Abstract
Abstract Root infection by the citrus nematode ( Tylenchulus semipenetrans Cobb) at population densities above the economic threshold caused altered patterns of root and shoot growth of 20-year-old ‘Washington’ Navel orange trees ( Citrus sinensis L. Osbeck) budded on Troyer citrange rootstock ( Poncirus trifoliata L. Raf. × C. sinensis ), compared with control trees protected from nematode infection by oxamyl (1.1 kg/ha/3 weeks) and permitted to recover from prior nematode infection. Nematode-infected trees initiated new roots every 4–6 weeks, beginning as early as midMarch through as late as mid-January. Each root flush was equal to or greater in magnitude (number of new roots per gram roots) than those observed from oxamyl-treated trees. Oxamyl significantly reduced the population of female nematodes. Oxamyl-treated trees produced 4 relatively small root flushes, typical of healthy trees and exhibited a net increase in root biomass; nematode-infected trees failed to increase root biomass despite repeated root initiation. Oxamyl-treated trees also produced more new shoots and exhibited a greater increase in length per shoot and mean number of leaves per unit shoot length than untreated trees. Measurements of the levels of available glucose, sucrose, and starch provided evidence that nematode-infected trees were carbohydrate depleted. Starch levels were typically 70% higher in the canopy and 96% higher in the roots of oxamyl-treated trees compared to untreated. Root initiation appears to be the first response of the trees penetrated by citrus nematode larvae; repeated root initiation in response to the many generations of larvae that hatch each year is probably a key factor contributing to the depletion of carbohydrate in nematode-infected trees.
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Claims 13
Claim · model-written summary
Nematode-infected orange trees initiated new roots every 4–6 weeks from midMarch through mid-January.
- Taxon
- Navel Orange
Citrus sinensist0 - Interactor
- Tylenchulus semipenetrans CobbTylenchulus semipenetranse1pathogen
- Outcome
- initiated new rootse0
- Value
- every 4–6 weekse0
- Qualifier
- beginning as early as midMarch through as late as mid-Januarye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nematode-infected trees initiated new roots every 4–6 weeks, beginning as early as midMarch through as late as mid-January.”
e1“citrus nematode ( Tylenchulus semipenetrans Cobb)”
t0“Navel Orange”
Claim · model-written summary
Each infected-tree root flush equaled or exceeded the new-root magnitude of oxamyl-treated trees.
- Taxon
- Navel OrangeCitrus sinensist0
- Interactor
- Tylenchulus semipenetrans CobbTylenchulus semipenetranse1pathogen
- Outcome
- number of new roots per gram rootse0
- Direction
- equal to or greatere0
- Comparator
- oxamyl-treated treese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Each root flush was equal to or greater in magnitude (number of new roots per gram roots) than those observed from oxamyl-treated trees.”
e1“citrus nematode ( Tylenchulus semipenetrans Cobb)”
t0“Navel Orange”
Claim · model-written summary
Oxamyl significantly reduced female citrus nematode populations.
- Taxon
- Navel OrangeCitrus sinensist0
- Treatment
- Oxamyle0
- Interactor
- Tylenchulus semipenetrans CobbTylenchulus semipenetranse1pathogen
- Outcome
- population of female nematodese0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Oxamyl significantly reduced the population of female nematodes.”
e1“citrus nematode ( Tylenchulus semipenetrans Cobb)”
t0“Navel Orange”
Claim · model-written summary
Oxamyl-treated trees produced four relatively small root flushes.
- Taxon
- Navel OrangeCitrus sinensist0
- Treatment
- Oxamyle0
- Outcome
- root flushese0
- Value
- 4e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Oxamyl-treated trees produced 4 relatively small root flushes, typical of healthy trees”
t0“Navel Orange”
Claim · model-written summary
Oxamyl-treated trees increased root biomass, whereas nematode-infected trees failed to increase it.
- Taxon
- Navel OrangeCitrus sinensist0
- Treatment
- Oxamyle1
- Interactor
- Tylenchulus semipenetrans CobbTylenchulus semipenetranse2pathogen
- Outcome
- root biomasse0
- Direction
- net increasee0
- Comparator
- nematode-infected treese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“exhibited a net increase in root biomass; nematode-infected trees failed to increase root biomass despite repeated root initiation.”
e1“Oxamyl-treated trees produced 4 relatively small root flushes”
e2“citrus nematode ( Tylenchulus semipenetrans Cobb)”
t0“Navel Orange”
Claim · model-written summary
Oxamyl-treated trees produced more new shoots than untreated trees.
- Taxon
- Navel OrangeCitrus sinensist0
- Treatment
- Oxamyle0
- Outcome
- new shootse0
- Direction
- moree0
- Comparator
- untreated treese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Oxamyl-treated trees also produced more new shoots and exhibited a greater increase in length per shoot and mean number of leaves per unit shoot length than untreated trees.”
t0“Navel Orange”
Claim · model-written summary
Oxamyl-treated trees had a greater increase in shoot length than untreated trees.
- Taxon
- Navel OrangeCitrus sinensist0
- Treatment
- Oxamyle0
- Outcome
- length per shoote0
- Direction
- greater increasee0
- Comparator
- untreated treese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Oxamyl-treated trees also produced more new shoots and exhibited a greater increase in length per shoot and mean number of leaves per unit shoot length than untreated trees.”
t0“Navel Orange”
Claim · model-written summary
Oxamyl-treated trees had more leaves per unit shoot length than untreated trees.
- Taxon
- Navel OrangeCitrus sinensist0
- Treatment
- Oxamyle0
- Outcome
- mean number of leaves per unit shoot lengthe0
- Direction
- greater increasee0
- Comparator
- untreated treese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Oxamyl-treated trees also produced more new shoots and exhibited a greater increase in length per shoot and mean number of leaves per unit shoot length than untreated trees.”
t0“Navel Orange”
Claim · model-written summary
Carbohydrate measurements indicated depletion in nematode-infected trees.
- Taxon
- Navel OrangeCitrus sinensist0
- Interactor
- Tylenchulus semipenetrans CobbTylenchulus semipenetranse1pathogen
- Outcome
- carbohydrate depletede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Measurements of the levels of available glucose, sucrose, and starch provided evidence that nematode-infected trees were carbohydrate depleted.”
e1“citrus nematode ( Tylenchulus semipenetrans Cobb)”
t0“Navel Orange”
Claim · model-written summary
Canopy starch was 70% higher in oxamyl-treated than untreated trees.
- Taxon
- Navel OrangeCitrus sinensist0
- Organ / stage
- canopye0
- Treatment
- oxamyle0
- Outcome
- Starch levelse0
- Direction
- highere0
- Value
- 70%e0
- Comparator
- untreatede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Starch levels were typically 70% higher in the canopy and 96% higher in the roots of oxamyl-treated trees compared to untreated.”
t0“Navel Orange”
Claim · model-written summary
Root starch was 96% higher in oxamyl-treated than untreated trees.
- Taxon
- Navel OrangeCitrus sinensist0
- Organ / stage
- rootse0
- Treatment
- oxamyle0
- Outcome
- Starch levelse0
- Direction
- highere0
- Value
- 96%e0
- Comparator
- untreatede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Starch levels were typically 70% higher in the canopy and 96% higher in the roots of oxamyl-treated trees compared to untreated.”
t0“Navel Orange”
Claim · model-written summary
Root initiation appears to be the first tree response to nematode larval penetration.
- Taxon
- Navel OrangeCitrus sinensist0
- Interactor
- citrus nematodeTylenchulus semipenetranse0pathogen
- Outcome
- Root initiatione0
- Qualifier
- first responsee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Root initiation appears to be the first response of the trees penetrated by citrus nematode larvae”
t0“Navel Orange”
Claim · model-written summary
Repeated root initiation probably contributes to carbohydrate depletion in nematode-infected trees.
- Taxon
- Navel OrangeCitrus sinensist0
- Interactor
- Tylenchulus semipenetrans CobbTylenchulus semipenetranse1pathogen
- Outcome
- depletion of carbohydratee0
- Qualifier
- repeated root initiatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“repeated root initiation in response to the many generations of larvae that hatch each year is probably a key factor contributing to the depletion of carbohydrate in nematode-infected trees.”
e1“citrus nematode ( Tylenchulus semipenetrans Cobb)”
t0“Navel Orange”
The same questions in other papers
oxamyl · yield · Citrus sinensis (sweet orange)Results agree
1 paper in the same direction as this paper
- positive
oxamyl · Tylenchulus semipenetrans · Citrus sinensis (sweet orange)Results agree
5 papers in the same direction as this paper
- positive
- positive
- positive
2 papers more in this group
See all 6 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.