Abstract
Citrus trees planted in alkaline soils typically show iron (Fe) deficiency chlorosis. Currently, Fe-EDDHA (ethylenediiminobis-2-hydroxyphenyl acetic acid) chelate is the most effective source of Fe for high pH soils. Iron humate (FeH), a by-product of the drinking water decolorization process, was compared with Fe-EDDHA for Fe deficiency correction on nonbearing `Ambersweet' orange and `Ruby Red' grapefruit Citrus paradisi Macf., and bearing `Hamlin' orange Citrus sinensis and `Flame' grapefruit trees, all on Swingle citrumelo rootstock, planted on high pH (>7.6) soils. Iron humate was applied under the tree canopy in spring at rates from 2 to 200 g Fe (nonbearing trees), or 22 to 352 g Fe (bearing trees) per tree per year. Application of FeH to nonbearing trees decreased twig dieback rating and increased flush growth, flush color rating, tree size, and leaf Fe concentration. Addition of urea or ammonium nitrate to FeH did not increase Fe availability. Iron amendments (22 g Fe per tree per year) increased fruit yield after the 1st year of application. Further increases in the rate of Fe, from 22 to 352 g Fe per tree per year as FeH, did not significantly increase tree growth, fruit yield, or fruit quality. This study demonstrated that FeH was an effective Fe source for citrus trees planted on alkaline soils.
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Claims 10
Claim · model-written summary
FeH decreased twig dieback in nonbearing citrus trees.
Not reportedComparator
Verbatim
e0“Application of FeH to nonbearing trees decreased twig dieback rating and increased flush growth, flush color rating, tree size, and leaf Fe concentration.”
t0“Orange and Grapefruit”
Claim · model-written summary
FeH increased flush growth, color and tree size in nonbearing citrus trees.
- Taxon
- Orange and Grapefruitt0
- Treatment
- FeHe0
- Outcome
- flush growth, flush color rating, tree sizee0
- Direction
- increasede0
Not reportedComparator
Verbatim
e0“Application of FeH to nonbearing trees decreased twig dieback rating and increased flush growth, flush color rating, tree size, and leaf Fe concentration.”
t0“Orange and Grapefruit”
Claim · model-written summary
FeH increased leaf Fe concentration in nonbearing citrus trees.
Not reportedComparator
Verbatim
e0“Application of FeH to nonbearing trees decreased twig dieback rating and increased flush growth, flush color rating, tree size, and leaf Fe concentration.”
t0“Orange and Grapefruit”
Claim · model-written summary
Adding urea to FeH did not increase iron availability.
Verbatim
e0“Addition of urea or ammonium nitrate to FeH did not increase Fe availability.”
t0“Orange and Grapefruit”
Claim · model-written summary
Adding ammonium nitrate to FeH did not increase iron availability.
Verbatim
e0“Addition of urea or ammonium nitrate to FeH did not increase Fe availability.”
t0“Orange and Grapefruit”
Claim · model-written summary
Iron amendments at 22 g Fe per tree per year increased fruit yield after one year.
- Taxon
- Orange and Grapefruitt0
- Treatment
- Iron amendments (22 g Fe per tree per year)e0
- Outcome
- fruit yielde0
- Direction
- increasede0
- Qualifier
- after the 1st year of applicatione0
Not reportedComparator
Verbatim
e0“Iron amendments (22 g Fe per tree per year) increased fruit yield after the 1st year of application.”
t0“Orange and Grapefruit”
Claim · model-written summary
Raising FeH from 22 to 352 g Fe per tree per year did not significantly increase tree growth.
- Taxon
- Orange and Grapefruitt0
- Treatment
- from 22 to 352 g Fe per tree per year as FeHe0
- Outcome
- tree growthe0
- Direction
- did not significantly increasee0
Not reportedComparator
Verbatim
e0“Further increases in the rate of Fe, from 22 to 352 g Fe per tree per year as FeH, did not significantly increase tree growth, fruit yield, or fruit quality.”
t0“Orange and Grapefruit”
Claim · model-written summary
Raising FeH from 22 to 352 g Fe per tree per year did not significantly increase fruit yield.
- Taxon
- Orange and Grapefruitt0
- Treatment
- from 22 to 352 g Fe per tree per year as FeHe0
- Outcome
- fruit yielde0
- Direction
- did not significantly increasee0
Not reportedComparator
Verbatim
e0“Further increases in the rate of Fe, from 22 to 352 g Fe per tree per year as FeH, did not significantly increase tree growth, fruit yield, or fruit quality.”
t0“Orange and Grapefruit”
Claim · model-written summary
Raising FeH from 22 to 352 g Fe per tree per year did not significantly increase fruit quality.
- Taxon
- Orange and Grapefruitt0
- Treatment
- from 22 to 352 g Fe per tree per year as FeHe0
- Outcome
- fruit qualitye0
- Direction
- did not significantly increasee0
Not reportedComparator
Verbatim
e0“Further increases in the rate of Fe, from 22 to 352 g Fe per tree per year as FeH, did not significantly increase tree growth, fruit yield, or fruit quality.”
t0“Orange and Grapefruit”
Claim · model-written summary
FeH was an effective iron source for citrus trees in alkaline soil.
CitrusOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This study demonstrated that FeH was an effective Fe source for citrus trees planted on alkaline soils.”
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See all 11 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.