Blueberry Field Day July 12, 2010
3 Major Types of Commercial Blueberries Lowbush eastern provinces of Canada & northeastern U. S. Rabbiteye southeastern U. S. Highbush major cultivated species in North America Northern highbush Southern highbush
Blueberry Production Time to 1 st crop ~ 3 years Time to full production ~ 8 years Yield @ full production ~ 12 gallons /plant Expected productive life ~ 25+ years Harvest period - Highbush early June to early July Rabbiteye early July to mid August Major production problem soil ph maintenance Major pest - birds
Blueberry Production Timeline -1 year +1 year +2 years +3 years Preplant Site Preparation Defruit 1st crop rabbiteye Planting
Components of a Desirable Site Full sun Elevation (frost & disease protection) Soils: ph 4.8 to 5.2 High organic matter content Well-drained (internal & surface) Min. of 30 36 rooting depth Moderate fertility Available water supply
Preplant Site Preparation Begin at least 1 year before planting Soil test (ph, P, K, Ca, Mg) Amend & retest 6 mos. later Control noxious weeds Remove barriers to good air flow If soil drainage is marginal: Find a new site Tile drainage Raised beds (4 ft. wide X 9 12 inches high)
Planting Design If possible, run rows north to south (slope of field may dictate otherwise) Plan for cross-pollination Bloom times overlap Essential for rabbiteye, desirable for highbush Within row (about every 5 th plant, stagger ) Separate rows (every 3 rd row)
Plan for cross-pollination Bloom times overlap Essential for rabbiteye, desirable for highbush So not rely on highbush to cross pollinate rabbiteye Within row (about every 6 th plant, stagger ) Separate rows (every 3 rd row) TTTTTCTTTTTCTTTTTCTTTTT TTCTTTTTCTTTTTCTTTTTCTT TTTTTCTTTTTCTTTTTCTTTTT TTCTTTTTCTTTTTCTTTTTCTT VVVVVVVVVVVVVVVVVVVV PPPPPPPPPPPPPPPPPPPPPP VVVVVVVVVVVVVVVVVVVV VVVVVVVVVVVVVVVVVVVV PPPPPPPPPPPPPPPPPPPPPP VVVVVVVVVVVVVVVVVVVV VVVVVVVVVVVVVVVVVVVV PPPPPPPPPPPPPPPPPPPPPP
Mature, Dormant Blueberry Bush
Floor Management Permanent sod between rows Serves as a deceleration and diffusion strip for runoff water Support for equipment Mulching down the row Suppresses weeds Moderates moisture & temperature
Mulches: Increased survival Increased growth Especially with Black Fabric & Organic/Black Maintained more uniform moisture levels in the root zone Reduced temperature fluctuations in the root zone Increased yields
Canopy Vol. (ft³) by Tmt & Year 60 50 40 30 20 10 No Mulch Organic Black Black + Org White 0 2001 2002 2003
Avg Soil Moisture Jul 01 0.00-5.00 182.00 182.63 183.25 183.88 184.50 185.13 185.75 186.38 187.00 187.63 188.25 188.88 189.50 190.13 190.75 191.38 192.00 192.63 193.25 193.88 194.50 195.13 195.75 196.38 197.00 197.63 198.25 198.88 199.50 200.13 200.75 201.38 202.00 202.63 203.25 203.88 204.50 205.13 205.75 206.38 207.00 207.63 208.25 208.88 209.50 210.13 210.75 211.38 212.00 212.63 Matric Potential, kpa or cb -10.00-15.00-20.00-25.00 Black Organic -30.00-35.00-40.00 No Mulch -45.00-50.00 Julian Day
Degrees Celsius 30 29 28 27 26 25 24 23 22 21 20 Effect of Mulches on Soil Temperature Bare Organic Black Black +Org White Midnight 6:00 AM Noon 6:00 PM Time, Aug. 1, 2004 11:00 PM
Determining Nutritional Needs: Postplant Soil testing Tissue analysis Growth & fruiting Past experience
Blueberry Nitrogen Fertilization Multiple applications Young plants: every 4 6 weeks (bud break to early Aug.) Mature plants: 2 to 3 applications of N (30 # N/A/ application*) 1 st at bud break Last after harvest * For 12 ft. between row spacing
Pruning Nonbearing Blueberry Plants At planting: Remove weak shoots Cut shoots back to ½ of original length Remove fruit buds 1 st Dormant Pruning: Remove fruit buds Remove weaker, shorter shoots at the base of plants
Why Prune? Remove dead, diseased wood Control plant size Remove older, less productive wood Encourage development of new wood for future crops Increase sunlight penetration throughout plant canopy Fruit bud formation Fruit color, sugar development
Pruning Mature Blueberry Plants Remove weak, shaded, lower shoots Prune plants to 4 5 ft. in height and width Highbush varieties > 5 yrs. old: remove 20% of canes/yr Rabbiteye varieties > 6 yrs. old: remove 10 15% of the canes/yr. During growing season top vigorous canes at 4-5 ft.
Why Control Wildlife in Fruit Crops? Economic losses Fruit destroyed or consumed by wildlife Increased disease & insect pressure with damaged fruit Damage to plants and cropping system Feeding on succulent shoots Girdling or rubbing on plants Puncturing plastic Food Safety
Wildlife Damage Prevention Categories Habitat modification Remove roosting, nesting sites near planting Scare devices (visual & auditory) Repellents (taste & smell) Removal Shooting Exclusion (netting)
Wildlife Damage Prevention Categories Habitat modification Exclusion Fencing Netting Scare devices (visual & auditory) Repellents (taste & smell) Removal trapping shooting
Blueberry Fruit Losses to Birds Bluecrop 100% crop loss with unnetted plants 5 pints / bush yield X $1.99/pint = $9.95 loss / plant X 726 plants / acre = $7,223.70 lost / acre Tifblue - 60% crop loss with unnetted bushes 10 pints/plant yield total Loss of 6 pints / plant to birds X $1.99 / pint = $11.94 lost / plant 726 plants / acre X $11.94 lost / plant = $8,668 lost to birds/acre