Abstract
A pot experiment was established to determine the influence of rate of superphosphate (applied at planting only) on the growth and fruiting responses of young apple trees (Jonathan/3428) in four successive growing seasons. Increasing the rate of application of superphosphate stimulated tree growth, fruit set and yield over much of the range tested. A critical leaf phosphorus value of 0.32 % in mid-shoot leaves in midsummer is suggested for newly planted apple trees. Phosphate-deficient trees showed delayed bud burst and a retarded rate of development of a reduced number of vegetative and floral meristems. The pronounced effect of phosphorus level on percentage fruit set was also at least partially attributable to its effect on the rate of flower cluster emergence since delayed emergence reduced the opportunity for cross-pollination and fruit set. Fruit from phosphorus-deficient trees contained fewer but larger cells than fruit from non-deficient trees. These results are consistent with the hypothesis that phosphorus level is an important regulator of the meristematic activity of apple tree tissue. Leaves and fruit on phosphorus-deficient trees showed comparatively early senescence. It is suggested that retarded bud development on deficient trees in spring and early senescence of deficient tissues in autumn could result from reduced cytokinin production by deficient trees. Leaf analysis was superior to fruit analysis as an index of the phosphorus status of apple trees. Fruit phosphorus values tended to be constant with time for a given treatment, but leaf phosphorus values declined with time and progressively more of the trees in the low phosphorus treatments developed visual symptoms of phosphorus deficiency. Analysis of soil each year proved of little value as a predictor of the phosphorus status of the trees, since deficiency symptoms were seen on trees grown in soil containing over 1000 ppm phosphorus. Magnesium deficiency symptoms developed on trees in the high phosphorus treatments, and the possible reason for this is briefly discussed.
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Claims 14
Claim · model-written summary
Increasing superphosphate stimulated tree growth, fruit set and yield over much of the range.
- Taxon
- apple trees
Malus domesticae1 - Material
- Jonathan/3428e1
- Treatment
- Increasing the rate of application of superphosphatee0
- Outcome
- tree growth, fruit set and yielde0
- Direction
- stimulatede0
- Qualifier
- over much of the range testede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Increasing the rate of application of superphosphate stimulated tree growth, fruit set and yield over much of the range tested”
e1“young apple trees (Jonathan/3428) in four successive growing seasons”
Claim · model-written summary
The authors suggest a critical midsummer leaf phosphorus value of 0.32% for newly planted apple trees.
- Taxon
- apple treesMalus domesticae0
- Organ / stage
- mid-shoot leavese0
- Outcome
- critical leaf phosphorus valuee0
- Value
- 0.32 %e0
- Qualifier
- in midsummere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A critical leaf phosphorus value of 0.32 % in mid-shoot leaves in midsummer is suggested for newly planted apple trees”
Claim · model-written summary
Phosphate-deficient trees had delayed bud burst.
- Taxon
- apple treesMalus domesticae1
- Treatment
- Phosphate-deficiente0
- Outcome
- delayed bud burste0
- Direction
- delayede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Phosphate-deficient trees showed delayed bud burst”
e1“young apple trees (Jonathan/3428) in four successive growing seasons”
Claim · model-written summary
Phosphate-deficient trees had retarded development of fewer vegetative and floral meristems.
- Taxon
- apple treesMalus domesticae1
- Treatment
- Phosphate-deficiente0
- Outcome
- rate of development of a reduced number of vegetative and floral meristemse0
- Direction
- retardede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Phosphate-deficient trees showed delayed bud burst and a retarded rate of development of a reduced number of vegetative and floral meristems”
e1“young apple trees (Jonathan/3428) in four successive growing seasons”
Claim · model-written summary
Delayed flower cluster emergence reduced opportunity for cross-pollination and fruit set.
- Taxon
- apple treesMalus domesticae1
- Outcome
- opportunity for cross-pollination and fruit sete0
- Qualifier
- delayed emergencee0
Not reportedOrgan / stage
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“delayed emergence reduced the opportunity for cross-pollination and fruit set”
e1“young apple trees (Jonathan/3428) in four successive growing seasons”
Claim · model-written summary
Fruit from phosphorus-deficient trees contained fewer cells than non-deficient fruit.
- Taxon
- apple treesMalus domesticae1
- Organ / stage
- Fruite0
- Treatment
- phosphorus-deficiente0
- Outcome
- cellse0
- Direction
- fewere0
- Comparator
- non-deficient treese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Fruit from phosphorus-deficient trees contained fewer but larger cells than fruit from non-deficient trees”
e1“young apple trees (Jonathan/3428) in four successive growing seasons”
Claim · model-written summary
Fruit from phosphorus-deficient trees contained larger cells than non-deficient fruit.
- Taxon
- apple treesMalus domesticae1
- Organ / stage
- Fruite0
- Treatment
- phosphorus-deficiente0
- Outcome
- cellse0
- Direction
- largere0
- Comparator
- non-deficient treese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Fruit from phosphorus-deficient trees contained fewer but larger cells than fruit from non-deficient trees”
e1“young apple trees (Jonathan/3428) in four successive growing seasons”
Claim · model-written summary
Phosphorus-deficient leaves and fruit senesced comparatively early.
- Taxon
- apple treesMalus domesticae1
- Organ / stage
- Leaves and fruite0
- Treatment
- phosphorus-deficiente0
- Outcome
- senescencee0
- Direction
- comparatively earlye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Leaves and fruit on phosphorus-deficient trees showed comparatively early senescence”
e1“young apple trees (Jonathan/3428) in four successive growing seasons”
Claim · model-written summary
Leaf analysis was superior to fruit analysis as an index of tree phosphorus status.
- Taxon
- apple treesMalus domesticae0
- Outcome
- phosphorus statuse0
- Direction
- superiore0
- Comparator
- fruit analysise0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Leaf analysis was superior to fruit analysis as an index of the phosphorus status of apple trees”
Claim · model-written summary
Fruit phosphorus values tended to remain constant over time for a given treatment.
- Taxon
- apple treesMalus domesticae1
- Outcome
- Fruit phosphorus valuese0
- Direction
- constante0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Fruit phosphorus values tended to be constant with time for a given treatment”
e1“young apple trees (Jonathan/3428) in four successive growing seasons”
Claim · model-written summary
Leaf phosphorus values declined with time.
- Taxon
- apple treesMalus domesticae1
- Outcome
- leaf phosphorus valuese0
- Direction
- declinede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“leaf phosphorus values declined with time”
e1“young apple trees (Jonathan/3428) in four successive growing seasons”
Claim · model-written summary
More low-phosphorus trees developed visible phosphorus deficiency symptoms over time.
- Taxon
- apple treesMalus domesticae1
- Treatment
- low phosphorus treatmentse0
- Outcome
- visual symptoms of phosphorus deficiencye0
- Direction
- progressively moree0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“progressively more of the trees in the low phosphorus treatments developed visual symptoms of phosphorus deficiency”
e1“young apple trees (Jonathan/3428) in four successive growing seasons”
Claim · model-written summary
Soil analysis had little predictive value for tree phosphorus status, despite symptoms above 1000 ppm soil phosphorus.
- Taxon
- apple treesMalus domesticae1
- Outcome
- predictor of the phosphorus statuse0
- Value
- over 1000 ppm phosphoruse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Analysis of soil each year proved of little value as a predictor of the phosphorus status of the trees, since deficiency symptoms were seen on trees grown in soil containing over 1000 ppm phosphorus”
e1“young apple trees (Jonathan/3428) in four successive growing seasons”
Claim · model-written summary
High-phosphorus trees developed magnesium deficiency symptoms.
- Taxon
- apple treesMalus domesticae1
- Treatment
- high phosphorus treatmentse0
- Outcome
- Magnesium deficiency symptomse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Magnesium deficiency symptoms developed on trees in the high phosphorus treatments”
e1“young apple trees (Jonathan/3428) in four successive growing seasons”
The same questions in other papers
phosphorus · yield · Malus domestica (apple)Results differ
8 papers in the same direction as this paper · 3 in the opposite direction
- positive
- no effect
- no effect
8 papers more in this group
See all 12 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.