Abstract
Abstract Sunflower ( Helianthus annuus L.) is both tolerant to water deficits and capable of bearing high yield in response to irrigation inputs. In both situations, knowledge of the seasonal distribution of water uptake and the quantification of water extracted in deeper soil layers are required for irrigation scheduling. In a 2‐yr field study in southern Italy, we determined water consumption in relation to seed yield of ‘Romsun HS90’ sunflower with early (spring; mid‐April) and late (summer; mid‐June) sowing dates under five irrigation regimes: a rainfed control; periodic replacement of calculated crop evapotranspiration (a meteorological approach); and one, two, or three irrigation applications at selected growth stages assumed critical for yield expression (a phenological approach). Spring‐sown crops provided significantly higher yields (3.15 vs. 1.75 t ha −1 ). Irrigation was necessary to achieve high production, especially for the summer crop. Three waterings gave best results in 1989 only. The treatment providing two waterings always showed similar yield and more efficient use of water with respect to the treatment irrigated according to the meteorological approach and performed better than the single irrigation. The ratio between actual and reference crop evapotranspiration was 20% higher in the period between R1 and R6 for the summer crop and 30% higher for the spring crop, with respect to the adopted crop coefficients ( K c ). All the yield components were positively affected by irrigation; the most important one was found to be the diameter of calathide. Oil concentration in the achenes was always lower in the summer crop and increased when adequate irrigation was provided, especially in the grain‐filling stage.
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Claims 11
Claim · model-written summary
Spring sowing produced significantly higher seed yield than summer sowing.
- Taxon
- Sunflower
Helianthus annuust0 - Treatment
- Spring‐sowne0
- Outcome
- yieldse0
- Direction
- highere0
- Value
- 3.15 vs. 1.75 t ha −1e0
- Comparator
- summert0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Spring‐sown crops provided significantly higher yields (3.15 vs. 1.75 t ha −1 )”
t0“Sunflower Sown in Spring and Summer”
Claim · model-written summary
Irrigation was needed for high production, especially in summer crops.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- Irrigatione0
- Outcome
- high productione0
- Direction
- highe0
- Qualifier
- especially for the summer crope0
- Comparator
- rainfed controle1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Irrigation was necessary to achieve high production, especially for the summer crop”
t0“Sunflower Sown in Spring and Summer”
e1“a rainfed control; periodic replacement of calculated crop evapotranspiration”
Claim · model-written summary
Three waterings gave the best results only in 1989.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- Three wateringse0
- Outcome
- best resultse0
- Direction
- beste0
- Qualifier
- in 1989 onlye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Three waterings gave best results in 1989 only”
t0“Sunflower Sown in Spring and Summer”
Claim · model-written summary
Two waterings yielded similarly to meteorological irrigation while using water more efficiently.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- two wateringse0
- Outcome
- yield and more efficient use of watere0
- Direction
- similare0
- Comparator
- the treatment irrigated according to the meteorological approache0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The treatment providing two waterings always showed similar yield and more efficient use of water with respect to the treatment irrigated according to the meteorological approach”
t0“Sunflower Sown in Spring and Summer”
Claim · model-written summary
Two waterings performed better than one irrigation.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- two wateringse1
- Outcome
- performed bettere0
- Direction
- bettere0
- Comparator
- the single irrigatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“performed better than the single irrigation”
t0“Sunflower Sown in Spring and Summer”
e1“The treatment providing two waterings always showed similar yield”
Claim · model-written summary
The actual-to-reference evapotranspiration ratio was 20% higher between R1 and R6 for summer crops than adopted coefficients.
- Taxon
- SunflowerHelianthus annuust0
- Outcome
- ratio between actual and reference crop evapotranspiratione0
- Direction
- highere0
- Value
- 20%e0
- Qualifier
- summer crope0
- Comparator
- adopted crop coefficients ( K c )e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The ratio between actual and reference crop evapotranspiration was 20% higher in the period between R1 and R6 for the summer crop and 30% higher for the spring crop, with respect to the adopted crop coefficients ( K c )”
t0“Sunflower Sown in Spring and Summer”
Claim · model-written summary
The ratio was 30% higher for spring crops than adopted coefficients.
- Taxon
- SunflowerHelianthus annuust0
- Outcome
- ratio between actual and reference crop evapotranspiratione0
- Direction
- highere0
- Value
- 30%e0
- Qualifier
- spring crope0
- Comparator
- adopted crop coefficients ( K c )e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The ratio between actual and reference crop evapotranspiration was 20% higher in the period between R1 and R6 for the summer crop and 30% higher for the spring crop, with respect to the adopted crop coefficients ( K c )”
t0“Sunflower Sown in Spring and Summer”
Claim · model-written summary
Irrigation positively affected all yield components.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- irrigatione0
- Outcome
- yield componentse0
- Direction
- positively affectede0
- Comparator
- rainfed controle1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“All the yield components were positively affected by irrigation”
t0“Sunflower Sown in Spring and Summer”
e1“a rainfed control; periodic replacement of calculated crop evapotranspiration”
Claim · model-written summary
Calathide diameter was the most important yield component.
- Taxon
- SunflowerHelianthus annuust0
- Outcome
- diameter of calathidee0
- Direction
- most importante0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the most important one was found to be the diameter of calathide”
t0“Sunflower Sown in Spring and Summer”
Claim · model-written summary
Achene oil concentration was lower in summer crops.
- Taxon
- SunflowerHelianthus annuust0
- Organ / stage
- achenese0
- Outcome
- Oil concentratione0
- Direction
- lowere0
- Qualifier
- summer crope0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Oil concentration in the achenes was always lower in the summer crop”
t0“Sunflower Sown in Spring and Summer”
Claim · model-written summary
Adequate irrigation increased achene oil concentration, especially during grain filling.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- adequate irrigatione0
- Outcome
- Oil concentratione1
- Direction
- increasede0
- Qualifier
- especially in the grain‐filling stagee0
- Comparator
- rainfed controle2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increased when adequate irrigation was provided, especially in the grain‐filling stage”
t0“Sunflower Sown in Spring and Summer”
e1“Oil concentration in the achenes was always lower in the summer crop”
e2“a rainfed control; periodic replacement of calculated crop evapotranspiration”
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