Abstract
The objective of this study was to test whether a single winter prebloom foliar application of low-biuret urea would increase the yield of 30-year-old `Washington' navel orange trees [ Citrus sinensis (L.) Osbeck] on Troyer citrange rootstock [ C. sinensis `Washington' × Poncirus trifoliata (L.) Raf.]. All trees received a winter (November to January) soil application of urea (0.5 kg N/tree). Trees were maintained under irrigation or irrigation was withheld from 1 Oct. to 1 Mar. To determine the optimal time for foliar urea application, trees in both irrigation main plots received one application of low-biuret urea in mid-November, mid-December, mid-January, or mid-February applied at a rate of 0.16 kg N/tree. There was a set of control trees that only received the soil application of urea. Trees receiving foliar-applied urea in mid-January or mid-February, independent of irrigation treatment, had significantly greater yield and fruit number per tree each year than the control trees for 3 consecutive years. The number of fruit with diameters of 6.1 to 8.0 cm increased significantly as yield increased ( r 2 = 0.88). Withholding irrigation from 1 Oct. to 1 Mar. had a negative impact on yield. Annual winter application of low-biuret urea to the foliage did not significantly increase leaf total N at the end of 3 years.
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Claims 7
Claim · model-written summary
Mid-January foliar urea increased orange yield relative to soil-only controls in each of three years, regardless of irrigation treatment.
Verbatim
e0“Trees receiving foliar-applied urea in mid-January or mid-February, independent of irrigation treatment, had significantly greater yield and fruit number per tree each year than the control trees for 3 consecutive years”
t0“`Washington' Navel Orange”
Claim · model-written summary
Mid-January foliar urea increased orange fruit number per tree relative to soil-only controls in each of three years, regardless of irrigation treatment.
Verbatim
e0“Trees receiving foliar-applied urea in mid-January or mid-February, independent of irrigation treatment, had significantly greater yield and fruit number per tree each year than the control trees for 3 consecutive years”
t0“`Washington' Navel Orange”
Claim · model-written summary
Mid-February foliar urea increased orange yield relative to soil-only controls in each of three years, regardless of irrigation treatment.
Verbatim
e0“Trees receiving foliar-applied urea in mid-January or mid-February, independent of irrigation treatment, had significantly greater yield and fruit number per tree each year than the control trees for 3 consecutive years”
t0“`Washington' Navel Orange”
Claim · model-written summary
Mid-February foliar urea increased orange fruit number per tree relative to soil-only controls in each of three years, regardless of irrigation treatment.
Verbatim
e0“Trees receiving foliar-applied urea in mid-January or mid-February, independent of irrigation treatment, had significantly greater yield and fruit number per tree each year than the control trees for 3 consecutive years”
t0“`Washington' Navel Orange”
Claim · model-written summary
The number of orange fruit 6.1 to 8.0 cm in diameter rose with yield.
Verbatim
e0“The number of fruit with diameters of 6.1 to 8.0 cm increased significantly as yield increased ( r 2 = 0.88)”
t0“`Washington' Navel Orange”
Claim · model-written summary
Withholding irrigation from October through March reduced orange yield.
- Taxon
- `Washington' Navel Oranget0
- Treatment
- Withholding irrigation from 1 Oct. to 1 Mar.e0
- Outcome
- yielde0
- Direction
- negative impacte0
Not reportedComparator
Verbatim
e0“Withholding irrigation from 1 Oct. to 1 Mar. had a negative impact on yield”
t0“`Washington' Navel Orange”
Claim · model-written summary
Annual winter foliar urea did not significantly increase leaf total nitrogen after three years.
- Taxon
- `Washington' Navel Oranget0
- Treatment
- Annual winter application of low-biuret urea to the foliagee0
- Outcome
- leaf total Ne0
- Direction
- did not significantly increasee0
- Qualifier
- at the end of 3 yearse0
Not reportedComparator
Verbatim
e0“Annual winter application of low-biuret urea to the foliage did not significantly increase leaf total N at the end of 3 years”
t0“`Washington' Navel Orange”
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