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Growing non-food sunflower in dryland conditions
Mario Monotti
Department of Agroenvironmental and Crop
Sciences Section of Agronomy and Crop
Sciences Dipartimento di Scienze Agroambientali e
della produzione vegetale Sezione di Agronomia e
Coltivazioni erbacee Università degli Studi di
Perugia Borgo XX Giugno, 74 I-06121 PERUGIA
(ITALY)
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Introduction

• Sunflower is a very important crop in
  Mediterranean regions where irrigation is not a
  feasible practice
• Since the 1970s, production of this crop has
  spread considerably in Spain, France and Italy

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Reasons for success

• One main reason for the increased production of
  sunflower in Mediterranean regions is its
  adaptability to dryland conditions, thanks to
• early sowing
• short growing cycle
• depth of rooting
• Other technical and economical reasons are
• sunflower is an excellent preceding crop for
  wheat
• all cropping practices can be easily mechanised
• high price of grain yield

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Present trend

• Recent changes in the Community Agricultural
  Policy of UE have considerably reduced the
  economic return of sunflower. Consequently,
  sunflower hectarage has decreased.

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Sunflower hectarage in Spain, France and Italy
during 1997 - 2002
Spain
France
Italy
From Cereol (2003)
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Present trend - 2

• The decrease in economical return from sunflower
  cultivation has created problems in agricultural
  production of Southern European countries
• In Italy, for example, sunflower is traditionally
  grown in sunflower-wheat biennal rotations that
  are particularly suitable for non-irrigated
  regions. In those regions, the decrease in
  sunflower production has created problems, due to
  the lack of possible alternative crops to be
  rotated with wheat

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Non - food sunflower

• One possibility to maintain the interest in
  sunflower is to consider growing this crop for
  industrial oil production
• Oils derived from crops may have several uses in
  industrial processes, depending on their
  physio-chemical characteristics, particularly on
  their fatty-acid composition
• With this respect, sunflower oil is particularly
  interesting, due to its high ratio of oleic acid
  (181).
• Indeed, the special high oleic sunflower
  varieties may play a major role, as oleic acid
  can reach 90 of the total fatty acid content

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High - oleic sunflower

• The high - oleic characteristic was introduced
  into sunflower by Soldatov (1976), through
  chemical mutagenesis.
• In normal varieties
• oleic acid is transformed into linoleic acid by
  the ?-12 desaturase enzyme
• thus, sunflower oil is composed from a mixture of
  the two above mentioned acids

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Storage kinetics of oleic and linoleic acids in
normal varieties
(Baldini et al., 1999)
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High - oleic sunflower

• On high-oleic varieties
• ? -12 desaturase is blocked early after flowering
• thus, only a very small quantity of linoleic acid
  can be produced
• as a consequence, oleic acid is largely the most
  important and predominant fatty acid in the oil

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Storage kinetics of oleic and linoleic acids in
high oleic varieties
(Baldini et al., 1999)
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Problems with high-oleic sunflower

• The first high-oleic varieties released during
  the 1980s exhibited two apparent problems
• oleic acid content was rather low, with respect
  to its potential
• oleic acid content showed remarkable variability,
  depending on environment and year

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Aims of previous experimental work

• Extensive experimental work has been undertaken
  to obtain better results in terms of oleic acid
  content and year to year stability in different
  environments.
• The following effects have been studied
• water availability
• sowing time
• fertilisation
• improved varieties

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Effects of water availability

• One possible reason for variability in oleic acid
  content may be caused by water stress in the
  first days after flowering
• Some authors have demonstrated that stopping
  irrigation from flowering to physiological
  maturity has enhanced the percentage of oleic
  acid in sunflower achenes, compared to water
  regimes based on water layer or full restoration
  of crop ET

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Effect of water regime on oleic and linoleic acid
content of oil from high oleic and normal
sunflower varieties
water table
water table
water table
Water regimes (in lisimeters) water table
water layer maintained at 0,5 m depth
ET
restoring 100 of evapotranspiration
stress
no irrigation from flowering onward irrigation
(Baldini et al., 1999)
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• The above authors advocated that water stress
  causes a more rapid development of embryo
• Consequently, ?-12 desaturase, which on high
  oleic varieties may act only for a few days, has
  an even shorter period of activity under
  water-stressed conditions
• Such an effect was not observed in normal
  varieties, wherein the ?-12 desaturase can retain
  its activity for a longer period of time during
  the whole grain filling phase

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Storage kinetics of oleic and linoleic acids in
normal and high oleic varieties
(Baldini et al., 1999)
Linoleic acid
Oleic acid
100
50
80
40
60
30
Oleic acid ()
Acido linoleico ()
20
40
20
10
0
0
normal variety
high oleic variety
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• However, in spite of the earlier mentioned
  findings, exploiting the effect of water stress
  soon after flowering does not seem to be a
  feasible option to obtain a higher content of
  oleic acid
• Water stress after flowering will likely severely
  reduce grain yield and achene oil content
• Furthermore, other authors showed contrasting
  results sometimes oleic acid content per achene
  can actually increase as water availability
  increases

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Time course of oleic acid content in the akene of
high oleic sunflower as affected by different
irrigation regimes (Santonoceto et al., 1999)
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Effect of sowing time

• In dry areas of Mediterranean regions, early
  sowing is fundamental if sunflower has to be
  grown without irrigation.
• Any sowing delay is likely to negatively affect
  grain and oil yield, as well as oleic acid
  content
• The above reduction is more evident on sunflower
  varieties naturally characterised by a lower
  oleic acid content

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Kinetics of oleic acid content as affected by
normal and delayed sowing dates
Pritoni et al., 1999
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Might autumn sowing be a useful technique for
sunflower?

• In the southernmost European regions, sunflower
  could theoretically be sown during the autumn-
  winter period, which might help the crop avoid
  summer drought and eliminate the need for
  irrigation
• Experimental trials were carried out in Sicily
  (Italy) to compare sowing dates from winter to
  summer. Results showed that the highest oleic
  acid contents were recorded with spring sowing
  while the lowest were recorded with autumn sowing
• Researchers found that oleic acid content may
  reach 80 of total acids by sowing sunflowers in
  the winter period

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Effect of sowing dates on oleic acid content of
high oleic varieties
(Anastasi et al., 2000)
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Effect of N-fertilisation

• Increasing nitrogen rates from 0 to 100 kg/ha did
  not show any significant effect on oleic acid
  content of several high-oleic varieties
  (Pritoni et al., 1999)

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New varieties

• Several new high oleic varieties have been
  recently introduced in Europe, thanks to an
  intensive selection work
• Several new varieties are currently under the
  inscription procedure in national and European
  official lists, particularly in France
• The number of varieties included in the Italian
  Framework of sunflower variety trials has been
  increased from 11 in 1999 to 26 in 2003.

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High oleic varieties included in the National
framework trials on sunflower carried out in
Italy in 1999-2003
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Variety trials - results (1)

• New high oleic varieties together with high
  oleic varieties released some years ago and
  normal varieties (as checks) have been compared
  within a research framework in several sites in
  Central Italy. The following results have been
  obtained
• Several high oleic varieties showed higher
  achene yields per hectare than normal varieties

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Grain yield of sunflower (as percentages of the
overall mean)
High oleic varieties
Normal varieties
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Variety trials - results (2)

• New high oleic varieties together with high
  oleic varieties released some years ago and
  normal varieties (as checks) have been compared
  within a research framework, in several sites of
  Central Italy. The following results have been
  obtained
• Several high oleic varieties showed higher
  achene yields per hectare then traditional
  varieties
• As oil is the most important product of both food
  and non-food sunflower, varieties should be
  compared on the basis of oil yield per hectare
• When the above criteria is followed, the
  performance of new high - oleic varieties is
  even more markedly higher than those of normal
  genotypes

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Grain and oil yield of sunflower (as percentages
of the overall mean)
High oleic varieties
Normal varieties
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Variety trials - results (3)

• New high oleic varieties together with high
  oleic varieties released some years ago and
  normal varieties (as checks) have been compared
  within a research framework, in several sites of
  Central Italy. The following results have been
  obtained
• Several high oleic varieties showed higher
  achene yields per hectar then traditional
  varieties
• Oil is the most important product of both food
  and non-food sunflower. Thus, varieties should be
  compared on the basis of oil yield per hectare
• When the above criteria is followed, performances
  of new high - oleic varieties are even higher
  than those of traditional varieties
• Some varieties showed an oleic acid to total
  fatty acids ratio close to or higher than 90
  Also, this percentage was relatively stable,
  regardless of environment and years

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Oleic acid content(Average percentage mean and
variability)
High oleic varieties
Normal varieties
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Variety trials - conclusions

• Results of variety trials allow us to conclude
  that the new high oleic varieties are
  apparently better than those selected some years
  ago, in terms of both oleic acid yield and
  stability over different environments and years
• It is also extremely important to point out that
  several new high oleic varieties are
  genetically resistant to the races of downy
  mildew (Plasmopara helstedii) spread in Europe
• This very valuable characteristic ensures that
  sunflowers can be produced in short rotations,
  such as sunflower-wheat, which are very common
  in Italy

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General remarks

• Previously mentioned results seem to suggest that
  oleic acid yield and stability are positively
  influenced by the same cropping conditions and
  techniques which positively influence total
  achene and oil yield
• In the case of non-irrigated sunflower, these
  results may be found using lower input production
  methods such as
• low seed rates per hectare
• low N-fertilisation rates
• reduced tillage and low tillage depths

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• Indeed, experimental evidence is available which
  suggests that reduced tillage (subsoiling,
  minimum tillage) and low tillage depth
• does not reduce yield with respect to traditional
  deep ploughing
• reduces energy consumption to produce the crop
• reduces the amount of time required for seed bed
  preparation

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Different types of soil tillage for sunflower
grain yield, fuel consumption, working time
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• Therefore, it is possible to reduce the costs
  associated with tillage practices, which is the
  main component of sunflower production costs.
  This is particularly important to increase the
  profitability of non-food sunflower production.

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Conclusions

• An appropriate choice of variety is the most
  effective means to produce sunflower oil with
  high and stable oleic acid content
• High performance varieties are already available
  and further progress is expected through breeding
  techniques
• Non-food sunflowers can be produced efficiently
  using low input production methods
• In Mediterranean dryland conditions, the
  cultivation of sunflower for industrial purposes
  may take over the role so far played by sunflower
  for alimentary oil, as long as the crop is
  produced using sustainable farming methods.