Progress 04/01/09 to 03/31/14
Outputs
Target Audience: The target audiences for this project were researchers and Extension professionals working with commercial blueberry production, blueberry growers, industry professionals such as chemical and fertilizer sales personnel and consultants. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? In-service tranings 1. Mechanical Harvest of Blueberries for Fresh Markets at the University of California Kearney Agricultural Research and Education Center, Parlier, CA, May 21, 2013.Audience was farm advisors, county agents, and Extension specialists. 2. Extension and research programing for commercial blueberry production in Florida, March 27, 2014. Citra, FL. Target audience was UF state and county faculty with responsibilities in commercial blueberry production. How have the results been disseminated to communities of interest? Presentations have been made at the following meetings - 1. 2010 - American Society for Horticultural Science national annual meeting, Palm Desert, CA 2. 2011 - American Society for Horticultural Science national annual meeting, Hawaii. 3. 2012 - American Society for Horticultural Science national annual meeting.Miami, FL 4. Blueberry/blackberry field day and tasting, University of California Kearney Agricultural Research and Education Center, Parlier, CA 5. 2013 - American Society for Horticultural Science national annual meeting. Palm Desert, CA 6. 2013 Florida Blueberry Growers' Association Fall Short Course, Plant City, FL 7. 2014 SE RegionalFruit and Vegetable Conference, Savannah, GA 8. Florida Blueberry Growers' Association Spring Meeting, Plant City, FL. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Objective1. Experiment 1. Reduce pine bark, water, and fertilizer inputs. Canopy volume, berry yield per bush and mean berry size (fresh weight) were greater for plants grown in pine bark amended soils than for plants grown in non-amended soils. There were no differences in canopy volume, yield per bush , or berry size among the treatments where pine bark was used (pine bark bed, incorporated pine bark or incorporated pine bark plus pine bark mulch). The incorporated pine bark system used half as much pine bark as the pine bark bed system or the incorporated pine bark plus pine bark mulch system with no reduction in plant canopy growth or berry yield. Experiment 2. Preliminary results suggest that southern hgihbush blueberry grafted on V. arboreum are more vigorous and productive on low organic matter soils without pine bark amendments than own-rooted southern highbush blueberry. Experiment 3. Lysimeter studies determined seasonal monthly water use of Emerald southern highbush blueberry plants in Florida on pine bark amended soils. Peak periods of water use were April and May during fruit ripening and August and Septemberas plants reach maximum canopy size following summer pruning. Objective 2. Concentrate Florida's blueberry harvest earlier in the lucrative market window of April 1 through May 20. Summer pruning experiments showed that moderate pruning (30% canopy removal) done in June produced higher yields and earlier fruit ripening the following year than 60% canopy removal for Jewel southern highbush blueberry. Emerald yield or harvest date were not affected by pruning severity or timing. Post pruning tipping in July did not increase berry yield in either cultivar. Objective 3) Breeding and selecting for firm-fruited blueberries suitable for mechanical harvest - During the fruiting season of 2013, 200 seedlings were selected from crisp x crisp crosses made the previous year. Plants with high yield, high vigor, and distinct fruit crispness were chosen. 200 cuttings from each plant were made and grow-out in a field nursery nursery in September, and planted in a commercial test plot at Straughn Farms in Windsor, Florida and also in Homerville Georgia. The plants are now growing and the clones will be evaluated during the next several years for adaptation to mechanicla harvesting for fresh markets.
Publications
- Type:
Other
Status:
Published
Year Published:
2009
Citation:
Mejia, L.E., P. Miller and J.G. Williamson. 2009. Use of pine bark in soil management of southern highbush blueberries
(Vaccinium corymbosum L.) HortScience 44: 1001. (abstract).
- Type:
Other
Status:
Published
Year Published:
2010
Citation:
Ferguson, B. Y. and J.G. Williamson. 2010. Nitrogen rate and form affects growth and yield of southern highbush blueberry in pine bark beds. HortScience 45 (8) Supplement S 315.(abstract).
- Type:
Other
Status:
Published
Year Published:
2012
Citation:
Kovaleski, A.P., J.G. Williamson and R.L. Darnell. 2012. Vegetative and reproductive traits of southern highbush blueberry under different summer pruning systems. HortScience. 47:S327. (abstract, poster).
- Type:
Other
Status:
Published
Year Published:
2013
Citation:
Kovaleski, A.P., J.G. Williamson and R.L. Darnell. 2013. Effect of timing and intensity on vegetative and reproductive traits
of southern highbush blueberry. HortScience: 48: S197. (abstract, presentation).
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Williamson, J.G. and W.O. Cline. 2013. Mechanized harvest of southern highbush blueberries for the fresh market: An introduction and overview of the workshop proceedings. HortTechnology 23: 416-419.
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Sargent , S.A., A. D. Berry, J. G. Williamson and J. W. Olmstead. 2013. Postharvest quality of mechanically and hand harvested southern highbush blueberry fruit for fresh market. HortTechnology 23: 437-441.
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Progress 10/01/13 to 03/31/14
Outputs
Target Audience: In-service training 1. Extension and research programing for commercial blueberry production in Florida, March 27, 2014. Citra, FL. Target audience was UF state and county faculty with responsibilities in commercial blueberry production. Industry Presentations 1. Sparkleberry: a potential rootstock for southern highbush, Southeast Fruit and Vegetable Conference, Jan. 9, 2014, Savannah, Ga. Target audience was blueberry growers and researchers from the southeastern U.S. 2. Summer pruning southern highbush blueberries in Florida, Florida Blueberry Growers’ Association Spring Meeting, Feb. 20, 2014, Plant City, FL. Target audience was commercial blueberry growers and other industry professionals, primarily from Florida. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? A research and Extension planning meeting was held March 27 in Citra Florida at the University of Florida Plant Science Research and Education Center. The training was attended by county and state faculty that have responsibility for commercial blueberry production in Florida. The purpose of the meeting was to identify priority research and Extension needs. How have the results been disseminated to communities of interest? Summer pruning southern highbush blueberries in Florida, Florida Blueberry Growers’ Association Spring Meeting, Feb. 20, 2014, Plant City, FL. Sparkleberry: a potential rootstock for southern highbush, Southeast Fruit and Vegetable Conference, Jan. 9, 2014, Savannah, Ga. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Objective 2) Summer pruning timing and intensity - Plant canopy size, fruit yield and mean berry weight, and time of flower bud differentiation were determined for Jewel and Emerald southern highbush blueberry in Citra, Florida. In general for Jewel, 30 percent canopy removal provided greater yield and earlier harvest date than 60 percent canopy removal. There were no differences in yield for berry size among pruning treatments for Emerald. There was no apparent advantage to post-pruning shoot tipping with respect to yield or fruit size for either cultivar. Flower bud development occurred earlier in Emerald, late summer, than in Jewel, mid-fall. Objective 3) Breeding and selecting for firm-fruited blueberries suitable for mechanical harvest- During the fruiting season of 2013 we selected 200 seedlings froma crisp x crisp crosses made the previous year. Plants with high yield, high vigor, and distinct fruit crispness were chosen. 200 cuttings from each plant were made and grow-out in a field nursery nursery in September, and planted in a commercial test plotatStraughn Farmsin Windsor, Florida and also in Homerville Georgia. The plants are now growing and the clones will be evaluated during the next several years.
Publications
- Type:
Journal Articles
Status:
Accepted
Year Published:
2013
Citation:
Williamson, J.G. and W.O. Cline. 2013. Mechanized harvest of southern highbush blueberries for the fresh market: An introduction and overview of the workshop proceedings. HortTechnology 23: 416-419.
Sargent , S.A., A. D. Berry, J. G. Williamson and J. W. Olmstead. 2013. Postharvest quality of mechanically and hand-harvested southern highbush blueberry fruit for fresh market. HortTechnology 23: 437-441.
Casamali, B., R.L. Darnell and J.G. Williamson. 2013. Vaccinium arboretum: A rootstock for southern highbush blueberry? HortScience. 48: S279 (abstract).
Kovaleski, A.P., J.G. Williamson and R.L. Darnell. 2013. Effect of timing and intensity on vegetative and reproductive traits of southern highbush blueberry. HortScience: 48: S197 (abstract).
Williamson, J.G., L.E. Mejia, B. Ferguson. 2013. Seasonal water use of southern highbush blueberry in Florida. HortScience. 48: S426. (abstract).
Sargent, S.A., J.G. Williamson, A.D. Berry and J.W. Olmstead. 2013. Effect of harvest delay of southern highbush blueberry on resistance to impact and storage. HortScience: 48: S400. (abstract).
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Progress 10/01/12 to 09/30/13
Outputs
Target Audience: An oral presentation “Effect of timing and intensity of summer pruning on vegetative and reproductive traits of southern highbush blueberry” was presented at the annual conference of the American Society for Horticultural Science, July 25, 2013. Palm Desert, CA. A presentation entitled “Effect of pruning time and intensity on vegetative and reproductive growth of southern highbush blueberry in Florida” was presented at the Fall Blueberry Short Course in Plant City, FL on September 19, 2013. More than 300 people attended this meeting. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest? Effect of timing and intensity on vegetative and reproductive traits of southern highbush blueberry- oral presentation at the Annual American Society for Horticultural Sciences, July 25, 2013. Palm Desert, CA. Effect of pruning time and intensity on vegetative and reproductive growth of southern highbush blueberry in Florida -oral presentation at the 2013 Fall Blueberry Short Course, Septemeber 19, 2013. Plant City, FL. What do you plan to do during the next reporting period to accomplish the goals? Evaluate the effects of summer pruning treatments on flower bud initiation, canopy volume, and bloom progression of 'Emerald' and 'Jewel'southern highbush blueberry.
Impacts
What was accomplished under these goals?
Impact. Our work demonstrated that blueberry plants are shallow-rooted when grown under current management systems with about 80% of the absorbing roots in the top 8 to 10 inches of soil profile. Thus, blueberries are very drought susceptible under current management systems. Ourstudies also demonstrated that pine bark, either incorporated or applied as a bed on topof the soil, reduced drought stress of blueberry and increased vegetative and reproductive growth compared to no pine bark amendment.Further, our studies showed that growth and yield was as good forpine bark incorporated into soilas it was for pine bark beds (the industry standard) which typically usesat least twice as much bark as the incorporation method. Therefore growers can reduce pine bark inputs by approximately 50% by using the incorporation method vs. thepine bark bed method. This could result in a $2000 to $3000per acre savings during planting establishment. This information has been presented at numerous grower meetings and field days andmany new plantings are being established using bark incorporation instead of pine bark beds. Summer pruning experiments show that response to the timing and intensity of summer pruning is cultivar specific. However, generally it appeared that plantyield the season followingpruning was greaterfor moderate pruning (30% canopy removal) than for heavy pruning (60% canopy removal).Also the heavy pruning treatment resulted in delayed fruit ripening compared to moderate pruning treatments for 'Jewel'. These findings areimportant since many growers prune heavily (50%+ canopy removal) which probably delays berry ripening and reduces yield the followingseason for many cultivars. This workhas been reported at grower meetings, field days and scientific meetings. The results are too recent to document changes in grower practices at this time. Harvest labor is a primary concern for blueberry growers. Early-season, fresh market berries are typically harvested by hand. While breeding and selecting new blueberry cultivars is a long-term endeavor, progress has been made toward the development of firm-fruited cultivars which should perform better than existing cultivars during machine harvesting.Although the genetics ofberry firmness are not fully understood, someof the advanced selectionshave firmer flesh than the major cultivars currently grown for the early-season fresh market. These firm-fruited selections will be useful in developing cultivars better suited for machine harvest than cultivars currently grown for fresh markets. Objective 1. reduce pine bark, fertilizer and water inputs by increasing their use efficiencies. No new activity to report during this period. Objective 2. Summer pruning experiments were conducted to address objective: 2) concentrate Florida's berry harvest earlier in the lucrative market window between April and May , and to increase yield. The plant material used for this study consists of ‘Emerald’ and ‘Jewel’ southern highbush blueberries planted in 2006 and located at UF-IFAS Plant Science Research and Education Unit in Citra, FL. After fruit harvest in spring 2013, 6 pruning treatments were imposed: No summer pruning control; Detailed hand pruning control; Prune 30% of existing foliage in early June; Prune 30% of existing foliage in mid-July; Prune 30% of existing foliage in early June followed by shoot tipping in mid-July; Prune 60% of existing foliage in early June, followed by shoot tipping in mid-July. Except for the control treatments, all pruning treatments were done mechanically, pruning the plants’ top and sides using a hand-held hedge trimmer. A randomized complete block design was used, with 4-plant plots (1 guard plant in each side and 2 central data plants) and 6 replications. Flower bud initiation. Beginning in August, shoot tips from ‘Emerald’ were sampled from all pruning treatments and evaluated for flower bud initiation and development under a dissecting scope in the lab. Sampling of ‘Jewel’ shoots began in October. Microscopic evaluation of developing buds indicated that the conversion of vegetative to flower buds began in August in ‘Emerald’ but not until October in ‘Jewel’. Canopy volume. For ‘Jewel’, canopy volume at the end of the growing season was greatest for the non-pruned controls, followed by the hand pruned treatment. The most severe pruning treatment, 60% June + tipping, produced the smallest canopy volume. For ‘Emerald’, the non-pruned control had greater conopy volume than any of the other treatments and the hand pruned treatment had greater canopy volume than either of the treatments with tipping and the late (July) pruning treatment. In 2013, canopy regrowth for ‘Jewel’ was not affected by pruning treatment, but for ‘Emerald’ canopy regrowth was greatest for the 30% June treatment. The 30% June + tipping and 30% July treatments had the least regrowth. Regrowth of individual shoots of ‘Jewel’ and ‘Emerald’ were greatest for the non-pruned control and the 60% June + tipping treatments and least for the 30% July treatment. Bloom progression. The hand pruned treatment generally had advanced bloom compared to the other treatments while the 30% June + tipping and the 30% July treatments tended to have delayed bloom development. Bloom was most advanced for the non-pruned and 30% July treatments and least advanced for the 60% June + tipping treatment. Berry yield. Plants were harvested beginning in 1 April through 3 June and the yields were recorded for each plant. The highest yielding plants for ‘Jewel’ were those from the 30% June pruning treatment followed by tipping. That treatment had an average of approximately 13 pounds/plant for the last two seasons. For seasonal distribution of yield, the only treatment that differed was the 60% pruning in June followed by tipping, which had most of its yield concentrated at the end of the season. Total yield of‘Emerald’ was not affected by pruning treatments. Berry size (weight). There were no differences among treatments for mean weight for ‘Emerald’ in 2013. For ‘Jewel’, mean berry weight was greatest for the non-pruned control (1.71 g/berry) and the 30% July treatment (1.75 g/berry) and least for the 60% June + tipping treatment (1.41 g/berry). Objective 3. Germplasm was evaluated from crosses to address objective: 3) develop firm-fleshed blueberry cultivars suitable for mechanical harvest. From examination of approximately 8,000 fruiting seedlings grown from 4 different crosses in which both parents had “crisp” texture, it was concluded that crisp texture is highly heritable, but the exact genetics is not fully understood. Some of the crosses produced 20 to 50% seedlings that were rated as “crisp”, but the degree of crispness varied both within and outside the group considered to be fully crisp. It seems likely that clonally-propagated hybrid rootstocks could be developed from advanced-generation selections from highbush x V. arboreum crosses that would be easy to propagate from cuttings, would sprout sparingly or not at all from the root, would be highly vigorous, and would be more resistant to root diseases than either parent. Vigor, fruitfulness, and berry quality varied tremendously among 2,000 backcross -1 seedlings -- (highbush cultivar x V. arboreum) x highbush cultivar – crosses when 5-year old seedlings from 20 crosses were evaluated in the field. The most vigorous seedlings exceed in vigor any of the 2,000 highbush seedlings planted in the same field for comparison.
Publications
- Type:
Other
Status:
Accepted
Year Published:
2013
Citation:
Kovaleski, A.P., J.G. Williamson and R.L. Darnell. 2013. Effect of timing and intensity on vegetative and reproductive traits of southern highbush blueberry. HortScience: 48: S197. (abstract).
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Progress 10/01/11 to 09/30/12
Outputs
OUTPUTS: The plant material used for this study consists of Emerald and Jewel southern highbush blueberries planted in 2006 and located at UF-IFAS Plant Science Research and Education Unit in Citra, FL. The field is on pine bark raised beds, and the plants are spaced at 0.9 m in rows with 2.7 m between rows. The plants are irrigated with microsprinklers, and have overhead irrigation for frost protection and are grown using standard practices with regards to irrigation, fertilization, and pest and disease management. After fruit harvest, 6 summer pruning treatments were imposed: 1)no summer pruning control; 2)detailed hand pruning control; 3)prune 30 percent of existing foliage in early June; 4)prune 30 percent of existing foliage in mid-July; 5)prune 30 percent of existing foliage in early June followed by shoot tipping in mid-July; and 6)prune 60 percent of existing foliage in early June, followed by shoot tipping in mid-July. Except for the control treatments, all pruning treatments were done mechanically, pruning the plants' top and sides using a hand-held hedge trimmer. A randomized complete block design was used, with 4-plant plots (1 guard plant in each side and 2 central data plants) and 6 replications. In late December, 2011, hydrogen cyanamide(used to enhance winter chilling) was applied and caused the remaining leaves to abcise. Canopy volume, berry yield and mean berry size, and incidence of stem blight were evaluated in 2012. PARTICIPANTS: Jeffrey Williamson, primary investigator, is responsible for overseeing the field project and advising the graduate assistant. Rebecca Darnell, co-primary investigator, is responsible for overseeing laboratory work and advising the graduate assistant. Al Kovalesky, graduate assistant, is responsible for data collection and analysis. Eric Ostmark, field biologist, is responsible for maintaining the experimental plots. TARGET AUDIENCES: The research site in Citra FL was highlighted at a blueberry grower field day on March 6, 2012. The research objectives were presented to the growers and the importance of the project was described. Preliminary results of the project were reported at a blueberry grower meeting on October 30, 2012 in Plant City, FL. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Non-pruned and hand pruned plants had the largest plant canopy volumes for both cultivars following the 2011 growing season, while 60 percent June+tip had the smallest. Regrowth was greater for the non-pruned control than for any other treatment except 30 percent June. Regrowth was lowest in the 30 percent July pruning treatment for both cultivars, probably because of limited time for regrowth to occur for that treatment compared to the earlier pruning treatments. Berry size of Jewel was larger for the 60 percent June+tip, 30 percent July, and hand pruned treatments compared with the non-pruned control. However, berry size was not affected by pruning treatments for Emerald. Early-season berry yield (March 29 - April 5) of Jewel was greatest for the July pruning treatment. There was a trend (p less than 0.10) for greater berry harvest for the 30 percent June + tip treatment than for most of the other pruning treatments between April 9 and April 16. There was no effect of pruning treatment on time of berry harvest for Emerald. There was no effect of pruning treatment on cumulative berry yield for either cultivar during the 2012 season. Incidence of stem blight was low throughout the plots in 2012 and not affected by pruning treatments.
Publications
- Kovaleski, A.P., J.G. Williamson and R.L. Darnell. 2012. Vegetative and reproductive traits of southern highbush blueberry under different summer pruning systems. HortScience. 47:S327. (abstract).
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Progress 07/01/10 to 06/30/11
Outputs
OUTPUTS: Data were collected to determine the effects of pine bark soil amendment on reproductive and vegetative growth, and stem water potential of Emerald southern highbush blueberry. Preliminary results were reported at statewide blueberry grower meetings and at the annual meeting for the American Society For Horticultural Sciences. Data was collected on the effects of nitrogen fertilizer rate and form (slow versus quick release) of vegetative and reproductive growth of Emerald and Jewel southern highbush blueberry. Results were presented at the annual meeting for the American Society for Horticultural Sciences. PARTICIPANTS: Bradley Ferguson, graduate student, collected and analyzed data for the nitrogen fertilization study. Luis Mejia, graduate student, collected and analyzed data for the soil amendment study. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Soil Amendment Study. Plant canopy volumes and pruning weights were similar among the amended treatments but were less for plants in the non-amended treatment. Fruit yields for the amended treatments were similar, but yields for the non-amended treatment were consistently lower. However, total yield (summed across 2007-2009) was greater for the Incorporated plus Mulch treatment (9,477 g/plant) than for the Bed (8,037 g/plant) or the Soil (2,085 g/plant) treatments but was not different from the Incorporated treatment (8,768 g/plant). Plants under irrigated and short-term drought conditions (predawn and midday) had lower stem water potentials during fruit development in non-amended than in amended soils. Also, during short drought conditions after the summer growth flush, plants in non-amended soils had lower midday stem water potential than plants in amended soils. However, following long term drought conditions during fall, plants in non-amended soils had greater predawn stem water potentials than plants in the amended treatments. Root densities were similar for the amended soils and much greater than in the non-amended soil. Higher root densities in the amended treatments may have resulted in more efficient water uptake under short drought conditions resulting in greater midday stem water potentials. During long-term droughts, available soil moisture was probably depleted faster from the amended treatments where plant canopies were larger and root densities were higher. This resulted in lower predawn stem water potentials for the amended treatments compared with the non-amended treatment. Nitrogen fertilizer rate and form study. Effects of nitrogen rates (Low, 54.7 g/N/plant/year; Medium, 78.1 g/N/plant/year; and High, 101.5 g/N/plant/year); and nitrogen forms (slow release, sulfur coated urea (SCU) 50 percent of N plus ammonium sulfate (AS) 50 percent of N; and quick release, ammonium sulfate 100 percent of N) were evaluated for vegetative and reproductive growth of Jewel and Emerald southern highbush blueberry. For Jewel there were no effects of nitrogen rate or type on canopy volume. For Emerald plant canopy volume increased linearly with nitrogen rate for 3 of the dates measured, for the last measuring date the relationship was curvilinear. For Emerald there were no differences in berry yield in 2008 or 2009. There was a curvilinear response to nitrogen rate in 2010, but there were no differences for nitrogen type. There were no differences in berry yield of Jewel for all three years.
Publications
- Mejia, L.E., J.G. Williamson, and E.P. Miller. 2010. Plant water potential of southern highbush blueberries (Vaccinium corymbosum hybrid) grown in different pine bark amended soils. HortScience 45 (8) Supplement S 313.
- Ferguson, B. Y. and J.G. Williamson. 2010. Nitrogen rate and form affects growth and yield of southern highbush blueberry in pine bark beds. HortScience 45 (8) Supplement S 315.
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Progress 10/01/08 to 09/30/09
Outputs
OUTPUTS: Experiment 1 - Reduce pine bark, water, and fertilizer inputs. Berry yield and canopy volume were measured for southern highbush blueberry plants grown in 4 soil management systems using varying amounts and placement of pine bark (see approach for details). Experiment 2 - N fertilization of southern highbush blueberry. Fertilizer treatments consisting of three rates of N and two applications frequencies (2- week or 4-week intervals) were used to evaluate growth, yield and fruit quality of 'Emerald' and 'Jewel' southern highbush blueberry. Experiment 3 - Chill accumulation and dormancy. There was no activity to report in this area in 2009. Experiment 4 - Develop firm-fleshed cultivars suitable for mechanical harvesting. Crisp-fruited clones (FL98-325 in some cases and Sweetcrisp in others) were crossed with 20 different cultivars or advanced selections. Fruit were harvested, and the seeds were extracted, dried, and stored for planting in November (when temperatures are low enough to promote germination). One-hundred seedlings were grown from each cross, resulting in 2,000 seedlings to be evaluated in the fruiting nursery in 2011. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Experiment 1 - Reduce pine bark, water, and fertilizer inputs. Canopy volume, berry yield per bush and mean berry size (fresh weight) were greater for plants grown in pine bark amended soils than for plants grown in non-amended soils. There were no differences in canopy volume, yield per bush , or berry size among the treatments where pine bark was used (pine bark bed, incorporated pine bark or incorporated pine bark plus pine bark mulch). The incorporated pine bark system used half as much pine bark as the pine bark bed system or the incorporated pine bark plus pine bark mulch system with no reduction in plant canopy growth or berry yield. Experiment 2 - N fertilization of southern highbush blueberry. There are no outcomes to report at this time. Experiment 3 - Chill accumulation and dormancy. There are no outcomes to report at this time. Experiment 4 - Develop firm-fleshed cultivars suitable for mechanical harvesting. There are no outcomes to report at this time.
Publications
- Mejia, L.E., P. Miller and J.G. Williamson. 2009. Use of pine bark in soil management of southern highbush blueberries (Vaccinium corymbosum L.) HortScience 44: 1001. (abstract).
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