Abstract
Field experiments were conducted during three successive winter seasons 2010/11, 2011/12 and 2012 /13, at Shambat Research Station Farm on clay loam soil pH 7.8, to study the effects of seed bed, cultivars and seed rates and their interactions on onion set yield and quality. Two seed bed (flat and ridge), two cultivars Kamleen and Baftaim (S) and three seed rates 4, 8, 12 g / m² (40, 80, 120 kg / ha) were tested. The experimental design used was 2*2*3 Factorial in spilt-split plot design with four replications. Yield was evaluated as set yield t / ha, whereas, quality was evaluated as percentage of large (2.9-2.0 cm) and medium (1.9-1.0 cm) set size according to diameter and average of single set weight (g). Cultivar Baftaim (S) gave the highest set yield t/ha and average of single set weight in the three seasons. The seed rate of 4 g/m² (40 kg / ha) resulted in highest average of single set weight and the highest number percentage of large set size. Increasing the seed rate increased set number and quality; the seed rate 12 g/m² (120 kg/ha) gave the highest percentage of medium set size.
Author Contributions
Copyright© 2022
A. Mohammedali Aisha, et al.
License
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This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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Introduction
Onion ( In the Sudan it ranks the first vegetable with regard to the area grown and quantities produced. It grown in different states in the Sudan (Naher El -Neil, Gezira, Darfur States, Kassala, Northern State and Khartoum) Onion is grown by one of three methods: direct sowing, transplanting and sets The present study is conducted to find a suitable combination of seed bed, cultivar and seed rate for the production of sets for onion off-season production.
Materials And Methods
The experiments were carried out during three successive winter seasons (2010/11, 2011/12 and 2012/13), at Shambat Research Station Farm on clay loam soil pH 7.8 (lat. 15° 39 N long. 32° 32 and 381m above sea level). The experiments were designed to test the effect of two seed bed (flat vs. 60 cm ridges), three seed rates 4, 8 and 12 g /m² (40, 80 and 120 kg /ha) on the sets yield and quality of the two onion cultivars, Kamleen Yellow and Baftaim (S) Red. The experimental units were 2*2*3 Factorial in split-split plot design with four replications. The planting methods were assigned to the main plots, onion cultivars in the sub-plots and the seed rates in sub-sub plots. The total net area of each sub-sub plot was 10.44m² (1.8 m. * 5.8 m.). Before laying out the experiments, the field was disc ploughed, well leveled and divided to flat and 60 cm ridge plots. The seeds were drilled in rows 20cm apart (9 rows/plot) in flat and 3 rows/ridge on ridged plot. The experiments were sowing in 6, 11 and 14-15 Januarys, and all agronomic practices (fertilization, irrigation and weeding… etc) were done as recommended in the three seasons. All the experimental plots were fertilized with nitrogen (43 kg N/ha) in the form of Urea (46%N) in two equal doses. At harvesting, an area of 1m² was harvested randomly to evaluate yield as set number and weight and yield/h and quality (percentage of different set size). Harvested sets were cured and graded large (2.9 - 2.0 cm) and medium (1.9 - 1.0 cm) according to the diameter, the yield per hectare was calculated as follow: Yield (t/ha) = (Yield/m2*10000)/1000 The data were analyzed using GenStat (Computer Program) Version4 and the means were separated using Duncan Multiple Range Test (DMRT) at P≤0.05
Results
Both cultivars differenced significantly in their yield irrespective of seed bed or seed rate ( N.B.: NS, *, ** and ***, non significant at P=0.05 and significant at P=0.05, P=0.01 and P=0.001 respectively. Means with similar letters are not significant at P=0.05 according to DMRT. As in N.B.: NS, *, ** and ***, non significant at P=0.05 and significant at P=0.05, P=0.01 and P=0.001 respectively. Means with similar letters are not significant at P=0.05 according to DMRT. N.B.: NS, *, ** and ***, non significant at P=0.05 and significant at P=0.05, P=0.01 and P=0.001 respectively. Means with similar letters are not significant at P=0.05 according to DMRT The three seasons mean indicated significant effect was observed on single set weight between seed bed, flat sowing obtained highest single set weight. Also, the cultivar had high significant effect on the single set weight; Baftaim (S) gave the highest single set weight, also the three seed rates had highly significant effect on single set weight; the highest set weight was recorded by the low seed rate of 4 g / m² in all seasons ( N.B.: NS, *, ** and ***, non significant at P=0.05 and significant at P=0.05, P=0.01 and P=0.001 respectively. Means with similar letters are not significant at P=0.05 according to DMRT. N.B.: NS, *, ** and ***, non significant at P=0.05 and significant at P=0.05, P=0.01 and P=0.001 respectively. Means with similar letters are not significant at P=0.05 according to DMRT.
Sowing Methods
Season
Mean
2010/11
2011/12
2012/13
Flat
39.69 a
48.29 a
31.52 a
39.84 a
Ridge
37.58 a
52.56 a
30.26 a
40.13 a
Sig.
NS
NS
NS
NS
S.E
1.72
1.405
0.625
0.844
Cultivars
Kamleen
28.72 b
43.93 b
24.09 b
32.25 b
Baftaim(S)
48.55 a
56.92 a
37.70 a
47.72 a
Sig.
***
***
***
***
S.E
1.82
1.159
0.805
0.844
Seed rates
4 g/m²
37.01 a
51.68 a
28.68 a
39.12 a
8 g/m²
40.48 a
50.26 a
31.77 a
40.84 a
12 g/m²
38.43 a
49.34 a
32.23 a
40.00 a
Sig.
NS
NS
NS
NS
S.E
1.94
1.160
1.529
1.033
C.V.%
20.1
9.2
19.8
17.9
Sowing Methods
Seed rates
Season
Mean
2010/11
2011/12
2012/13
Flat
4 g/m²
36.67 a
47.43 bc
28.36 a
37.49 a
8 g/m²
40.63 a
49.41 abc
26.80 a
40.89 a
12 g/m²
41.83 a
50.13 abc
24.52 a
41.44 a
Ridge
4 g/m²
37.34 a
55.92 a
36.43 a
40..76 a
8 g/m²
40.08 a
53.21 ab
36.74 a
41.14 a
12 g/m²
35.31 a
48.54 c
39.93 a
38.61 a
Sig.
NS
*
NS
NS
S.E
2.82
1.941
1.873
1.461
Sowing Methods
Season
Mean
2010/11
2011/12
2012/13
Flat
40.13 a
43.66 a
38.89 a
40.89 a
Ridge
31.00 b
39.16 a
32.13 b
34.10 b
Sig.
*
NS
*
***
S.E
1.95
1.69
1.47
0.843
Cultivars
Kamleen
33.03 b
44.19 a
36.23 a
37.82 a
Baftaim(S)
38.09 a
38.63 a
34.79 a
37.17 a
Sig.
*
NS
NS
NS
S.E
1.51
2.09
1.09
0.843
Seed rates
4 g/m²
53.31 a
52.13 a
47.38 a
50.94 a
8 g/m²
36.27 b
42.27 b
35.80 b
38.11 b
12 g/m²
17.12 c
29.82 c
23.35 c
23.43 c
Sig.
***
***
***
***
S.E
1.71
2.05
1.40
1.032
C.V.%
19.3
19.8
15.8
19.1
Sowing Methods
Cultivars
Season
Mean
2010/11
2011/12
2012/1 3
Flat
Kamleen
38.08 a
46.78 a
41.54 a
42.13 a
Baftaim (S)
42.18 a
40.53 a
36.25 ab
39.65 a
Ridge
Kamleen
27.98 a
41.60 a
30.92 b
33.50 a
Baftaim (S)
34.01 a
36.73 a
33.33 b
34.69 a
Sig.
NS
NS
*
NS
S.E
2.468
2.69
1.834
1.92
Sowing Methods
Season
Mean
2010/11
2011/12
2012/1 3
Flat
41.96 a
36.50 a
36.37 a
38.28 b
Ridge
46.76 a
38.65 a
40.77 a
42.06 a
Sig.
NS
NS
NS
**
S.E
2.90
2.397
2.473
0.784
Cultivars
Kamleen
46.64 a
37.97 a
40.18 a
41.60 a
Baftaim(S)
42.08 b
37.18 a
36.96 a
38.74 b
Sig.
**
NS
NS
*
S.E
0.89
1.349
1.755
0.784
Seed rates
4 g/m²
30.15 b
23.37 c
24.48 c
26.00 c
8 g/m²
49.12 a
39.77 b
40.90 b
43.26 b
12 g/m²
53.81 a
49.59 a
50.34 a
51.25 a
Sig.
***
***
***
***
S.E
2.47
1.715
1.563
0.960
C.V.%
22.3
18.3
16.2
20.4
Sowing Methods
Seedrates
Season
Mean
2010/11
2011/12
2012/13
Flat
4 g/m²
24.73 d
21.18 a
22.86 a
22.92 a
8 g/m²
43.74 bc
39.69 a
38.08 a
40.50 a
12 g/m²
57.41 a
48.62 a
48.17 a
51.40 a
Ridge
4 g/m²
35.57 cd
25.55 a
26.09 a
29.07 a
8 g/m²
54.50 ab
39.85 a
43.72 a
46.02 a
12 g/m²
50.20 ab
50.56 a
52.50 a
51.09 a
Sig.
*
NS
NS
NS
S.E
4.07
3.109
3.061
1.672
Sowing Methods
Season
Mean
2010/11
2011/12
2012/13
Flat
5.71 a
6.42 a
6.60 a
6.24 a
Ridge
4.76 a
6.58 a
5.62 a
5.66 b
Sig.
NS
NS
NS
**
S.E
0.381
0.348
0.284
0.205
Cultivars
Kamleen
4.09 b
6.12 b
5.34 b
5.18 b
Baftaim(S)
6.39 a
6.89 a
6.89 a
6.72 a
Sig.
**
*
*
***
S.E
0.353
0.192
0.382
0.205
Seed rates
4 g/m²
7.90 a
9.17 a
9.06 a
8.71 a
8 g/m²
4.71 b
6.11 b
5.72 b
5.52 b
12 g/m²
3.10 c
4.22 c
3.55 c
3.62 c
Sig.
***
***
***
***
S.E
0.201
0.238
0.421
0.251
C.V.%
15.4
14.6
27.5
22.8
Cultivars
Seedrates
Season
Mean
2010/11
2011/12
2012/1 3
Kamleen
4 g/m²
6.06 b
8.89 a
8.28 a
7.74 b
8 g/m²
3.82 c
5.54 b
4.68 a
4.68 c
12 g/m²
2.39 d
3.92 b
3.05 a
3.12 c
Baftaim(S)
4 g/m²
9.75 a
9.45 a
9.85 a
9.68 a
8 g/m²
5.61 b
6.69 a
6.76 a
6.35 b
12 g/m²
3.81 c
4.52 b
4.05 a
4.13 c
Sig.
**
**
NS
NS
S.E
0.423
0335
0.618
0.355
sowing methods
Cultivars
Seedrates
Season
Mean
2010/11
2011/12
2012/1 3
Flat
Kamleen
4 g/m²
6.61 a
9.03 ab
9.00 a
8.24 a
8 g/m²
4.25 a
4.99 ef
4.85 a
4.70 a
12 g/m²
2.59 a
4.21 f
3.46 a
3.42 a
Baftaim (S)
4g/m²
10.32 a
8.27 bc
10.69 a
9.76 a
8g/m²
6.08 a
7.48 cd
7.29 a
6.95 a
12g/m²
4.43 a
4.55 ef
4.20 a
4.39 a
Ridge
Kamleen
4g/m²
5.51 a
8.76 bc
7.48 a
7.25 a
8g/m²
3.39 a
6.08 de
4.51 a
4.66 a
12g/m²
2.18 a
3.63 f
2.63 a
2.81 a
Baftaim (S)
4g/m²
9.15 a
10.63 a
9.00 a
9.61 a
8g/m²
5.15 a
5.90 f
6.23 a
5.76 a
12g/m²
3.19 a
4.50 f
3.89 a
3.86 a
Sig.
NS
**
NS
NS
S.E
0.615
0.556
0.836
0.392
Discussion
The results reflected that the set yield was significantly affected by cultivars, while there was no affect either due to seed bed or seed rate. These results agreed with Increasing of seed rate showed significant negative effect on set size, whereas the highest percentage of large set size was obtained by the lowest seed rate. The highest seed rate, however, gave the highest percentage of medium sets size (considered the optimum set size for off-season onion production). Similar results were also obtained by The single set weight affected significantly by cultivars and seed rate, this result confirmed with It can be concluded that in order to achieve high yield and quality of onion sets; sowing on ridge (60 cm) and seed rate 12 g/m² (120 kg/ha) irrespective of cultivars for high onion sets yield an quality for off-season production.