Effects of water stress at different development stages on yield and water
productivity of winter and summer safﬂower (Carthamus tinctorius L.)
, E. Gocmen
, E. Gezer
, C. Pasa
, F. Konukcu
Namik Kemal University, Agricultural Faculty, Agricultural Construction and Irrigation Department, TR-59030 Tekirdag, Turkey
Namik Kemal University, Agricultural Faculty, Field Crops Department, TR-59030 Tekirdag, Turkey
Presently, effect of global climate change, whose impact is
increasingly experienced year by year, is forecasted to be felt more
and more in Turkey as well in its Thrace Region placed in
Mediterranean Basin (Anonymous, 2007).
Probable agricultural drought due to this global climate change
necessitates inevitably that water should be used effectively in
irrigated agriculture to increase and sustain productivity. Deﬁcit
irrigation is a way of using water effectively.
In crop production, instead of achieving maximum yield from a
unit area by full irrigation, optimum irrigation number or amount
of irrigation water may be limited by allowing small yield
decreases from a unit area but more area is irrigated with the
same amount of irrigation water and water productivity can be
optimized within the concept of deﬁcit irrigation (Allen et al.,
1998; Fereres and Soriano, 2006).
Due to intensive population, increasing food requirement and
limited water resources both in Turkey and in the Thrace Region in
the Northwest of Turkey, deﬁcit irrigation is inevitable.
Safﬂower, which is subsidised by the government in order to
cover the cooking oil shortages in Turkey, has recently placed in the
crop rotation of the Thrace Region in increasing ratio. Therefore,
knowledge on the irrigation schedule and water use efﬁciency of
safﬂower under deﬁcit irrigation condition becomes more
important. This is because all ﬁeld crops response differently in
different phonological stages to changing water status of the soil
under deﬁcit irrigation, which means that plants are more
sensitive to water deﬁcit at one or more stages than at the other
stages. For example, these sensitive stages are during ﬂowering
and boll formation stages in cotton, during vegetative growth of
soybean, ﬂowering and grain ﬁlling stages of wheat, vegetative and
yielding stages of sunﬂower and sugar beet (Kirda, 2002).
Available limited researches in Turkey and around the world on
safﬂower production under irrigated conditions revealed that it
was a sensitive crop to water (Quiroga et al., 2001; Bassil and
Kaffka, 2002a,b) and moderately tolerant to salinity. Kar et al.
(2007) investigated the total water use efﬁciency of safﬂower in a
Agricultural Water Management 96 (2009) 1429–1434
Received 20 February 2008
Accepted 1 April 2009
Available online 23 May 2009
Yield response to water
A ﬁeld study was carried out to determine the effects of water stress imposed at different development
stages on grain yield, seasonal evapotranspiration, crop–water relationships, yield response to water and
water use efﬁciency of safﬂower (Carthamus tinctorius L.) for winter and summer sowing. The ﬁeld trials
were conducted on a loam Entisol soil in Thrace Region in Turkey, using Dincer, the most popular
safﬂower variety in the research area. A randomised complete block design with three replications was
used. Three known growth stages of the plant were considered and a total of 8 (including rainfed)
irrigation treatments were applied. The effect of irrigation or water stress at any stage of development on
grain yield per hectare and 1000 kernel weight, was evaluated. Results of this study showed that
safﬂower was signiﬁcantly affected by water shortage in the soil proﬁle due to omitted irrigation during
the sensitive vegetative stage. The highest yield was observed in the fully irrigated control and was
higher for winter sowing than for summer sowing. Evapotranspiration calculated for non-stressed
production was 728 and 673 mm for winter and summer sowing, respectively. Safﬂower grain yield of
the fully irrigated treatments was 4.05 and 3.74 t ha
for winter and summer season, respectively. The
seasonal yield response factor was 0.97 and 0.81 for winter and summer sowing, respectively. The
highest total water use efﬁciency was obtained in the treatment irrigated only at vegetative stage while
the lowest value was observed when the crop was irrigated only at yield stage. As conclusions: (i) winter
sowing is suggested; (ii) if deﬁcit irrigation is to apply at only one or two stages, Y stage or Y and F stages
should be omitted, respectively.
ß 2009 Elsevier B.V. All rights reserved.
* Corresponding author. Tel.: +90 282 2931442; fax: +90 282 2931489.
E-mail address: email@example.com (A. Istanbulluoglu).
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0378-3774/$ – see front matter ß 2009 Elsevier B.V. All rights reserved.