Abstract
The effects of nitrogen (N) rate and timing on need for fungicide application in winter wheat ( Triticum aestivum ) were investigated in 3 years of field experiments on loamy sand soils in Denmark. A two-factor completely randomized experimental design was used, comprising seven combinations of different N fertilizer rates and application times, and five doses of fungicide (co-formulation propiconazole and fenpropimorph). Two different varieties of winter wheat with high susceptibility to powdery mildew ( Blumeria graminis ) were used, Florida in the first season and Pepital in the last two seasons. The severity of powdery mildew and septoria leaf spot (mainly Septoria tritici ) varied between seasons from slight to moderate with powdery mildew dominating in the first season and septoria leaf spot in the last season. The severity of both powdery mildew and septoria leaf spot assessed as the Area Under the Disease Progress Curve (AUDPC) was increased by application of N in all years, and more so by early applied N. Grain yields increased with increasing N rate and fungicide dose. However, the observed grain yields did not reveal any N×fungicide interactions. Regression models were therefore fitted, relating grain yield to rate and timing of N fertilizer and to AUDPC of powdery mildew and septoria leaf spot, and relating AUDPC to rate and timing of N fertilizer and to fungicide dose. They demonstrated that septoria leaf spot had a considerably higher impact on grain yield than mildew. The optimal fungicide dose and N rate were defined as those giving the highest economic return. The regression models were used to estimate the effect of N rate and timing on optimal fungicide dose, and the effect of fungicide application on optimal N rate. The optimal fungicide dose increased almost linearly with N rate above a minimum N rate, but with a large dependency on price relations. Early applied N caused a higher demand for disease control. The fungicide applications in the model were mainly driven by the need to control septoria leaf spot, whereas powdery mildew gave a poor net return for control. The estimated optimal N fertilizer rate for untreated diseased crops was 60 kg N/ha lower than for crops without disease. The use of fungicides with an efficacy twice that of the EBI-fungicides used in this experiment would increase the optimal N rate by c . 20 kg N/ha.
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Claims 8
Claim · model-written summary
Nitrogen application increased the severity of powdery mildew and septoria leaf spot in winter wheat, more so when applied early.
- Taxon
- winter wheat
Triticum aestivume0 - Treatment
- application of Ne1
- Interactor
- powdery mildewe1pathogen
- Second interactor
- septoria leaf spote1pathogen
- Outcome
- severity of both powdery mildew and septoria leaf spote1
- Direction
- increasede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The effects of nitrogen (N) rate and timing on need for fungicide application in winter wheat ( Triticum aestivum ) were investigated”
e1“The severity of both powdery mildew and septoria leaf spot assessed as the Area Under the Disease Progress Curve (AUDPC) was increased by application of N in all years, and more so by early applied N”
Claim · model-written summary
Grain yields increased with increasing nitrogen rate and fungicide dose in winter wheat.
- Taxon
- winter wheatTriticum aestivume0
- Treatment
- increasing N rate and fungicide dosee2
- Outcome
- Grain yieldse2
- Direction
- increasede2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The effects of nitrogen (N) rate and timing on need for fungicide application in winter wheat ( Triticum aestivum ) were investigated”
e2“Grain yields increased with increasing N rate and fungicide dose”
Claim · model-written summary
No N x fungicide interaction was revealed in the observed winter wheat grain yields.
- Taxon
- winter wheatTriticum aestivume0
- Outcome
- observed grain yieldse3
- Direction
- did not reveale3
- Qualifier
- N×fungicide interactionse3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The effects of nitrogen (N) rate and timing on need for fungicide application in winter wheat ( Triticum aestivum ) were investigated”
e3“However, the observed grain yields did not reveal any N×fungicide interactions”
Claim · model-written summary
Septoria leaf spot had a considerably higher impact on winter wheat grain yield than powdery mildew.
- Taxon
- winter wheatTriticum aestivume0
- Interactor
- septoria leaf spote4pathogen
- Outcome
- grain yielde4
- Direction
- highere4
- Comparator
- mildewe4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The effects of nitrogen (N) rate and timing on need for fungicide application in winter wheat ( Triticum aestivum ) were investigated”
e4“They demonstrated that septoria leaf spot had a considerably higher impact on grain yield than mildew”
Claim · model-written summary
The optimal fungicide dose increased almost linearly with N rate above a minimum N rate.
- Taxon
- winter wheatTriticum aestivume0
- Treatment
- N ratee5
- Outcome
- optimal fungicide dosee5
- Direction
- increased almost linearlye5
- Qualifier
- above a minimum N ratee5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The effects of nitrogen (N) rate and timing on need for fungicide application in winter wheat ( Triticum aestivum ) were investigated”
e5“The optimal fungicide dose increased almost linearly with N rate above a minimum N rate, but with a large dependency on price relations”
Claim · model-written summary
Early applied nitrogen caused a higher demand for disease control in winter wheat.
- Taxon
- winter wheatTriticum aestivume0
- Treatment
- Early applied Ne6
- Outcome
- demand for disease controle6
- Direction
- highere6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The effects of nitrogen (N) rate and timing on need for fungicide application in winter wheat ( Triticum aestivum ) were investigated”
e6“Early applied N caused a higher demand for disease control”
Claim · model-written summary
The estimated optimal N rate for untreated diseased winter wheat crops was 60 kg N/ha lower than for crops without disease.
- Taxon
- winter wheatTriticum aestivume0
- Treatment
- untreated diseased cropse7
- Outcome
- optimal N fertilizer ratee7
- Direction
- lowere7
- Value
- 60 kg N/hae7
- Comparator
- crops without diseasee7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The effects of nitrogen (N) rate and timing on need for fungicide application in winter wheat ( Triticum aestivum ) were investigated”
e7“The estimated optimal N fertilizer rate for untreated diseased crops was 60 kg N/ha lower than for crops without disease”
Claim · model-written summary
Fungicides with twice the efficacy of the EBI fungicides used would raise the optimal N rate by about 20 kg N/ha.
- Taxon
- winter wheatTriticum aestivume0
- Treatment
- fungicides with an efficacy twice that of the EBI-fungicidese7
- Outcome
- optimal N ratee7
- Direction
- increasee7
- Value
- c . 20 kg N/hae7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The effects of nitrogen (N) rate and timing on need for fungicide application in winter wheat ( Triticum aestivum ) were investigated”
e7“The use of fungicides with an efficacy twice that of the EBI-fungicides used in this experiment would increase the optimal N rate by c . 20 kg N/ha”
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See all 2,061 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.