Electronic Journal of Polish Agricultural Universities (EJPAU) founded by all Polish Agriculture Universities presents original papers and review articles relevant to all aspects of agricultural sciences. It is target for persons working both in science and industry,regulatory agencies or teaching in agricultural sector. Covered by IFIS Publishing (Food Science and Technology Abstracts), ELSEVIER Science - Food Science and Technology Program, CAS USA (Chemical Abstracts), CABI Publishing UK and ALPSP (Association of Learned and Professional Society Publisher - full membership). Presented in the Master List of Thomson ISI.
2015
Volume 18
Issue 1
Topic:
Agronomy
ELECTRONIC
JOURNAL OF
POLISH
AGRICULTURAL
UNIVERSITIES
Podlaski S. , Chrobak Z. , Wzorek H. , Gozdowski D. 2015. QUALITY ASSESMENT OF SEEDS OFFERED ON THE POLISH MARKET AND EFFECT OF SEED VIGOUR ON ROOT YIELD OF SUGAR BEET, EJPAU 18(1), #01.
Available Online: http://www.ejpau.media.pl/volume18/issue1/art-01.html

QUALITY ASSESMENT OF SEEDS OFFERED ON THE POLISH MARKET AND EFFECT OF SEED VIGOUR ON ROOT YIELD OF SUGAR BEET

Sławomir Podlaski1, Zofia Chrobak1, Hanna Wzorek1, Dariusz Gozdowski2
1 Department of Plant Physiology, Warsaw University of Life Sciences – SGGW, Poland
2 Department of Experimental Design and Bioinformatics, Warsaw University of Life Sciences - SGGW, Poland

 

ABSTRACT

Presented results concerning 2 groups of research a) on quality assessment of seeds belonging to 2 Polish and 5 foreign companies, offered on Polish market between 2011–2013, b) on the effect of seed vigour on yield of beet roots. This research was conducted between 2007–2013. The seeds of 58 sugar beet varieties offered on the Polish market differed in vigour level among companies, among varieties within a single company, and years of sale. The magnitude of plant emergence in a phytotron 12 days after seed sowing time, in compost soil (temperature 10ºC and moisture content 60% Fresh Water Content fluctuated from 13.3 to 83.4% depending on the seed company. The speed of one plant emergence estimated at the end of the emergence period oscillated from 11.43–14.25 days. According to the regression equation each 1% increment in a phytotron, emergence increased the yield of roots by 0.247 t·ha-1. Low vigour of seeds belonging to 5 companies decreased the potential yield by 5.3 to 17.2 t·ha-1 in relation to seeds of the 2 best seed companies. Each seed company is able to offer seeds of the best quality on the Polish market. Sales of low quality seeds is determined by the general sale policy of seed companies and methods of Polish market treatment in comparison to another national seed market.

Key words: low temperature, emergence value, speed, spread.

INTRODUCTION

Standard germination tests usually give a relatively good correlation between germination and field emergence results in favourable environmental conditions. But germination can fail to indicate the ability of a seed lot to establish a crop in poor field conditions, i.e. cold wet soils. There have been many examples described in a wide range of species where seed lots having equally high laboratory germination show wide differences in field emergence [15]. This failure of the germination test to predict differences in field emergence, particularly in poor field conditions, suggested there is a further physiological aspect of seed quality which has come to be referred to as seed vigour.

Differences in emergence and seedling growth of similar quality of sugar beet seeds have been demonstrated by [4, 9, 11, 17]. A very interesting problem is the impact of seed vigour on crop yield [7, 19]. When low vigour leads to reduced crop establishment this can have an effect on yield. In cereals, due to tillering ability and yield compensation, the direct effect of plant density on yield is limited [15].

Low vigour of sugar beet seeds leads to decreased plant establishment [14], differentiation in plant size on plantations due to different emergence date [5, 6, 8], suboptimal utilization of soil area for growth of sugar beet [8], reduced solar energy interception and greater losses of roots during mechanical harvest due to the greater size variability of sugar beet plants [10, 18].

Because of  the importance of sugar beet seed vigor, some of sugar beet breeding (KWS, Kutno Sugar Beet Breeding Company) or sugar industry companies (British Sugar) started to offer primed seeds. Primed seeds emerge more quickly and strongly than unprimed seeds, particularly, in unfavorable weather conditions. [12, 13]. Final  root  yield  increased by an average 4% compared to unprimed sugar beet seed (www.germains). It is obvious that primed seeds can be treated as being high vigorous.

During the last few years molecular biology has been utilized for estimating seed vigour and improving seed quality by priming [1, 2].

The research goals were:

MATERIALS AND METHODS

Materials
a) Fifty eight commercial beet varieties, belonging to 5 foreign (Maribo, Syngenta, Strube, KWS, SES/VdH) – and 2 Polish (Kutnowska Hodowla Buraka Cukrowego – KHBC and Wielkopolska Hodowla Buraka Cukrowego – WHBC) seed companies, offering seeds on the Polish market, between 2011 and 2013. Data came from our research carried out as part of the Post-registration Variety and Agricultural Testing (Porejestrowe Doświadczalnictwo Odmianowe i Rolnicze, PDOiR), conducted by the Research Centre for Cultivar Testing (Centralny Ośrodek Badania Odmian Roślin Uprawnych, COBORU).  Assessment of the emergence in a phytotron, in soil was performed as part of PDOiR coordinated by the COBORU. The number of varieties of each company participating in PDOiR is given in Table 3 (second column).

b) Twenty one, non-primed, seed lots belonging to 7 varieties of Kutnowska Hodowla Buraka Cukrowego – KHBC (Jabeta, Lubelska, Jarysa, Poljana, Jagoda, Janosik and Jagusia), assessed in 2007–2013, pelleted according to the standard technology of this company. Within each variety, seeds of low and high vigour were used. The course of emergence in a phytotron, was the criterion for assessing seed vigour. Additionally, seed vigour was differentiated by using priming following WULS  (Warsaw University of Life Sciences) technology, patent No. P 216898 from 1.04.2011. As a result, non primed seeds of a single variety, with low and high  vigour, produced according to KHBC technology   and primed or  non primed, manufactured after WULS pattern were sowed each year of research. In total, we had seeds with 6 different vigour levels (experimental combinations) at our disposal each year (Tab. 1).Characteristic of seed lots used at experiment was presented at Table 2.

Field experiments, for beet yield assessment were performed in cooperation with sugar manufacturing companies (Krajowa Spółka Cukrowa, Nordzücker, Südzucker) and KHBC in 10 localities in Poland, from Chełmno Pomorskie in the north of Poland to Sandomierz in the south. These experiments were conducted under  standard cultivation conditions, recommended by  sugar manufacturing company for each localization. The distance between seed in rows was 15–18 cm. Root yield, percentage content of sugar and technological yield of sugar were determined in the experiments. Technological yield of sugar was calculated following the Reinefeld  [16] formula.

Since seed vigour level was not observed to have had any effect on the percentage of sugar content in the experiments, only root yield is presented in the study.

Table 1. Seed lots and method of calculating differences in root yield and sugar beet seed emergence in a phytotron
Specification
Seed vigour level
High
Low
High
Low
Primed (P) or non primed (NP) seeds.
NP
P
NP
P
NP
Number of experimental combinations
1
2
3
4
5
6
Differences between
1. High and low vigour of seeds produced according to Kutnowska Hodowla Buraka  Cukrowego technology
2. Primed and non primed seeds.Warsaw University of Life  Sciences technology
3. Primed and non primed seeds.Warsaw University of Life Sciences technology

Table 2. Characteristics of seed lots with  averages for 7 varieties and 21 seed lots, means for 2011–2013
 
Characteristics
Seed vigour level
High
Low
High
Low
Primed (P) or non primed (NP) seeds.
NP
P
NP
P
NP
Phytotron emergence [%]
60.0
57.8
65.2
54.8
58.3
51.3
Speed of emergence [days]
14.11
14.49
13.63
14.58
13.87
15.11
Spread of emergence [days]
2.62
2.89
2.55
2.89
2.68
2.92

Table 3. Assessment of phytotron emergence 12 days after sowing, in soil, and in a phytotron, means for 2011–2013
Company
Number of varieties
Average emergence [%]
Emergence values [%]
Standard deviation for the sample
Variation coefficient [%] for the sample
Min.
Max.
Maribo
4
83.4 c*
78.9
95.6
13.98
16.8
Syngenta
6
68.7 c
44.4
91.1
18.46
26.9
Strube
12
56.6 bc
0.0
100.0
41.47
73.2
KWS
11
35.1 ab
0.0
82.2
31.42
89.5
KHBC
9
29.4 a
5.5
82.2
23.26
79.1
WHBC
5
22.4 a
0.0
87.7
38.0
169.5
SES/VdH
11
13.3 a
0.0
63.3
19.6
147.1
*Means denoted by different superscript letters are significantly different at p=0.05

Methods
a) determination of the course of beet emergence in a phytotron.

The emergence in a phytotron was determined after sowing  100 seeds  in 3 replications at 2 cm depth, into compost soil of 60% field water capacity. Air temperature in the phytotron, 10°C ± 1°C. Emerging plants were counted daily and labelled.

To assess the emergence speed and spread the Pieper Coefficient was used [10], i.e. the mean time of one plant emergence or average time of emergence spreading. The Pieper Coefficient is determined by the formula:

Pieper Coefficient = Σ(dn·an) / Σan

where
dn is a current emergence day,
an is a current day number of emerged plants.

When assessing the speed of emergence, the sowing day is assumed to be first day of emergence (d1), whilst when the spread of emergence is assessed the assumption is that the first day (d1) is the day when first plant emerged of a given seed sample.

In the case of speed and spread of emergence, a higher number indicates slower and more extended emergence.

b) statistical calculations

One way analysis of variance and multiple comparisons at 0.05 probability level were conducted to compare means. The statistical analyses were performed in Statistica 10 (StatSoft).

The variability of characteristics was determined by calculating the standard deviation from a sample and the variation coefficient. The relationship between the magnitude increase of field emergence determined 12 days after seed sowing in the phytotron (a vigour level measure) and root yield increase in each year was calculated using a regression and pair correlation.

In each year of research, having seeds of a single variety with 6 vigour levels, 3 differences in emergence levels in a phytotron could be calculated following the above method. Differences in yield between various combinations of seed vigour were calculated in the same way. Using the differences in beet yields, the effect of environment on yields could be eliminated, as it affected beets grown from seeds of low and high initial vigour, primed or not, in the same way.

c) calculation of the effects of varied beet emergence in a phytotron on possible beet yields under production conditions.

The COBORU experiments serve to ascertain the genetically determined beet yielding. Thus, seeds are densely sown and subsequently thinned out, leaving an optimum beet establishment. Under such conditions, differences in seed vigour can not become visible.

The effects of varied vigour levels on root yields were calculated as follows. The average emergence results for the 2 best companies, Maribo  and Syngenta, were assumed as standard. A decrease of emergence for each company was calculated in relation to the standard. The magnitude of emergence difference for each company was multiplied by a regression slope of 0.274. This way, information on possible root yield losses corresponding to a specific decrease in emergence was obtained. Possible beet crops under production conditions were calculated from the difference between root yield in accordance with official COBORU data and the decrease in yield resulting from lower emergence.

RESULTS

Data concerning averages and variability of phytotron emergence for all varieties of each company between 2011 and 2013  are presented in the Table 3. Based on the data, it can be stated that average beet emergence is highly varied in the Polish market. The best seeds are offered by the  Maribo and Syngenta companies. Similarly, a high variation in seed quality is visible for individual years, even within the same variety. For example, the emergence of plants belonging to the Konrad variety by the company Strube in a phytotron after 12 days, were 93.3% in 2011 and 5.4% in 2013 (data not shown).

Considering the variation coefficients, it can be stated that seeds:

The high maximum emergence values indicate that every company is able to offer seeds of the highest quality to Polish growers.

Results for value and variability of emergence speed after it was finished, are presented in Table 4. The average emergence speed for the given plant partially corresponds to the average emergence value. The significantly lowest speed of germination was exhibited by seeds of the company SES/VdH.  Seeds of the company KHBC were characterised by the lowest standard deviation and the lowest coefficient of variation of emergence speed. This indicates a stable quality of seeds offered by this company in relation to the discussed attribute. The highest variability of emergence speed was observed for seed of Strube company. Plant emergence from seeds of this company was relatively high and  quick, although a high variability of this attribute over the years was noted. An example is the Sinan variety, whose average germination speed for a single plant was 12.3 days in 2012, but as much as 16.0 days in 2013, which denotes a difference of almost 31% (data not shown).

Table 4. Assessment of final emergence spread for single plants, means for 2011–2013
Company
Average spread of emergence [day]
Emergence spread values [day]
Standard deviation for the sample
Variation coefficient [%] for the sample
Min
Max.
Maribo
2.55 a*
1.9
3.6
0.73
28.6
Syngenta
3.12 ab
2.3
4.1
0.60
19.2
Strube
2.94 ab
1.3
3.7
0.75
25.5
KWS
3.47 ab
1.8
4.4
0.86
24.8
KHBC
3.66 b
2.4
5.1
0.86
23.5
WHBC
2.82 ab
1.6
3.4
0.75
26.6
SES/VdH
3.35 ab
2.4
4.5
0.60
17.9
*Means denoted by different superscript letters are significantly different at p=0.05

Spread of emergence is determined by the average time of emergence from the moment it starts, regardless of how quickly it started. The results for spread were not as clear as those for the high and speed of emergence (Tab. 5). Considering the average values, plants grown from seeds of the company Maribo emerged the most uniform, comparing to  KHBC seeds. Due to high variability in years  of the research there were no significant differences between spread of emergence of plants belonging to Maribo, Syngenta, Strube KWS, WHBC and SES/VdH. companies. At the same time, the Maribo varieties were characterised by the highest variation coefficient and had the best results for value and speed of emergence. The company SES/VdH offered the most evenly germinating seeds, which was indicated by the lowest variation coefficient of this attribute.

Table 5. Assessment of  final emergence speed for single plants, means for 2011–2013
Company
Average speed of emergence [day]
Emergence speed values [day]
Standard deviation for the sample
Variation coefficient [%] for the sample
Min.
Max.
Maribo
11.43 a*
10.3
11.7
0.82
7.1
Syngenta
11.72 a
10.0
11.6
0.84
7.2
Strube
12.35 a
10.3
11.9
1.92
15.5
KWS
13.37 a
11.2
12.0
1.16
8.7
KHBC
13.23 a
10.9
12.0
0.80
6.0
WHBC
14.06 ab
11.3
12.5
1.49
10.6
SES/VdH
14.25 b
11.0
14.3
1.19
8.35
* Means denoted by different superscript letters are significantly different at p=0.05

Results for final emergence value  (30 days after sowing) are presented in the Table 6.

Table 6. Assessment of final plant emergence, means for 2011–2013
Company
Average final emergence [%]
Emergence values [%]
Standard deviation for the sample
Variation coefficient [%] for the sample
Min.
Max.
Maribo
97.0 b*
91.1
100.0
4.00
4.10
Syngenta
95.8 ab
87.8
100.0
4.40
4.59
Strube
97.8 b
94.3
100.0
2.25
2.30
KWS
95.6 ab
87.8
100.0
3.74
3.91
KHBC
96.3 ab
91.1
100.0
3.15
3.27
WHBC
95.4 ab
90.0
97.8
3.10
3.25
SES/VdH
92.5 a
85.5
96.7
3.44
3.72
*Means denoted by different superscript letters are significantly different at p=0.05

The minimum values of final plant emergence ranged from 85.5 to 94.3%, while maximum values reached 100%. This data indicates that seeds of all companies met the basic requirements for quality,. The significantly lowest final plant emergence was exhibited by seeds of the company SES/VdH, comparing to Maribo and Strube companies.

Based on research conducted in 2007–2013, it was determined that increment of plant emergence in phytotron (within the range of 2.2 to 46.6 – 19.4% on average) of various seed lots, comparing to lower level of seed vigour (differences 1, 2, 3 – Tab. 1),  results in increases of root yields of beets cultivated in the same location and in the same year, ranging from 0.2 to 12.7 t·ha-1. Presenting these relationships in the form of  regression equation, one can note that an increase in emergence in a phytotron after 12 days of assessment by 10% corresponds to an increase of root yield in the field by 2.7 t·ha-1 (Fig.1).

Fig. 1. HPLC chromatogram for artichoke sample after extraction

Using the regression equation slope, one can note that the possible decrease in root yield for varieties of the Strube, KWS, KHBC, WHBC and SES/VdH companies ranged from 5.3 to 17.2 t·ha-1 (Tab. 7). This was a result of lowered emergence, which is a measure of seed vigour. As a result, possible yields obtained under production conditions decreased with the increase of possible crop losses.

Table 7. Possible effect of lowered plant emergence, determined 12 days after the date of sowing – on beet root yield, means for  2011–2013
Company
Average emergence after 12 days [%]
Difference of emergence to standard* [%]
Potential yield reduction [t·ha-1]
Average root yield according to  PDOiR[t·ha-1]
Potential root yield in production
[t·ha-1]
a
b
c
d = c × 0,274
e
f = e – d
Maribo
83.4
Standard=76.1
0.0
77.43
77.43
Syngenta
68.7
0.0
79.70
79.57
Strube
56.6
19.5
5.3
80.39
75.09
KWS
35.1
41.0
11.2
81.30
70.10
KHBC
29.4
46.7
12.8
82.87
70.07
WHBC
22.4
53.7
14.7
82.87
68.17
SES/VdH
13.3
62.8
17.2
78.55
61.35
* standardrefers to average emergence for varieties in the Maribo and Syngenta companies

DISCUSSION

The acquired results indicate that seeds of all companies are characterised by high final emergence, determined at the low temperature of 10°C. Its variability is the effect of differences in vigour level, which was assessed according to the course of emergence in a phytotron. Low-vigour seeds provide acceptable plant density [13] and guarantee quick plant growth only under favourable environmental conditions. Under unfavourable conditions, low vigour of seeds usually reduces emergence and root yield. Considering these facts, it is clear that offering seeds of not the highest vigour in the Polish market is determined by policies of individual companies, who treat the Polish market in a worse manner than markets of Western European countries.

It is difficult to assess the effects of seed vigour on root yield. Previously, we had a similar opportunity in 1998, when results of variety testing (10 varieties) in Straszków (dense sowing, plant singling) were compared to production results in Chodów (seeds sowed every 18 cm) [10]. Both places are located within 7 km of each other, thus it can be assumed that environmental conditions were identical. Under production conditions in Chodów, those varieties characterised by a higher germination ability of seeds, determined after 4 days and field emergence, plant density higher by ca.4 thousands plants per hectare and lower root losses during harvest demonstrated better results than in Straszków. All these attributes are related to high seed vigour.

Climate changes will be accompanied by unexpected weather phenomena, such as extremely low temperatures or droughts. In spring 2013, average air temperatures at plantations in Western Europe were 6°C lower than long term averages. As a result, significant problems with beet emergence occurred, especially in Great Britain. It can be assumed that such extreme weather conditions will repeat more frequently than to date. Under such conditions, the role of seed vigour becomes more significant and a need for developing methods that enable quick assessment of vigour for crop emergences. British Sugar representatives suggest that seed companies should conduct seed quality assessment at 7°C [20].

CONCLUSIONS

  1. In the Polish market, a high variability in seed vigour exists among companies, varieties and sale years.
  2. The highest differences in seed vigour were observed  in emergence after short periods of time (12 days after sowing) and in emergence speed. Essentially, both parameters can be considered as measures of emergence speed.
  3. The best quality of seeds,  between 2011–2013  offered Maribo and Syngenta companies.
  4. A decrease of emergence of  sugar beets plants  in phytotron, belonging to different seeds companies, from  19.5 to 62.8%  comparing to standard (Maribo, Syngenta varieties) could be potentially accompanied by a decrease in root yield from 5.3 to 17.2 t·ha-1
  5. Based on the regression equation, it was determined that each difference in plant emergence value in a phytotron of 1% (within 2.2 to 46.6%) corresponds to a drop/increase in yields by 0.274 t·ha-1.
  6. All companies are capable of preparing seeds with the highest quality parameters. Offering lower quality seeds is determined by the sales policies of seed companies and the manner in which the Polish market is treated.

Acknowledgment

In our publication we partly used results obtained from scientific grant number PBS 1/A8/15/2013, financing by the Ministry of Science and Higher Education of the Republic of Poland.

We thank the Research Centre for Cultivar Testing in Słupia Wielka for using research results conducted in Post-registration Sugar Beet Variety Testing.

Supplement

Table 1. List of sugar beet cultivars from each company  in 2011–2013
Companies
Years
Total
Maribo
2011
2012
2013
4
Delano
Milton
Milton
Pikador
Syngenta
Silvetta
Alegra
Alegra
6
Belana
Belana
Belana
Strube
Tuwim
Sokrates
Konrad
12
Schubert
Konrad
Sinan
Sokrates
Sinan
Basilius
Konrad
Gellert
Abrax
KWS
Danuśka
Danuśka
Danuśka
11
Primadonna
Primadonna
Primavera
Oliviera
Natura
Natura
Nevenka
Steffka
KHBC
Janosik
Szach
Szach
8
Finezja
Finezja
Finezja
Luzon
Luzon
WHBC
Huzar
Huzar
Telimiena
6
Tadeusz
Tadeusz
Jampol
SES/VdH
Agronom
Agronom
Manitou
11
Argument
Argument
Alarm
Pasja
Pasja
Splendor
Fighter
Ambasador
Total
21
18
19
58

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Accepted for print: 19.01.2015
Sławomir Podlaski
Department of Plant Physiology,
Warsaw University of Life Sciences – SGGW, Poland
Nowoursynowska 166 St.
02-787 Warsaw, Poland
Phone +48 22 59 325 21
email: slawomir_podlaski@sggw.pl

Zofia Chrobak
Department of Plant Physiology,
Warsaw University of Life Sciences – SGGW, Poland
Nowoursynowska 166 St.
02-787 Warsaw

Hanna Wzorek
Department of Plant Physiology,
Warsaw University of Life Sciences – SGGW, Poland
Nowoursynowska 166 St.
02-787 Warsaw

Dariusz Gozdowski
Department of Experimental Design and Bioinformatics, Warsaw University of Life Sciences - SGGW, Poland
Nowoursynowska 159
02-776 Warsaw
Poland
Phone: +48 (22) 59 32 730
email: dariusz_gozdowski@sggw.pl

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