
0.00
|
0.00
|
0.00
|
0.00
|
0.00
|
0.00
|
2
|
1
|
11.00
|
18.73
|
19.80
|
23.48
|
26.34
|
27.01
|
2
|
2
|
10.05
|
19.87
|
20.89
|
24.20
|
26.17
|
27.17
|
2
|
3
|
8.76
|
20.47
|
21.65
|
24.82
|
26.53
|
27.37
|
2
|
4
|
8.31
|
21.31
|
22.10
|
25.64
|
27.01
|
27.35
|
2
|
5
|
74..61
|
22.36
|
22.22
|
25.74
|
27.19
|
27.84
|
2
|
6
|
7.04
|
22.48
|
23.17
|
25.40
|
27.34
|
28.38
|
2
|
7
|
6.93
|
23.31
|
23.76
|
26.21
|
27.95
|
28.97
|
2
|
8
|
6.10
|
23.88
|
24.39
|
27.25
|
28.69
|
29.00
|
2
|
9
|
5.66
|
24.69
|
25.57
|
27.76
|
29.63
|
30.15
|
2
|
10
|
5.39
|
25.25
|
26.03
|
28.63
|
30.35
|
30.76
|
2
|
11
|
4.53
|
26.06
|
27.65
|
28.83
|
30.52
|
30.84
|
2
|
12
|
3.80
|
26.46
|
27.18
|
28.61
|
31.11
|
31.24
|
2
|
13
|
3.00
|
27.09
|
28.46
|
29.91
|
31.30
|
31.51
|
2
|
14
|
2.25
|
28.22
|
29.23
|
30.11
|
31.39
|
31.60
|
LSD (0.05)
|
-
|
1.79
|
1.00
|
1.27
|
1.45
|
2.31
|
1.61
|
|
* 1 and 2 mean for date of planting and similarly what the numbers 1–14 mean for depth of sowing.
|
|
3.2 Time to 5% of Emergence (D05)
The interaction of treatments was significant on the time to 5% emergence (Table 1). The mean comparison of the interaction of factors showed that the first planting date in November had a shorter time to 5% of emergence than the winter planting date and was also evident at all planting depths. In general, all the shallow depths of planting (except for surface spray) had a shorter time to emergence. Meanwhile, the minimum time to 5% emergence was observed in the first planting date in November at planting depths of 1 and 2cm while the maximum time to 5% emergence was observed for the 14cm planting depth in the second planting date (Table 2).
3.3 Time to 10, 50, 90 and 95% Emergence (D10, D50, D90 & D95)
All factors had a significant effect on D10, D50, D90 and D95 at 1% level of probability (Table 1). The mean comparison of the interaction of factors showed that all the treatments of planting depth had a shorter time to 10, 50, 90 and 95% emergence in the first planting date in November than the same planting depths in the second planting date in December. Accordingly, the minimum time to emergence was observed in the first planting date in November at the planting depths of 1 to 4cm while the maximum time to emergence was obtained from the second planting date at the planting depths of 11 to 14 cm (Table 2).
Warm and humid weather led to shorter time to emergence in the first planting date in November. Early and rapid emergence would benefit crop production by avoiding high temperature and drought stresses during critical podding, flowering and seed setting periods and promote improved crop yields. This point was confirmed by Marvi (9), Turk et al. (10) and Varshnery (11). The emergence time (D05 to D95) was delayed by increasing the planting depths especially in the second planting date so that the fastest emergence time was observed at the shallow planting depths (1-6cm) while the slowest germination time was perceived at the great depths (10-14cm). These findings were in line with the results of Biabani et al. (2015) who showed that the emergence time (D05 to D95) was delayed by increasing planting depths so that this delay lasted 10 days at the planting depths of 13 and 14cm. Yousefi Daz et al. (22) indicated that amongst the planting depths of 3, 6, 9 and 12cm, the 12cm planting depth had the maximum time to 5, 10, 50, 90 and 95% emergence while the 3cm planting depth had the minimum time to 5, 10, 50, 90 and 95 percent of emergence.
3.4 Percentage of Emergence
The interaction of planting date and depth had a significant effect on percentage of emergence at 1% confidence level (Table 3). The mean comparison of the interaction of factors showed that the percentage of emergence was higher at shallower planting depths (except for zero) in both planting dates. However, it is worth noting that all the treatments of planting depths had a higher percentage of emergence in the first planting date in November than the same treatments in the second planting date in December so that the maximum percentage of emergence was observed at the planting depths of 1 and 2cm in the first planting date in November while the minimum percentage of emergence occurred at planting depths of 12, 13 and 14cm in the second planting date (Table 4).
Table 3
Effects of date and depth of planting on seedling traits in lentil
Date of seeding*
|
Depth of Seeding*(cm)
|
Percentage of emergence
|
Rate of emergence
|
Seed vigor
|
Number of branches
|
seedling Dry weight (mg)
|
Leaf area (cm2)
|
1
|
0
|
0.00
|
0.00
|
0.00
|
0.00
|
0.00
|
0.00
|
1
|
1
|
92.59
|
1.95
|
135.1
|
2.77
|
225.6
|
21.92
|
1
|
2
|
92.59
|
2.16
|
145.2
|
2.80
|
237.8
|
26.44
|
1
|
3
|
90.13
|
1.64
|
133.8
|
2.80
|
214.4
|
20.61
|
1
|
4
|
81.48
|
1.33
|
120.4
|
2.47
|
208.9
|
22.09
|
1
|
5
|
76.54
|
1.00
|
95.36
|
2.26
|
172.4
|
20.18
|
1
|
6
|
72.84
|
1.04
|
100.1
|
1.93
|
190.1
|
20.13
|
1
|
7
|
71.60
|
0.92
|
100.5
|
1.93
|
182.2
|
16.40
|
1
|
8
|
54.32
|
0.63
|
63.59
|
1.67
|
138.2
|
14.10
|
1
|
9
|
51.85
|
0.60
|
60.62
|
1.40
|
124.4
|
12.74
|
1
|
10
|
44.44
|
0.50
|
50.53
|
1.46
|
129.4
|
12.19
|
1
|
11
|
55.70
|
0.61
|
70.51
|
1.45
|
116.7
|
10.64
|
1
|
12
|
45.68
|
0.50
|
65.58
|
1.48
|
116.7
|
10.44
|
1
|
13
|
36.14
|
0.40
|
46.94
|
1.20
|
105.0
|
9.12
|
1
|
14
|
32.10
|
0.36
|
40.76
|
1.13
|
79.79
|
8.36
|
2
|
0
|
0.00
|
0.00
|
0.00
|
0.00
|
0.00
|
0.00
|
2
|
1
|
62.07
|
0.70
|
70.51
|
1.93
|
147.8
|
17.13
|
2
|
2
|
79.31
|
0.85
|
101.2
|
1.95
|
148.9
|
19.61
|
2
|
3
|
86.21
|
0.92
|
108.7
|
2.00
|
175.5
|
21.20
|
2
|
4
|
68.97
|
0.76
|
86.12
|
1.61
|
143.3
|
15.43
|
2
|
5
|
69.41
|
0.82
|
90.47
|
1.60
|
140.0
|
14.23
|
2
|
6
|
64.33
|
0.73
|
72.11
|
1.26
|
136.9
|
14.56
|
2
|
7
|
60.58
|
0.65
|
71.36
|
1.53
|
135.6
|
13.85
|
2
|
8
|
39.53
|
0.45
|
44.26
|
1.40
|
117.8
|
11.82
|
2
|
9
|
37.34
|
0.43
|
42.80
|
1.27
|
95.55
|
10.41
|
2
|
10
|
34.89
|
0.36
|
35.01
|
1.20
|
91.11
|
8.40
|
2
|
11
|
27.00
|
0.32
|
27.82
|
1.10
|
76.11
|
8.72
|
2
|
12
|
26.48
|
0.28
|
29.07
|
1.00
|
75.39
|
6.93
|
2
|
13
|
18.95
|
0.28
|
18.34
|
0.80
|
61.00
|
6.60
|
2
|
14
|
15.62
|
0.23
|
17.48
|
0.53
|
58.00
|
6.07
|
LSD (0.05)
|
|
8.09
|
0.146
|
8.72
|
0.43
|
12.84
|
3.06
|
* 1 and 2 mean for date of planting and similarly what the numbers 1–14 mean for depth of sowing. |
The findings of the present study were consistent with the results of Hwang et al. (17) who showed that shallow depths and timely planting dates increased the percentage of emergence of Colza. Moreover, the present results were in line with the findings Mounim and Mirtaheri (18) who indicated that the percentage of emergence of lentil seeds was greater at shallower depths than deeper planting depths. Siddique and loss (19) reported that the planting depth of 2.5-5 cm increased the seedling establishment of pea, bean and lentil. The results of the present study were similar to findings of Hwang et al. (17), Mounim and Mirtaheri (18) and Siddique and loss (19). Likewise, Biabani et al. (13) stated that the percentage of germination was greatly influenced by the planting depth so that the percentage of germination decreased by almost 50% by increasing the planting depth from 7 to 14cm.
Table 3
, Analysis of variance of the effects of date and depth of planting on plant emergence and seedling traits in lentil.
Source of variation
|
|
|
|
MS
|
|
df
|
emergence%
|
Rate of emergence
|
Seed vigor
|
Number of branches
|
Seedling dry weight
|
Leaf area
|
R
|
2
|
432.6ns
|
0.01ns
|
94.67ns
|
0.09ns
|
157.48ns
|
61.10*
|
Date of planting(A)
|
1
|
4297.9**
|
3.43**
|
17114**
|
5.78**
|
40821**
|
253.44**
|
Error
|
2
|
25.37
|
0.09
|
36.48
|
0.16
|
67.64
|
4.93
|
Depth of planting(B)
|
14
|
3950.5**
|
1.13**
|
8090.2**
|
2.34**
|
18032**
|
233.42**
|
A*B
|
14
|
107.17**
|
0.25**
|
386.16**
|
0.32**
|
760.44**
|
8.17*
|
Error
|
56
|
24.51
|
0.01
|
28.44
|
0.07
|
61.58
|
3.49
|
C. V (%)
|
-
|
9.35
|
12.41
|
7.83
|
17.07
|
6.12
|
14
|
|
|
**,* : significant at p ≤ 0.01 and p ≤ 0.05, respectively.
|
|
|
Table 4, Effects of date and depth of planting on seedling traits in lentil
|
|
Date of sowing*
|
Depth of sowing*(cm)
|
Percentage of emergence
|
Rate of emergence
|
Seed vigor
|
Number of branches
|
seedling Dry weight (mg)
|
Leaf area (cm2)
|
1
|
0
|
0.00
|
0.00
|
0.00
|
0.00
|
0.00
|
0.00
|
1
|
1
|
92.59
|
1.95
|
135.1
|
2.77
|
225.6
|
21.92
|
1
|
2
|
92.59
|
2.16
|
145.2
|
2.80
|
237.8
|
26.44
|
1
|
3
|
90.13
|
1.64
|
133.8
|
2.80
|
214.4
|
20.61
|
1
|
4
|
81.48
|
1.33
|
120.4
|
2.47
|
208.9
|
22.09
|
1
|
5
|
76.54
|
1.00
|
95.36
|
2.26
|
172.4
|
20.18
|
1
|
6
|
72.84
|
1.04
|
100.1
|
1.93
|
190.1
|
20.13
|
1
|
7
|
71.60
|
0.92
|
100.5
|
1.93
|
182.2
|
16.40
|
1
|
8
|
54.32
|
0.63
|
63.59
|
1.67
|
138.2
|
14.10
|
1
|
9
|
51.85
|
0.60
|
60.62
|
1.40
|
124.4
|
12.74
|
1
|
10
|
44.44
|
0.50
|
50.53
|
1.46
|
129.4
|
12.19
|
1
|
11
|
55.70
|
0.61
|
70.51
|
1.45
|
116.7
|
10.64
|
1
|
12
|
45.68
|
0.50
|
65.58
|
1.48
|
116.7
|
10.44
|
1
|
13
|
36.14
|
0.40
|
46.94
|
1.20
|
105.0
|
9.12
|
1
|
14
|
32.10
|
0.36
|
40.76
|
1.13
|
79.79
|
8.36
|
2
|
0
|
0.00
|
0.00
|
0.00
|
0.00
|
0.00
|
0.00
|
2
|
1
|
62.07
|
0.70
|
70.51
|
1.93
|
147.8
|
17.13
|
2
|
2
|
79.31
|
0.85
|
101.2
|
1.95
|
148.9
|
19.61
|
2
|
3
|
86.21
|
0.92
|
108.7
|
2.00
|
175.5
|
21.20
|
2
|
4
|
68.97
|
0.76
|
86.12
|
1.61
|
143.3
|
15.43
|
2
|
5
|
69.41
|
0.82
|
90.47
|
1.60
|
140.0
|
14.23
|
2
|
6
|
64.33
|
0.73
|
72.11
|
1.26
|
136.9
|
14.56
|
2
|
7
|
60.58
|
0.65
|
71.36
|
1.53
|
135.6
|
13.85
|
2
|
8
|
39.53
|
0.45
|
44.26
|
1.40
|
117.8
|
11.82
|
2
|
9
|
37.34
|
0.43
|
42.80
|
1.27
|
95.55
|
10.41
|
2
|
10
|
34.89
|
0.36
|
35.01
|
1.20
|
91.11
|
8.40
|
2
|
11
|
27.00
|
0.32
|
27.82
|
1.10
|
76.11
|
8.72
|
2
|
12
|
26.48
|
0.28
|
29.07
|
1.00
|
75.39
|
6.93
|
2
|
13
|
18.95
|
0.28
|
18.34
|
0.80
|
61.00
|
6.60
|
2
|
14
|
15.62
|
0.23
|
17.48
|
0.53
|
58.00
|
6.07
|
LSD (0.05)
|
-
|
8.09
|
0.146
|
8.72
|
0.43
|
12.84
|
3.06
|
|
* 1 and 2 mean for date of planting and similarly what the numbers 1–14 mean for depth of sowing.
|
|
3.5 Rate of Emergence
The simple interaction of planting date and planting depth had a significant effect on rate of emergence at the 1% confidence level (Table 3). The mean comparison of the interaction of factors showed that the maximum emergence was observed at the planting depth of 2cm in the first planting date in November without any significant difference from the 1cm planting depth at the same planting date. The minimum emergence was observed at the 14cm planting depth in the second planting date (Table 4). The results of the present study showed that planting date and planting depth should be adjusted in order to achieve optimum emergence. That is, the planting date should be considered earlier than generally practiced due to the lack of appropriate machines for planting at 5cm depth and absence of limitations due to environmental restrictions and climate conditions. If early planting dates are not possible due to environmental restrictions, shallower planting depths should be intended in accordance with the crop type and end-season environmental conditions (in case of temperature stress and drought stress, the planting depth should be deeper) so as to neutralize the reduction of rate of germination caused by planting date by decreasing the time to germination and increasing establishment at the right time. Cultivation of lentil at the right time allows the plant to be established properly and completes the plant’s life cycle before the onset of growth limiting temperatures. In general, planting date is determinant of flowering date. It also has great impact on dry matter accumulation, number of seeds and grain yield, which confirmed the findings of Marvi (9), Turk et al. (10) and Varshnery (11). Early planting allows the germination, seedling establishment and growth during favorable temperature and relative humidity conditions and despite higher radiation energy and produces stronger plants and more dry matter. Determining the appropriate planting time leads to early, rapid, uniform and complete seed germination. This, in turn, leads to faster soil coverage, more solar radiation receipt, further leaf growth and development, higher crop growth rate and more photosynthesis accumulation (12). The findings of the present study were consistent with the results of Hwang et al. (17) who showed that shallow depths and timely planting dates increased the rate of germination of Colza. Moreover, the present results were in line with the findings Mounim and Mirtaheri (18) and Biabani et al. (13) who indicated that the rate of germination of lentil seeds was higher in shallower depths than greater planting depths.
3.6 Seeds Vigor
As displayed in Table (3), the interaction of planting date and depth had a significant effect on seed vigor at 1% confidence level. The mean comparison of the interaction of factors showed that the seed vigor was higher at shallower planting depths than at deeper depths in both the first planting date in November and the winter planting date. In general, the maximum seed vigor was observed at the planting depth of 2cm in the first planting date in November while the minimum seed vigor was witnessed at the 14-cm planting depth in the winter planting date (Table 4). These results indicated that the percentage of germination and stem length were higher in shallower planting depths than at deeper depths. Also, the seedling establishment was better at shallower depths than deeper depths in both planting dates. In this regard, researchers have shown that planting deep decreased the seed vigor of lentil; however, seed priming with salicylic acid and distilled water improved the seed vigor in comparison to the control treatment of planting depth (13). Other researchers have reported that if the seed is planted at shallower depths, it will dry and cannot germinate. On the contrary, if the seed is planted at greater depths, it not only delays germination but also reduces the rate and percentage of germination and subsequently reduces the plant growth. Consequently, the increased damage from pests and diseases are not beyond expectation following the weak seedling vigor (16; 15). Therefore, determining the appropriate planting depth increases seed vigor, seedling growth and crop yield.
3.7 Number of Branches
The simple interaction of planting date and depth had a significant effect on the number of branches at 1% confidence level (Table 3). The mean comparison of the interaction of factors showed that the number of branches decreased gradually by increasing the planting depth in both planting dates. The minimum number of branches was observed at the planting depth of 14 cm per the crop year in comparison to the other treatments of planting depth in the same year. In general, the maximum number of branches was observed at the planting depths of 1 to 4 cm in the first planting date while the minimum number of branches was observed at the 10–14 cm planting depth in the second year (Table 4). The results of the present study were in line with the findings of Biabani et al. (13); they confirmed the increase of the number of lateral branches in lentil at appropriate planting depths (1–7 cm).
3.8 Seedling Dry Weight
The interaction of planting date and depth of planting had a significant effect on seedling dry weight at %1 confidence level (Table 3). The mean comparison of the interaction of factors showed that the seedling dry weight was higher in for all planting depths in the first planting date in November compared to all planting depths of the winter planting date. However, shallower depths showed higher seedling dry weight that greater planting depths. In general, the maximum seedling dry weight was observed at the planting depths of 1 and 2cm while the minimum dry weight was witnessed at the 14cm planting depth in the winter planting date (Table 4). Therefore, it increased the height and biological yield of the plant.
Marvi (9) investigated the effect of planting date on lentil. He showed that plant dry weight, plant height and number of lateral branches were higher in early planting date than other planting dates. Yazdi Samadi and Peighambari (23) had a 3-year study of the effect of planting date and plant density on lentil agronomic traits in Karaj. The results indicated that the maximum crop yield was obtained from the early planting date while the minimum crop yield was resulted from late planting date. It seems that inappropriate environmental conditions in the second planting date led to slower leaf area development, shorter height, fewer branches, poorer vegetation development, less radiation absorption, shorter growth period and, in turn, decreased the dry matter production. However, shallower and deeper planting depths decreased the dry weight of lentil seedlings. The findings of the present study were in line with the results of Biabani et al (13).
3.9 Leaf Area
As displayed in ANOVA table, the simple interaction of planting date and depth had a significant effect on the leaf area at 1% confidence level (Table 3). The mean comparison of planting date × planting depth showed that leaf area decreased gradually by increasing the planting depth from 2 cm to greater depths. The minimum leaf area was observed at the planting depth of 14 cm in both planting dates. In general, the maximum leaf area was observed at the 2cm planting depth in the first planting date in November (Table 4). The presence of appropriate environmental factors in the first planting date as well as desired solar radiation and temperatures during seedling establishment and germination increase the photosynthesis yield and subsequently increase the leaf area in this planting date. The growth rate and appropriate leaf area decreased by postponing the cultivation due to the lack of vegetation, low light absorption and winter frost. Moreover, factors such as low rate and percentage of germination, lack of uniformity and increased time to germination had a crucial role in the reduction of leaf area. Biabani et al. (13) showed that the planting depths of 1–7 cm had a positive effect on the leaf area of lentil while the leaf area decreased at the planting depths greater than 10 cm.