Abstract
The effects of various P and Zn levels on iron nutrition of sunflower (Helianthus annuus L.c.v. Record) were studied in two separate experiments in nutrient solution under greenhouse conditions. In the first experiment, sunflower was grown in nutrient solutions containing four levels of P(1.5, 2.5, 3.5 and 4.5 mM/l) and three levels of Fe(0.25, 0.75, and 1.5 ppm) as FeCl3 or FeEDDHA. In the second experiment (following the first experiment), the treatments were three P levels (0.75, 1.50 and 3.00 mM/l), three Fe levels (0.25, 0.75 and 1.5 ppm) as FeEDDHA and three Zn levels (0.1, 0.2 and 0.4 ppm). The plants receiving Fe‐chelate, except for 0.25 ppm Fe, showed no symptoms of iron chlorosis. With inorganic Fe treatments, iron chlorosis appeared after 7–10 days depending on P level, but except for 0.25 ppm Fe which remained chlorotic, plants recovered completely within 3–4 days thereafter due to pH regulating mechanism of sunflower under iron stress condition. With both sources of Fe, chlorosis was associated with high P:Fe ratio. Increased P and Fe levels in nutrient solution resulted in general increases in the dry weights of roots and shoots. The Fe concentration of shoots, except in few instances, was not affected by P levels, indicating that the sunflower cultivar used in this experiment could utilize inorganic Fe as well as Fe‐chelate under our experimental conditions. Increasing P levels caused significant increases in Mn content of the shoots as 0.25 and 0.75 ppm inorganic Fe3+. Increased Fe levels increased shoot Mn content with inorganic Fe and decreased it with Fe‐chelate. The effects of P, Fe and Zn on sunflower indicated an antagonistic effect of Zn on 1.5 ppm Fe for all P levels. Increased Zn levels in nutrient solution generally increased Zn content of the shoots without having any marked effect on their Mn content.
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Claims 15
Claim · model-written summary
Sunflower plants receiving Fe-chelate showed no iron chlorosis symptoms, except at 0.25 ppm Fe, whereas inorganic Fe caused chlorosis.
- Taxon
- sunflower
Helianthus annuust0 - Treatment
- Fe‐chelatee0
- Outcome
- symptoms of iron chlorosise0
- Qualifier
- except for 0.25 ppm Fee0
- Comparator
- inorganic Fee1
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Iron nutrition of sunflower”
e0“The plants receiving Fe‐chelate, except for 0.25 ppm Fe, showed no symptoms of iron chlorosis”
e1“With inorganic Fe treatments, iron chlorosis appeared after 7–10 days depending on P level”
Claim · model-written summary
Inorganic Fe treatments caused iron chlorosis in sunflower after 7 to 10 days, depending on P level.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- inorganic Fee1
- Outcome
- iron chlorosise1
- Qualifier
- after 7–10 days depending on P levele1
- Comparator
- Fe‐chelatee0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Iron nutrition of sunflower”
e0“The plants receiving Fe‐chelate, except for 0.25 ppm Fe, showed no symptoms of iron chlorosis”
e1“With inorganic Fe treatments, iron chlorosis appeared after 7–10 days depending on P level”
Claim · model-written summary
The 0.25 ppm Fe treatment remained chlorotic in sunflower.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- 0.25 ppm Fee0
- Outcome
- remained chlorotice0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Iron nutrition of sunflower”
e0“except for 0.25 ppm Fe which remained chlorotic”
Claim · model-written summary
Sunflower plants under inorganic Fe, other than 0.25 ppm, recovered completely from chlorosis within 3 to 4 days.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- inorganic Fee0
- Outcome
- plants recovered completelye1
- Qualifier
- within 3–4 dayse1
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Iron nutrition of sunflower”
e0“With inorganic Fe treatments, iron chlorosis appeared after 7–10 days depending on P level”
e1“plants recovered completely within 3–4 days”
Claim · model-written summary
Sunflower recovery from iron chlorosis is attributed to a pH regulating mechanism.
- Taxon
- sunflowerHelianthus annuust0
- Outcome
- recovered completelye0
- Qualifier
- pH regulating mechanisme1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Iron nutrition of sunflower”
e0“plants recovered completely within 3–4 days”
e1“due to pH regulating mechanism of sunflower under iron stress condition”
Claim · model-written summary
Chlorosis was associated with a high P:Fe ratio.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- high P:Fe ratioe0
- Outcome
- chlorosise0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Iron nutrition of sunflower”
e0“chlorosis was associated with high P:Fe ratio”
Claim · model-written summary
Increased P and Fe levels increased dry weights of sunflower roots and shoots.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- Increased P and Fe levelse0
- Outcome
- dry weights of roots and shootse0
- Direction
- increasese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Iron nutrition of sunflower”
e0“Increased P and Fe levels in nutrient solution resulted in general increases in the dry weights of roots and shoots”
Claim · model-written summary
P levels did not affect the Fe concentration of sunflower shoots, except in few instances.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- P levelse0
- Outcome
- Fe concentration of shootse0
- Direction
- not affectede0
- Qualifier
- except in few instancese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Iron nutrition of sunflower”
e0“The Fe concentration of shoots, except in few instances, was not affected by P levels”
Claim · model-written summary
Sunflower cultivar could utilize inorganic Fe as well as Fe-chelate.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- inorganic Fee0
- Outcome
- utilizee0
- Comparator
- Fe‐chelatee0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Iron nutrition of sunflower”
e0“indicating that the sunflower cultivar used in this experiment could utilize inorganic Fe as well as Fe‐chelate”
Claim · model-written summary
Increasing P levels significantly increased shoot Mn content at 0.25 and 0.75 ppm inorganic Fe.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- P levelse0
- Outcome
- Mn content of the shootse0
- Direction
- increasese0
- Qualifier
- 0.25 and 0.75 ppm inorganic Fe3+e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Iron nutrition of sunflower”
e0“Increasing P levels caused significant increases in Mn content of the shoots as 0.25 and 0.75 ppm inorganic Fe3+”
Claim · model-written summary
Increased Fe levels increased shoot Mn content in sunflower with inorganic Fe.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- Increased Fe levelse0
- Outcome
- shoot Mn contente0
- Direction
- increasede0
- Qualifier
- with inorganic Fee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Iron nutrition of sunflower”
e0“Increased Fe levels increased shoot Mn content with inorganic Fe and decreased it with Fe‐chelate”
Claim · model-written summary
Increased Fe levels decreased shoot Mn content in sunflower with Fe-chelate.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- Increased Fe levelse0
- Outcome
- shoot Mn contente0
- Direction
- decreasede0
- Qualifier
- with Fe‐chelatee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Iron nutrition of sunflower”
e0“Increased Fe levels increased shoot Mn content with inorganic Fe and decreased it with Fe‐chelate”
Claim · model-written summary
Increased Zn levels generally increased shoot Zn content in sunflower.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- Increased Zn levelse0
- Outcome
- Zn content of the shootse0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Iron nutrition of sunflower”
e0“Increased Zn levels in nutrient solution generally increased Zn content of the shoots without having any marked effect on their Mn content”
Claim · model-written summary
Increased Zn levels had no marked effect on shoot Mn content in sunflower.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- Increased Zn levelse0
- Outcome
- Mn contente0
- Direction
- without having any marked effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Iron nutrition of sunflower”
e0“Increased Zn levels in nutrient solution generally increased Zn content of the shoots without having any marked effect on their Mn content”
Claim · model-written summary
Zn showed an antagonistic effect on 1.5 ppm Fe in sunflower at all P levels.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- Zne0
- Outcome
- antagonistic effecte0
- Qualifier
- for all P levelse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Iron nutrition of sunflower”
e0“The effects of P, Fe and Zn on sunflower indicated an antagonistic effect of Zn on 1.5 ppm Fe for all P levels”
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