Individual and Combined Use of Sawdust and Weed Mat Mulch in a New Planting of Northern Highbush Blueberry. III. Yield, Fruit Quality, and Costs

A 4-year trial was established in Oct. 2016 in western Oregon to evaluate the effects of various in-row mulch treatments on yield, fruit quality, and costs of installation and maintenance during establishment of northern highbush blueberry (Vaccinium corymbosum L. ‘Duke’). The treatments included douglas fir [Pseudotsuga menziesii (Mirb.) Franco] sawdust, black weed mat (woven polypropylene groundcover), green weed mat, and sawdust covered with black or green weed mat. Fruit were harvested during 2018–20 (second through fourth growing seasons). Weed mat color had no effect on yield or fruit quality. In 2018, yield was higher with black weed mat over sawdust mulch than with black weed mat alone, whereas mulch had no effects during 2019 and 2020, or on cumulative yield. Percent total soluble solids in the berries was highest with sawdust and weed mat alone compared with weed mat over sawdust mulches, whereas berry weight, diameter, and firmness were unaffected by mulch. Sawdust was the most expensive mulch over the lifespan of the planting because it required replenishment after 2 years. Black weed mat over sawdust resulted in the highest net profit when fruit sales and cost of materials and labor were considered.

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Effects of Machine-Harvest Interval on Fruit Quality of Fresh Market Northern Highbush Blueberry

Horticulturae ◽

10.3390/horticulturae7080245 ◽

2021 ◽

Vol 7 (8) ◽

pp. 245

Author(s):

Yixin Cai ◽

Fumiomi Takeda ◽

Brian Foote ◽

Lisa Wasko DeVetter

Keyword(s):

Fruit Quality ◽

Titratable Acidity ◽

Vaccinium Corymbosum ◽

Soluble Solids ◽

Highbush Blueberry ◽

Labor Costs ◽

Fresh Market ◽

Harvest Intervals ◽

Northern Highbush Blueberry

Machine harvesting blueberry (Vaccinium sp.) alleviates labor costs and shortages but can reduce fruit quality. Installation of softer catching surfaces inside modified over-the-row harvesters (modified OTR) and adjusting harvest intervals may improve fruit quality and packout. The objective of this study was to determine the effect of harvest interval on fruit quality of fresh market northern highbush blueberry (Vaccinium corymbosum L.) harvested using a modified OTR. ‘Liberty’ blueberry bushes were harvested by hand or using a modified OTR at 3-, 10-, and 14-day intervals in 2019 and at 7-, 11-, and 14-day intervals in 2020. Hand-harvested ‘Liberty’ had greater packout and firmness than machine-harvested fruit. Machine harvesting at the 3-day interval in 2019, and the 14-day interval in 2020 reduced packout from 70–80% to 60% and 54%, respectively. In 2019, machine harvesting at a 3-day interval overall resulted in fruit with greater firmness, higher titratable acidity (TA), and lower total soluble solids (TSS) and SS/TA, compared to other harvest intervals. In 2020, the 7-day machine-harvest interval had a greater TA and lower TSS/TA, compared to the 11- and 14-day intervals. Overall, modified OTR machine-harvest intervals can be extended to 10–11 days for fresh market northern highbush cultivars such as ‘Liberty’ grown in northwest Washington.

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Potential of Deficit Irrigation, Irrigation Cutoffs, and Crop Thinning to Maintain Yield and Fruit Quality with Less Water in Northern Highbush Blueberry

HortScience ◽

10.21273/hortsci11533-16 ◽

2017 ◽

Vol 52 (4) ◽

pp. 625-633 ◽

Cited By ~ 3

Author(s):

Khalid F. Almutairi ◽

David R. Bryla ◽

Bernadine C. Strik

Keyword(s):

Water Use ◽

Fruit Quality ◽

Deficit Irrigation ◽

Vaccinium Corymbosum ◽

Soluble Solids ◽

Highbush Blueberry ◽

Stem Water Potential ◽

Full Irrigation ◽

Northern Highbush Blueberry ◽

Stem Water

Drought and mandatory water restrictions are limiting the availability of irrigation water in many important blueberry growing regions, such as Oregon, Washington, and California. New strategies are needed to maintain yield and fruit quality with less water. To address the issue, three potential options for reducing water use, including deficit irrigation, irrigation cutoffs, and crop thinning, were evaluated for 2 years in a mature planting of northern highbush blueberry (Vaccinium corymbosum L. ‘Elliott’). Treatments consisted of no thinning and 50% crop removal in combination with either full irrigation at 100% of estimated crop evapotranspiration (ETc), deficit irrigation at 50% ETc (applied for the entire growing season), or full irrigation with irrigation cutoff for 4–6 weeks during early (early- to late-green fruit) or late (fruit coloring to harvest) stages of fruit development. Stem water potential was similar with full and deficit irrigation but, regardless of crop thinning, declined by 0.5–0.6 MPa when irrigation was cutoff early and by >2.0 MPa when irrigation was cutoff late. In one or both years, the fruiting season was advanced with either deficit irrigation or late cutoff, whereas cutting off irrigation early delayed the season. Yield was unaffected by deficit irrigation in plants with a full crop load but was reduced by an average of 35% when irrigation was cutoff late each year. Cutting off irrigation early likewise reduced yield, but only in the 2nd year when the plants were not thinned; however, early cutoff also reduced fruit soluble solids and berry weight by 7% to 24% compared with full irrigation. Cutting off irrigation late produced the smallest and firmest fruit with the highest soluble solids and total acidity among the treatments, as well as the slowest rate of fruit loss in cold storage. Deficit irrigation had the least effect on fruit quality and, based on these results, appears to be the most viable option for maintaining yield with less water in northern highbush blueberry. Relative to full irrigation, the practice reduced water use by 2.5 ML·ha−1 per season.

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New Foliar-applied Biofilm Had No Impact on Splitting or Fruit Quality in ‘Elliott’ and ‘Legacy’ Blueberry in Oregon

HortTechnology ◽

10.21273/horttech04196-18 ◽

2018 ◽

Vol 28 (6) ◽

pp. 836-842

Author(s):

Amanda J. Vance ◽

Bernadine C. Strik

Keyword(s):

Fruit Quality ◽

Color Change ◽

Vaccinium Corymbosum ◽

Sprinkler System ◽

Soluble Solids ◽

Highbush Blueberry ◽

Fresh Market ◽

Visual Rating ◽

Berry Size ◽

Current Product

Fresh market blueberry (Vaccinium sp.) sales require high-quality, firm fruit with no significant defects. A new phospholipid biofilm product was developed to reduce splitting and increase firmness when applied directly to blueberry fruit. Two trials were undertaken to test the effects of the biofilm using various application timings and methods. In highbush blueberry cultivar Elliott (Vaccinium corymbosum), four treatments included: 1) rate and timing on the current product label (5- to 10-mm berry size, 10% to 20% color change, and between the first and second harvests), 2) addition of a preharvest timing (5- to 10-mm berry size, 10% to 20% color change, and 7 to 10 days preharvest); 3) starting applications later (10% to 20% color change, 7 to 10 days preharvest, and between the first and second harvests), and 4) a water-sprayed control. Biofilm was applied at a rate of 2 qt/acre for all applications. In highbush blueberry cultivar Legacy (Vaccinium corymbosum × Vaccinium sp.), the same volume of biofilm was applied via an airblast sprayer or through an overhead sprinkler system typically used for chemigation and compared with a water-sprayed control. Data collected included yield (in ‘Elliott’), berry weight, firmness, skin toughness, total soluble solids (TSS), weight loss during storage, percent splitting (in ‘Legacy’), and a visual rating, evaluated on the day of harvest and about 14 and 28 days postharvest. There were no visual defects caused by application of biofilm. Compared with the controls in either study, biofilm had no consistent impact on fruit quality, firmness, shelf life, yield in ‘Elliott’, or splitting in ‘Legacy’.

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Individual and Combined Use of Sawdust and Weed Mat Mulch in a New Planting of Northern Highbush Blueberry I. Impacts on Plant Growth and Soil and Canopy Temperature

HortScience ◽

10.21273/hortsci15122-20 ◽

2020 ◽

Vol 55 (8) ◽

pp. 1280-1287

Author(s):

Bernadine C. Strik ◽

Amanda J. Davis ◽

David R. Bryla ◽

Scott T. Orr

Keyword(s):

Plant Growth ◽

Root System ◽

Canopy Temperature ◽

Canopy Cover ◽

Dry Weight ◽

Vaccinium Corymbosum ◽

Highbush Blueberry ◽

Combined Use ◽

Total Plant ◽

Northern Highbush Blueberry

A 2-year trial was established in Oct. 2016 in western Oregon to evaluate the effects of various in-row mulch treatments on the establishment of northern highbush blueberry (Vaccinium corymbosum L. ‘Duke’). The treatments included douglas fir [Pseudotsuga menziesii (Mirb.) Franco] sawdust, black weed mat (woven polypropylene groundcover), green weed mat, and sawdust covered with black or green weed mat. Soil temperature was unaffected by the color of the weed mat, but it was often higher during the day in beds with weed mat mulch than in those with sawdust alone or sawdust covered with weed mat. Black or green weed mat also resulted in higher canopy temperatures, particularly when sawdust was underneath the weed mat. Plant growth was mainly unaffected by the color of the weed mat, and the maximum depth of the root system was similar among the mulch treatments. However, plants grown with sawdust mulch, with or without weed mat, had a greater canopy width and volume in year 2, a wider root system in both years, and more dry weight (DW) in the crown in year 1 and in the whips in year 2 than those with weed mat alone. Furthermore, plants with weed mat over sawdust were taller in year 1 and had greater canopy cover and more DW in new wood in year 2 than those with sawdust alone, and they had a larger canopy, more root development, and greater DW in the crown, new and old wood, fruit, and pruning wood in one or both years than those with weed mat alone. Over the course of the 2 years of the study, the net gain in total plant DW was lowest when the plants were grown with black weed mat and highest when they were grown with black weed mat over sawdust. Although it was more expensive initially, the use of weed mat over sawdust resulted in more plant growth than weed mat alone due to the insulating properties of the sawdust, and it was more effective for weed control than using sawdust alone.

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Thermal Cooling with Sprinklers or Microsprinklers Reduces Heat Damage and Improves Fruit Quality in Northern Highbush Blueberry

HortScience ◽

10.21273/hortsci15119-20 ◽

2020 ◽

Vol 55 (8) ◽

pp. 1365-1371

Author(s):

Fan-Hsuan Yang ◽

David R. Bryla ◽

Scott T. Orr ◽

Bernadine C. Strik ◽

Yanyun Zhao

Keyword(s):

Air Temperature ◽

Fruit Quality ◽

Ambient Air ◽

Soluble Solids ◽

Highbush Blueberry ◽

Fruit Firmness ◽

Experimental Site ◽

Heat Damage ◽

Berry Weight ◽

Northern Highbush Blueberry

Hot and sunny weather can cause a considerable amount of fruit damage in northern highbush blueberry (Vaccinium corymbosum L.) and result in millions of dollars of crop loss each year. To combat this issue, many growers use over-canopy sprinkler or microsprinkler systems to cool the fruit, but questions remain on the amount of time and frequency these systems should be run and whether they have any effect on fruit quality. Two series of studies were conducted to evaluate the efficacy of using sprinklers or microsprinklers for reducing blueberry fruit temperature and improving fruit quality in western Oregon. With sprinklers, treatments were applied in 2014 and 2015 to ‘Elliott’ blueberry and included irrigation (night) and cooling (day) with sprinklers, sprinkler irrigation (at night only) with no cooling, and drip irrigation with no cooling. The sprinklers were run for cooling for 15 minutes every hour whenever air temperature was ≥32 or 35 °C. Berry temperature declined rapidly within the first 15 minutes of cooling and never exceeded ambient air temperature during the cooling cycles. While the percentage of fruit with heat damage was low even without cooling (<2%), cooling reduced damage to nearly 0% in 1 of 2 years and increased berry weight relative to no cooling in both years when it was run at ≥32 °C. Cooling also reduced the concentration of soluble solids (sugars) in the berries in 2014 but had no effect on yield, fruit firmness, titratable acidity, harvest date, or the total content of phenolics or anthocyanins in the berries in either year. With microsprinklers, cooling was tested at a commercial farm and at an experimental site. At the farm, 1.3-ha blocks of ‘Aurora’ blueberry were irrigated by drip and either had no cooling or were cooled using microsprinklers run continuously or pulsed in 1-hour or 20-minute cycles during three extreme heat events (≥35 °C) in 2015. Continuous cooling was the most effective treatment for reducing berry temperature, but it resulted in wetter conditions, which might impede fruit harvest afterward and increase the presence of slugs, insect pests, and fungal diseases. Pulsed cooling, especially with short cycles, effectively maintained fruit temperatures near that of ambient air and reduced water use by 50%. At the experimental site, cooling with microsprinklers, which in this case were pulsed in 20-min cycles when air temperature was ≥ 32 °C, reduced heat damage in ‘Aurora’ and ‘Elliott’ in 2016. Cooling at this site also increased berry weight by an average of 10% in both cultivars and increased fruit firmness by 32% during the first of three harvests in ‘Aurora’; however, it reduced the concentration of soluble solids in the berries in both cultivars. In general, cooling with microsprinklers used considerably less water than cooling with sprinklers, but it appeared to be equally effective at reducing berry temperature.

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Vegetative and Reproductive Traits of Two Southern Highbush Blueberry Cultivars Grafted onto Vaccinium arboreum Rootstocks

HortScience ◽

10.21273/hortsci.51.7.880 ◽

2016 ◽

Vol 51 (7) ◽

pp. 880-886 ◽

Cited By ~ 3

Author(s):

Bruno Casamali ◽

Rebecca L. Darnell ◽

Alisson P. Kovaleski ◽

James W. Olmstead ◽

Jeffrey G. Williamson

Keyword(s):

Fruit Quality ◽

Reproductive Traits ◽

Vaccinium Corymbosum ◽

Soluble Solids ◽

Soil Conditions ◽

Highbush Blueberry ◽

Canopy Volume ◽

Southern Highbush ◽

Vaccinium Arboreum ◽

Amended Soil

Vaccinium arboreum Marsh is a wild species adapted to high pH (above 6.0) and low organic matter soils (below 2.0%). The use of V. arboreum rootstocks may be a viable option to increase soil adaptation of southern highbush blueberry (SHB) (Vaccinium corymbosum interspecific hybrid) under marginal soil conditions. The objective of this research was to evaluate the vegetative and reproductive traits of ‘Farthing’ and ‘Meadowlark’ SHB own-rooted or grafted onto V. arboreum and grown in pine bark–amended or nonamended soil. The study was conducted from 2012 through 2014 at a research center in Citra, FL, and a grower’s farm in Archer, FL. Vaccinium arboreum rootstock generally induced the same effects in both cultivars. Grafted plants in both soil treatments had reduced canopy growth in the first year after field planting compared with own-rooted plants in amended soil. However, canopy volume of grafted plants was greater than own-rooted plants in nonamended soil and similar to own-rooted plants in amended soil 2 years after field planting for ‘Meadowlark’ and 3 years after planting for ‘Farthing’. Fruit yield was lower in grafted plants compared with own-rooted plants in the first fruiting year (2 years after field planting). By the second fruiting year, yields of grafted plants were similar to or greater than yields of own-rooted plants when grown in nonamended soil, whereas in amended soil, yields of grafted plants were similar to yields of own-rooted plants. Grafted plants had greater mean berry weight, but lower berry firmness; however, the firmness values were still considered acceptable (greater than 160 g⋅mm−1). Internal fruit quality [total soluble solids (TSS) and total titratable acidity (TTA)] was not consistently affected by the rootstock or soil treatments. These results suggest that grafting SHB onto V. arboreum does not increase yield in the establishment years compared with own-rooted SHB when grown in amended soils, but may have the ability to increase yield with no negative effects on fruit quality when grown in nonamended soils.

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Sensitivity of Northern Highbush Blueberry Cultivars to Soil Water Deficits during Various Stages of Fruit Development

HortScience ◽

10.21273/hortsci15493-20 ◽

2020 ◽

pp. 1-9

Author(s):

Khalid F. Almutairi ◽

David R. Bryla ◽

Bernadine C. Strik

Keyword(s):

Soil Water ◽

Fruit Development ◽

Vaccinium Corymbosum ◽

Soluble Solids ◽

Highbush Blueberry ◽

Critical Periods ◽

Volumetric Soil Water Content ◽

Water Deficits ◽

Late Season ◽

Northern Highbush Blueberry

In many regions, water limitations are increasing because of frequent and persistent droughts and competition for water resources. As a result, growers in these regions, including those producing blueberries, must limit irrigation during drier years. To identify the most critical periods for irrigation, we evaluated the effects of soil water deficits during various stages of fruit development on different cultivars of northern highbush blueberry (Vaccinium corymbosum L.). The study was conducted for 2 years in western Oregon and included two early season cultivars, ‘Earliblue’ and ‘Duke’, a midseason cultivar, ‘Bluecrop’, and two late-season cultivars, ‘Elliott’ and ‘Aurora’. Volumetric soil water content and stem water potentials declined within 1 to 2 weeks with no rain or irrigation in each cultivar and were lowest during the later stages of fruit development. Water deficits reduced berry weight by 10% to 15% in ‘Earliblue’ and ‘Elliott’ when irrigation was withheld in the second year during early or late stages of fruit development and by 6% to 9% in ‘Aurora’ when irrigation was withheld in either year during the final stages of fruit development. However, water deficits only reduced yield significantly in ‘Aurora’, which produced 0.8 to 0.9 kg/plant fewer fruit per year when irrigation was withheld during fruit coloring. In many cases, water deficits also reduced fruit firmness and increased the concentration of soluble solids in the berries, but they had inconsistent effects on titratable acidity and sugar-to-acid ratios. As a rule, water deficits were most detrimental during later stages of fruit development, particularly in midseason and late-season cultivars, which ripened in July and August during the warmest and driest months of the year.

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Foliar Applications of Calcium and Boron Do Not Increase Fruit Set or Yield in Northern Highbush Blueberry (Vaccinium corymbosum)

HortScience ◽

10.21273/hortsci12207-17 ◽

2017 ◽

Vol 52 (9) ◽

pp. 1259-1264 ◽

Cited By ~ 4

Author(s):

Matthew Arrington ◽

Lisa Wasko DeVetter

Keyword(s):

Pacific Northwest ◽

Fruit Set ◽

Vaccinium Corymbosum ◽

Climatic Conditions ◽

Tissue Type ◽

Highbush Blueberry ◽

Foliar Sprays ◽

Growing Seasons ◽

The Pacific ◽

Northern Highbush Blueberry

Fruit set in northern highbush blueberry (Vaccinium corymbosum L.) can be low under certain climatic conditions, contributing to reduced yields in northwestern Washington. The mechanisms influencing fruit set are complex, but reduced fruit set may be associated with inadequate nutrient availability during critical stages of flowering, ovule fertilization, and initial fruit development. Calcium (Ca) and boron (B) are of particular interest for reproductive developmental processes and are frequently applied annually by growers in the Pacific Northwest region because of the perception that these nutrients enhance fruit set and corresponding yields. Evaluation of commonly applied products containing these nutrients and their effects on fruit set and yield are of specific importance to justify the application of these nutrients. To address this, commercially available fertilizers containing Ca and B were applied to ‘Draper’ and ‘Bluecrop’ blueberry as foliar sprays, either alone or in combination, during the 2015 and 2016 growing seasons in northwestern Washington. Treatments included calcium chloride (750 and 1500 ppm Ca), calcium sulfate (150 ppm Ca), and tetra borate (125 and 250 ppm B) foliar sprays, repeated six times per season every 7–10 days from early pink bud through petal fall. No significant increases were observed for fruit set, estimated yield, and fruit quality (firmness and berry weight) across the treatments. Increased concentrations of B were observed in leaf tissues in 2015 and 2016, and to a lesser extent fruit tissues. Calcium remained unchanged regardless of treatment and tissue type. Under the conditions of this study, foliar applications of Ca and B did not lead to increased fruit set or yield. This research suggests that other approaches should be explored to increase fruit set and corresponding yields of highbush blueberry grown in northwest Washington.

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Individual and Combined Use of Sawdust and Weed Mat Mulch in a New Planting of Northern Highbush Blueberry. II. Nutrient Uptake and Allocation

HortScience ◽

10.21273/hortsci15271-20 ◽

2020 ◽

Vol 55 (10) ◽

pp. 1614-1621

Author(s):

Bernadine C. Strik ◽

Amanda J. Davis ◽

David R. Bryla

Keyword(s):

Nutrient Concentration ◽

Soil Nutrient ◽

Vaccinium Corymbosum ◽

Nutrient Concentrations ◽

Highbush Blueberry ◽

Plant Parts ◽

Combined Use ◽

Leaf N Concentration ◽

Use Efficiency ◽

Northern Highbush Blueberry

A 2-year trial was established in Oct. 2016 in western Oregon to evaluate the effects of various in-row mulch treatments on establishment of northern highbush blueberry (Vaccinium corymbosum L. ‘Duke’). The treatments included douglas fir [Pseudotsuga menziesii (Mirb.) Franco] sawdust, black weed mat (woven polypropylene groundcover), green weed mat, and sawdust covered with black or green weed mat. For the most part, plant nutrient concentration and content were unaffected by the color of the weed mat. In both years, mulching with weed mat over sawdust reduced soil NO3-N compared with weed mat alone. The only other soil nutrient affected by mulch was K, which was highest with sawdust mulch and intermediate with black weed mat alone in year 2. There were inconsistent effects of mulch on leaf nutrient concentration during the study. In 2018, leaf N concentration was lowest with black weed mat over sawdust. There were few mulch effects on nutrient concentrations in senescent leaves in both years and in harvested fruit in year 2. Mulch had greater effect on nutrient concentration in dormant plant parts after the second growing season than after the first, with the addition of sawdust under weed mat leading to significant differences for many nutrients in various plant parts compared with weed mat alone. Total uptake of N ranged from 12 kg·ha−1 (black weed mat) to 17 kg·ha−1 (black weed mat over sawdust) in year 1 and averaged 33 kg·ha−1 in year 2, with no effect of mulch. Fertilizer use efficiency for N was 8% to 12% in year 1 and 42% in year 2. Uptake of other nutrients was unaffected by mulch and, depending on the year, ranged from 1.3 to 4.3 kg·ha−1 P, 4.0 to 8.0 kg·ha−1 K, 2.1 to 4.9 kg·ha−1 Ca, and 1.0 to 1.5 kg·ha−1 Mg. Each of these other nutrients was derived from the soil or decomposing roots.

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