Abstract
The main objective of this study was to quantify the influence of sowing date on growth and yield components of hybrid sunflower (Hysun33) cultivar in semi-arid zone. This experiment was conducted during the seasons 2014/2015-2015/2016 at the farm of the College of Agricultural Studies, Sudan University of Science and Technology, Shambat, Khartoum- Sudan. The experiment was arranged in randomized complete block design (RCBD) with four replications and three treatments. Different parameters were considered including plant height, leaf area index (LAI), filled sees number/head, head diameter, dry weight and yield components. The collected data were statistically analyzed. The results revealed that crop sown in May and July showed significant increase in plant height, LAI, head diameter, dry weight, field seed number/head, weight of 100 seeds; yield; and yield components; compared to crop sown in March. However, crop sown in the second season showed an increase in growth and yield components compared to the crop of the first season.
Author Contributions
Copyright© 2019
D. Abu Anga Hilwa,, et al.
License
This work is licensed under a Creative Commons Attribution 4.0 International License.
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.
Competing interests The authors have declared that no competing interests exist.
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Introduction
Sunflower ( The economic importance of this crop is that the fresh green plant can be used as silage or fodder to feed livestock. The seed can be eaten raw or roasted, and it can be used in salads, cooking, margarine, lubricant, paint varnishes and soap production. The seed contains about 36 to 45 % oil depending on the variety The crop is categorized as a low to medium drought sensitive It is noticed that good cultural practices and drainage are required for sunflower production It is reported that yield differences between hybrids with regard to sowing time and density are remarkable. These differences are determined on one hand by the hybrid characteristics and environmental conditions, and on the other hand, on by plant population, soil fertility and land preparation Researchers Seed setting and filling problem is one of the most important constraints in sunflower production, especially under rain-fed; where the heavy rains wash the pollen grains, and often considered to be a major reason for low productivity
Materials And Methods
This experiment was conducted at the farm of the College of Agricultural Studies, Sudan University of Science and Technology, Shambat, Khartoum - Sudan, during the seasons 2014/2015 and 2015/2016. Where the climate is described as semi-arid region. The area receives an average annual rainfall in summer, during July to September, ranging from 100 to 160 mm/annum, and relative humidity ranges between 31-51% during the wet season and 12-27% during the dry season. The average maximum and minimum temperature is about 41.7 0C and 15.3 0C respectively. The winter season begins in November and ends in March. It is relatively cool and dry The soil of study area is classified as silt, clay loam with non saline at surface, but slightly sodic at the subsurface. The adopted experimental design was the randomized complete block (RCBD); with four replications and three treatments (sowing dates (March, May and July)) which referred as S1, S2 and S3 respectively. The land was cleared, well prepared by using disc plough, disc harrow, leveler and moldboard. Then the area was divided into equal plots. Each plot size is 4 X 4 m2, with 5 rows. The spaces between rows are 70 cm. Following the randomization, seeds of sunflower (Hysun 33) were sown on rows, 70X15 cm apart. The recommended cultural practices by the Research Centre in Sudan were followed. The data of the studied parameters were collected. Where three plants were randomly selected from each plot for measuring the following parameters: plant height (cm), leaf area index (LAI), plant dry weight (g), and yield components including head diameter, 100 seeds weight (g), number of seeds/head, yield (t/ha). The collected data were subjected to statistical analysis using statistic 8, Version 2.0 UK. Means in columns followed by different letters are significantly different at 5 %. HyS33= Hysun33 Cultivar. S1= Sowing in March. S2= Sowing in May. S3= Sowing in July. Means in columns followed by different letters are significantly different at 5 %. HyS33= Hysun33 Cultivar. S1= Sowing in March. S2= Sowing in May. S3= Sowing in July. Considering As far as the leaf area index (LAI) concern, in the first season, the sowing date S3 produced bigger LAI (106.13 m2) compared to 94.45 cm2 and S1 59.45cm2 for S1 and S2 respectively. While in the second season; S2 produced the biggest LA I 137.31 m2, followed by S3 and S1 respectively ( For filled seed number/head, the data reflected S1 produced the highest number of seed filling/head (235.54), followed by S3 and S2 (152.75) in the first season ( For seed weight (100 seeds weight), the sowing dates S3 (4.38g.) and S2 (4.2 g) produced higher seed weight in the first season compared to S1 (3.89 g.). While in the second season; the S1 produced more seed weight compared to S3 and S2 ( In regard to head diameter, S2, and S3 appeared to be the suitable sowing dates for sunflower in this area ( The data of the dry weight of the first season reflected that treatment S2 showed higher dry weight (435 g) compared to treatment S2 and S3 375.13 and 365 respectively. While treatment S3 produced more dry weight (262.5 g) compared to treatments S2 (205 g) and S1 (201.85 g) respectively ( As far as the yield concern, the data displayed variation between and within the two seasons. The yield of the first season exceeded the second season. In the first season; crop sown in July produced higher yield, while in the second season; crop sown in May produced higher yield (
Sowing Date
Season1
Plant height (cm)
Leaf area Index (L. A I)
Filled seed No. /head
S1
131.15AB
94.45B
235.54A
S2
136.55A
81.59C
152.75C
S3
128.46B
106.13A
186.69B
SE+
4.04
6.51
15.63
CV
8.23
11.10
31.79
Season11
S1
125.50C
74.26C
240.04C
S2
135.84A
137.31A
289.38B
S3
129.49B
109.57B
316.19A
SE+
3.08
6.60
45.36
CV
6.26
13.42
32.29
Season I
Sowing date
100 seed Weight (g)
Head diameter (cm)
Plant dry weight (g)
Yield t/ha
S1
3.89B
8.38B
365.00B
1.13C
S2
4.20A
9.46A
435.00A
1.13B
S3
4.38A
9.42A
378.13B
1.57A
SE+
0.30
0.44
40.42
5.88
CV
0.61
0.89
52.19
11.96
Season II
S1
1.59A
8.85C
201.88B
0.67B
S2
1.32B
12.38A
205.00B
0.78A
S3
1.33B
11.19B
262.50A
0.71B
SE+
0.14
0.41
35.48
16.30
CV
0.29
0.84
42.24
33.15