Abstract
An 8-year-old, stagnating black walnut (Juglans nigra L.) plantation near Parkhill, Middlesex County, Ontario received applications of 6.7 kg/ha of active simazine in April of three successive years with or without applications of 100 and 200 kg/ha of elemental N. Elimination of 90% of the herbaceous competition increased 4-year diameter and height growth of the walnut trees by 153 and 222%, respectively. Fertilization with weed control further increased diameter and height growth. The response to N, however, was not proportional to the dosage of fertilizer applied and was not significantly greater than that obtained by weed control only. All treatments greatly increased the N content of the walnut leaves. Foliar N was still higher in all treated plots than in the control 4 years after treatment. Competition for N from broadleaf weeds and grasses is a major cause of growth stagnation in young black walnut plantations.
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Claims 8
Claim · model-written summary
Removing herbaceous competition increased four-year walnut diameter growth by 153%.
- Taxon
- walnut treese0
- Treatment
- Elimination of 90% of the herbaceous competitione0
- Interactor
- herbaceous competitione0weed
- Outcome
- diametere0
- Direction
- increasede0
- Value
- 153e0
Not reportedComparator
Verbatim
e0“Elimination of 90% of the herbaceous competition increased 4-year diameter and height growth of the walnut trees by 153 and 222%, respectively”
Claim · model-written summary
Removing herbaceous competition increased four-year walnut height growth by 222%.
- Taxon
- walnut treese0
- Treatment
- Elimination of 90% of the herbaceous competitione0
- Interactor
- herbaceous competitione0weed
- Outcome
- height growthe0
- Direction
- increasede0
- Value
- 222%e0
Not reportedComparator
Verbatim
e0“Elimination of 90% of the herbaceous competition increased 4-year diameter and height growth of the walnut trees by 153 and 222%, respectively”
Claim · model-written summary
Fertilization combined with weed control further increased walnut diameter and height growth.
- Taxon
- black walnut
Juglans nigrat0 - Treatment
- Fertilization with weed controle0
- Outcome
- diameter and height growthe0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Fertilization with weed control further increased diameter and height growth”
t0“Black Walnut”
Claim · model-written summary
Nitrogen response did not scale with fertilizer dose.
- Taxon
- black walnutJuglans nigrat0
- Treatment
- dosage of fertilizer appliede0
- Outcome
- response to Ne0
- Direction
- not proportionale0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The response to N, however, was not proportional to the dosage of fertilizer applied”
t0“Black Walnut”
Claim · model-written summary
Fertilization did not improve growth significantly beyond weed control alone.
- Taxon
- black walnutJuglans nigrat0
- Treatment
- Fertilizatione1
- Outcome
- greatere0
- Direction
- not significantly greatere0
- Comparator
- weed control onlye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“was not significantly greater than that obtained by weed control only”
e1“Fertilization with weed control further increased diameter and height growth”
t0“Black Walnut”
Claim · model-written summary
All treatments raised walnut leaf nitrogen content substantially.
Not reportedComparator
Verbatim
e0“All treatments greatly increased the N content of the walnut leaves”
Claim · model-written summary
Treated plots retained higher foliar nitrogen than controls four years after treatment.
- Taxon
- black walnutJuglans nigrat0
- Outcome
- Foliar Ne0
- Direction
- highere0
- Qualifier
- 4 years after treatmente0
- Comparator
- the controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Foliar N was still higher in all treated plots than in the control 4 years after treatment”
t0“Black Walnut”
Claim · model-written summary
The authors identify nitrogen competition from broadleaf weeds and grasses as a major cause of walnut growth stagnation.
- Taxon
- black walnutJuglans nigrae0
- Interactor
- broadleaf weeds and grassese0weed
- Compound
- Ne0
- Outcome
- growth stagnatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Competition for N from broadleaf weeds and grasses is a major cause of growth stagnation in young black walnut plantations”
The same questions in other papers
herbicide · growth · Juglans nigra (black walnut)Results agree
1 paper in the same direction as this paper
- positive
fertilization · growth · Juglans nigra (black walnut)Results agree
3 papers in the same direction as this paper
- positive
- positive
- positive
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.