Abstract
Methods for Zn fertilization of `Hass' avocado ( Persea americana Mill.) trees were evaluated in a 2-year field experiment on a commercial orchard located on a calcareous soil (pH 7.8) in Ventura County, Calif. The fertilization methods included soil- or irrigation-applied ZnSO 4 ; irrigation-applied Zn chelate (Zn-EDTA); trunk injection of Zn(NO 3 ) 2 , and foliar applications of ZnSO 4 , ZnO, or Zn metalosate. Other experiments evaluated the influence of various surfactants on the Zn contents of leaves treated with foliar-applied materials and on the retention and translocation of radiolabeled 65 ZnSO 4 and 65 Zn metalosate after application to the leaf surface. In the field experiment, tree responses to fertilization with soil-applied materials were affected significantly by their initial status, such that only trees having <50 μg·g –1 had significant increases in foliar Zn contents after fertilization. Among the three soil and irrigation treatments, ZnSO 4 applied at 3.2 kg ZnSO 4 per tree either as a quarterly irrigation or annually as a soil application was the most effective and increased leaf tissue Zn concentrations to 75 and 90 μg·g –1 , respectively. Foliar-applied ZnSO 4 , ZnO, and Zn metalosate with Zn at 5.4, 0.8, and 0.9 g·liter –1 , respectively, also resulted in increased leaf Zn concentrations. However, experiments with 65 Zn applied to leaves of greenhouse seedlings showed that <1% of Zn applied as ZnSO 4 or Zn metalosate was actually taken up by the leaf tissue and that there was little translocation of Zn into leaf parenchyma tissue adjacent to the application spots or into the leaves above or below the treated leaves. Given these problems with foliar Zn, fertilization using soil- or irrigation-applied ZnSO 4 may provide the most reliable method for correction of Zn deficiency in avocado on calcareous soils.
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Claims 8
Claim · model-written summary
In avocado trees, only those with initial foliar Zn below 50 μg/g had significant increases in foliar Zn after soil-applied fertilization.
- Taxon
- Avocado Trees
Persea americanat0 - Treatment
- fertilizatione0
- Outcome
- foliar Zn contentse0
- Direction
- increasese0
- Qualifier
- only trees having <50 μg·g –1e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Zinc Fertilization of Avocado Trees”
e0“only trees having <50 μg·g –1 had significant increases in foliar Zn contents after fertilization”
Claim · model-written summary
Among the soil and irrigation treatments, ZnSO4 at 3.2 kg per tree applied quarterly by irrigation or annually to soil was most effective, raising leaf Zn to 75 and 90 μg/g respectively.
- Taxon
- Avocado TreesPersea americanat0
- Treatment
- ZnSO 4 applied at 3.2 kg ZnSO 4 per treee0
- Outcome
- leaf tissue Zn concentrationse0
- Direction
- increasede0
- Value
- 75 and 90 μg·g –1e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Zinc Fertilization of Avocado Trees”
e0“ZnSO 4 applied at 3.2 kg ZnSO 4 per tree either as a quarterly irrigation or annually as a soil application was the most effective and increased leaf tissue Zn concentrations to 75 and 90 μg·g –1 , respectively”
Claim · model-written summary
Foliar-applied ZnSO4 (Zn at 5.4 g/L) increased leaf Zn concentrations.
- Taxon
- Avocado TreesPersea americanat0
- Treatment
- Foliar-applied ZnSO 4e0
- Outcome
- leaf Zn concentrationse0
- Direction
- increasede0
- Qualifier
- Zn at 5.4, 0.8, and 0.9 g·liter –1 , respectivelye0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Zinc Fertilization of Avocado Trees”
e0“Foliar-applied ZnSO 4 , ZnO, and Zn metalosate with Zn at 5.4, 0.8, and 0.9 g·liter –1 , respectively, also resulted in increased leaf Zn concentrations”
Claim · model-written summary
Foliar-applied ZnO (Zn at 0.8 g/L) increased leaf Zn concentrations.
- Taxon
- Avocado TreesPersea americanat0
- Treatment
- ZnOe0
- Outcome
- leaf Zn concentrationse0
- Direction
- increasede0
- Qualifier
- Zn at 5.4, 0.8, and 0.9 g·liter –1 , respectivelye0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Zinc Fertilization of Avocado Trees”
e0“Foliar-applied ZnSO 4 , ZnO, and Zn metalosate with Zn at 5.4, 0.8, and 0.9 g·liter –1 , respectively, also resulted in increased leaf Zn concentrations”
Claim · model-written summary
Foliar-applied Zn metalosate (Zn at 0.9 g/L) increased leaf Zn concentrations.
- Taxon
- Avocado TreesPersea americanat0
- Treatment
- Zn metalosatee0
- Outcome
- leaf Zn concentrationse0
- Direction
- increasede0
- Qualifier
- Zn at 5.4, 0.8, and 0.9 g·liter –1 , respectivelye0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Zinc Fertilization of Avocado Trees”
e0“Foliar-applied ZnSO 4 , ZnO, and Zn metalosate with Zn at 5.4, 0.8, and 0.9 g·liter –1 , respectively, also resulted in increased leaf Zn concentrations”
Claim · model-written summary
In greenhouse seedlings, less than 1% of leaf-applied Zn from ZnSO4 or Zn metalosate was taken up by the leaf tissue.
- Taxon
- Avocado TreesPersea americanat0
- Treatment
- Zn applied as ZnSO 4 or Zn metalosatee0
- Outcome
- taken up by the leaf tissuee0
- Value
- <1%e0
- Setting
- greenhouse seedlingse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Zinc Fertilization of Avocado Trees”
e0“experiments with 65 Zn applied to leaves of greenhouse seedlings showed that <1% of Zn applied as ZnSO 4 or Zn metalosate was actually taken up by the leaf tissue”
Claim · model-written summary
There was little translocation of leaf-applied Zn into adjacent leaf parenchyma or into leaves above or below the treated leaves.
- Taxon
- Avocado TreesPersea americanat0
- Outcome
- translocation of Zne0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Zinc Fertilization of Avocado Trees”
e0“there was little translocation of Zn into leaf parenchyma tissue adjacent to the application spots or into the leaves above or below the treated leaves”
Claim · model-written summary
The authors suggest soil- or irrigation-applied ZnSO4 may be the most reliable way to correct Zn deficiency in avocado on calcareous soils.
- Taxon
- avocadoPersea americanae0
- Outcome
- correction of Zn deficiencye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“fertilization using soil- or irrigation-applied ZnSO 4 may provide the most reliable method for correction of Zn deficiency in avocado on calcareous soils”
The same questions in other papers
zinc atom · nutrient: content · Persea americana (avocado)Positive and negative results
1 paper in the same direction as this paper · 1 reporting no difference from an alternative
- positive
- no effect
application · nutrient: content · Persea americana (avocado)Positive and negative results
1 paper in the same direction as this paper · 2 in the opposite direction
- no effect
- negative
- positive
fertilization · nutrient: content · Persea americana (avocado)Positive and negative results
3 papers in the same direction as this paper · 1 in the opposite direction
- no effect
- positive
- positive
1 paper more in this group
See all 5 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.