Abstract
Abstract The nitrogen (N) status of wheat at specific growth stages has potential in predicting yield goals and supplemental N fertilizer requirements but there is a need for a simple and reliable method for field determination of wheat (Triticum aestivum L.) N status under different management schemes. This field study was conducted for two seasons (1989–90 and 1990–91) on a Norfolk sl (fine‐loamy, siliceous thermic Typic Kandiudults) in east‐central Alabama. Treatment variables were tillage, fungicide and N rate. Tillage treatments were disk/harrow or paraplow. Fungicide treatments were no fungicide or propiconazole (Tilt®) applied at Feekes growth stage (GS) 8. Nitrogen rates were a 0‐N control and 45, 90, 134, or 179 kg N/ha applied in a two‐way split with 22.5 kg N/ha applied at planting and the remainder applied in mid‐February. Whole plant samples at GS 3 and 5, and flag leaf samples at GS 10.51 were analyzed for N; a hand‐held meter was used to measure chlorophyll concentrations at these sampling times also. The most consistent yield response was to fungicide, especially at higher N rates, with increases ranging from 15 to 62%. Paraplowing also affected grain yield response to N application. Leaf chlorophyll meter readings were significantly correlated to tissue N concentration and grain yield. The best predictor of grain yield was N uptake at GS 5, however, multiple regression models that included chlorophyll meter readings and dry matter at GS 5 were comparable to N uptake as predictors of yield. Chlorophyll meter readings have potential to be combined with other simple measurements, e.g., dry matter determination and/or soil nitrate tests, to develop quick and reliable methods for predicting N fertilizer requirements for winter wheat.
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Claims 7
Claim · model-written summary
Fungicide raised yield by 15 to 62%, particularly at higher nitrogen rates.
- Taxon
- wheat
Triticum aestivumt0 - Treatment
- fungicidee0
- Outcome
- yielde0
- Direction
- increasese0
- Value
- 15 to 62%e0
- Qualifier
- higher N ratese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The most consistent yield response was to fungicide, especially at higher N rates, with increases ranging from 15 to 62%”
t0“wheat”
Claim · model-written summary
Paraplowing affected the grain yield response to nitrogen.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- Paraplowinge0
- Outcome
- grain yield responsee0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Paraplowing also affected grain yield response to N application”
t0“wheat”
Claim · model-written summary
Chlorophyll meter readings correlated significantly with tissue nitrogen concentration.
- Taxon
- wheatTriticum aestivumt0
- Organ / stage
- Leafe0
- Outcome
- tissue N concentratione0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Leaf chlorophyll meter readings were significantly correlated to tissue N concentration and grain yield”
t0“wheat”
Claim · model-written summary
Chlorophyll meter readings correlated significantly with grain yield.
- Taxon
- wheatTriticum aestivumt0
- Organ / stage
- Leafe0
- Outcome
- grain yielde0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Leaf chlorophyll meter readings were significantly correlated to tissue N concentration and grain yield”
t0“wheat”
Claim · model-written summary
Nitrogen uptake at GS 5 was the best grain yield predictor.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- predictor of grain yielde0
- Comparator
- N uptake at GS 5e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The best predictor of grain yield was N uptake at GS 5”
t0“wheat”
Claim · model-written summary
Models combining chlorophyll readings and dry matter at GS 5 were comparable to nitrogen uptake for yield prediction.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- predictors of yielde0
- Comparator
- N uptakee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“multiple regression models that included chlorophyll meter readings and dry matter at GS 5 were comparable to N uptake as predictors of yield”
t0“wheat”
Claim · model-written summary
The authors proposed combining meter readings with dry matter or soil nitrate tests to predict fertilizer needs.
- Taxon
- winter wheatTriticum aestivume0
- Outcome
- predicting N fertilizer requirementse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Chlorophyll meter readings have potential to be combined with other simple measurements, e.g., dry matter determination and/or soil nitrate tests, to develop quick and reliable methods for predicting N fertilizer requirements for winter wheat”
The same questions in other papers
fungicide · yield · Triticum aestivum (wheat)Positive and negative results
231 papers in the same direction as this paper · 30 in the opposite direction
- negative
- no effect
- no effect
258 papers more in this group
See all 262 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.