Abstract
Bloom to fruit maturity is a period of rapid growth and nitrogen (N) uptake in northern highbush blueberry ( Vaccinium corymbosum L.). Sufficient plant-available N is critical during this time, and growers often accomplish this through fertilizer applications from bloom through fruit development. For organic production in northern climates like Washington State, postharvest applications of N fertilizer are not recommended for northern highbush blueberry because they may stimulate excessive vegetative growth, reduce floral bud set, and increase the risk of winter injury through delayed acclimation. However, early fruiting cultivars with the potential for an extended growing season after harvest may benefit from postharvest N applications because the additional N may promote shoot and root growth that could support fruit production in future years while still allowing plants to form floral buds and acclimate to winter temperatures. The objective of this study was to evaluate the potential impacts of postharvest organic N fertilizer applications on ‘Duke’, an early fruiting northern highbush blueberry cultivar. Specific objectives were to determine the effects of postharvest organic N fertilizer application on plant growth, yield, floral bud set, fruit quality, cold hardiness, tissue macronutrient concentrations, and select soil properties. Four treatments varying in the timing of N application were evaluated in a commercial ‘Duke’ field in eastern Washington using a single fertilizer rate of 130 kg⋅ha −1 N from 2018 to 2020. The organic fertilizer N source was a liquid fertilizer derived from digested plant materials. The experimental design was a randomized complete block design with four replications and treatments included the following: control (100% of N applied preharvest); 80/20 (80% preharvest, 20% postharvest); 70/30 (70% preharvest, 30% postharvest); and 60/40 (60% preharvest, 40% postharvest). Although the year influenced measured variables, including yield, floral bud set, fruit quality, tissue nutrients, and soil properties, few treatment effects were observed across the 3-year study. Cold hardiness was only impacted once (8 Feb. 2020), and floral buds were overall hardy to extreme minimum winter temperatures for the region. This project showed that applying postharvest organic N as a liquid fertilizer had no negative consequences on productivity metrics for an early fruiting blueberry cultivar grown in a region with an extended growing season, thus providing growers with more flexibility when timing their fertilizer applications. Results may differ for other fertilizer sources, and further monitoring of soil NO 3 -N accumulation should be conducted to gain a better understanding of its dynamics and the potential for risks.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by-nc-nd. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 6
Claim · model-written summary
Year influenced yield, floral bud set, fruit quality, tissue nutrients, and soil properties.
- Taxon
- Northern Highbush Blueberry
Vaccinium corymbosumt0 - Outcome
- yield, floral bud set, fruit quality, tissue nutrients, and soil propertiese0
- Setting
- commercial ‘Duke’ field in eastern Washingtone1
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the year influenced measured variables, including yield, floral bud set, fruit quality, tissue nutrients, and soil properties”
e1“commercial ‘Duke’ field in eastern Washington”
t0“Northern Highbush Blueberry”
Claim · model-written summary
Few fertilizer-timing treatment effects were observed across the three-year study.
- Taxon
- Northern Highbush BlueberryVaccinium corymbosumt0
- Treatment
- treatmente0
- Outcome
- treatment effectse0
- Direction
- fewe0
- Value
- 3-yeare0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“few treatment effects were observed across the 3-year study.”
t0“Northern Highbush Blueberry”
Claim · model-written summary
Cold hardiness was affected once, on 8 February 2020.
- Taxon
- Northern Highbush BlueberryVaccinium corymbosumt0
- Outcome
- Cold hardinesse0
- Value
- once (8 Feb. 2020)e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Cold hardiness was only impacted once (8 Feb. 2020), and floral buds were overall hardy to extreme minimum winter temperatures for the region.”
t0“Northern Highbush Blueberry”
Claim · model-written summary
Floral buds were generally hardy to regional extreme minimum winter temperatures.
- Taxon
- Northern Highbush BlueberryVaccinium corymbosumt0
- Outcome
- floral buds were overall hardye0
- Qualifier
- extreme minimum winter temperatures for the regione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“floral buds were overall hardy to extreme minimum winter temperatures for the region.”
t0“Northern Highbush Blueberry”
Claim · model-written summary
Postharvest organic liquid nitrogen fertilizer had no negative productivity consequences for the early-fruiting cultivar.
- Taxon
- blueberrye0
- Treatment
- postharvest organic N as a liquid fertilizere0
- Outcome
- productivity metricse0
- Direction
- no negative consequencese0
- Qualifier
- region with an extended growing seasone0
Not reportedComparator
Verbatim
e0“applying postharvest organic N as a liquid fertilizer had no negative consequences on productivity metrics for an early fruiting blueberry cultivar grown in a region with an extended growing season”
Claim · model-written summary
The authors recommend further monitoring of soil NO 3 -N accumulation.
- Taxon
- Northern Highbush BlueberryVaccinium corymbosumt0
- Outcome
- further monitoring of soil NO 3 -N accumulatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“further monitoring of soil NO 3 -N accumulation should be conducted to gain a better understanding of its dynamics and the potential for risks.”
t0“Northern Highbush Blueberry”
The same questions in other papers
fertilization · yield · VacciniumResults differ
12 papers in the same direction as this paper · 12 in the opposite direction
- positive
- positive
- positive
21 papers more in this group
See all 25 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.