Blueberries and Blueberry Biology

Paul Lyrene , Plant Breeding Professor (retired); Horticultural Sciences Department, University of Florida IFAS, Gainesville, FL Talk Outline

• Growing back-yard blueberries in Sarasota County • Blueberry biology and ecology • Commercial blueberry production worldwide • Other potential back-yard fruit crops for this area

Growing a few blueberries in your back yard in Sarasota • Recommended varieties: Emerald, Jewel, Sharpblue, Kestrel, Snowchaser, Flicker; Plant two or more varieties for cross-pollination • Acid soils, pH below 5.5, good drainage, often planted on beds of soil mixed with Canadian peat. • pH can be lowered with elemental sulfur (1 Lb per 100 square feet) • Low-pH irrigation water –rain barrel water • Full sun to partial shade, far from the roots of broadleaf trees (farther than the tree is tall). • Mulch with pine straw (or pine bark) • Fertilize lightly 6 times/year during growing season • Let the birds eat the fruit or put on a light net • Plants flower in February, ripen April and May Blueberry Classification

• Family: Ericaceae: Vaccinium = blueberries; Gaylussacia = huckleberries; Erica = Heath, Rhododendron, Lyonia, Mountain laurel, • Genus Vaccinium: 400 species worldwide; all make edible berries. • Center of origin of Vaccinium: tropical highlands • Center of origin of section Cyanococcus, the blueberries most important in world agriculture: eastern North America Vaccinium species important in world commerce: • Section Cyanococcus blueberries: Lowbush, highbush, and rabbiteye blueberries: native in eastern North America • Cranberries: Wisconsin, Mass. (Native in eastern North America) • Lingonberry: Sweden, Norway, Russia, Alaska • Bilberry: northern Europe, Alaska, Canada- gathered from the forest; valued for tart, intensely blue flesh Bilberry and Lingonberry forest, Norway Fruit market with bilberry, Bergen, Norway

Some blueberry biology

• The 400 species of blueberries existing today are all descendants of one species that lived about 50 million years ago in mountainous areas north of Australia • The various groups of blueberries (cranberries, lingonberries, bilberries, sparkleberries, deerberries, section Cyanococcus blueberries) represent different evolutionary branches from the original species. • Each of these branches has many sub-branches Section Cyanococcus blueberries

• Originally found only in eastern North America • Includes three commercially-important groups: lowbush blueberries of NE U.S. and S.E. Canada; rabbiteye blueberry from north Florida; highbush blueberry native from Lake Okeechobee to Nova Scotia • Also contains 20 wild species, 7 of which occur naturally in Florida • Despite greatly different appearances, many of the section Cyanococcus blueberries can be hybridized to make perfectly-fertile offspring • This fact has allowed breeders to develop cultivars with a wide range of adaptations and characteristics Vaccinium darrowii: Florida native lowbush blueberry

North-South Adaptation of native Vaccinium corymbosum • Many woody plants that are native in eastern North America have a long north-south range (Highbush blueberry, red maple, red mulberry, dogwood, persimmon, hackberry). • A plant from New Jersey will not grow in Florida even if the same species is native in Florida. • Differences in chilling requirement are one important reason, but are only the tip of the adaptational iceberg. • Highbush blueberries from New Jersey are deciduous and have a high chilling requirement. • Highbush blueberries from Highlands County Florida are almost evergreen and have no chilling requirement.

Blueberry Reproduction

• Most woody plants are cross-pollinated; they have various methods of preventing close inbreeding. • Some are dioecious (holly, wax myrtle, eastern redcedar), some are monoecious (oaks, hickory, pines), some have perfect flowers but are self incompatible. • Wild blueberries have perfect flowers but are self-incompatible. • Cultivars are somewhat more self-fertile but it is best to mix two or more varieties

Blueberry propagation Methods:

• Seeds, division, stem cuttings, root cuttings, in-vitro tissue cultures, grafting • Blueberries of almost every species are extremely easy to grow from seed but almost nobody can do it. • Commercial blueberry varieties do not come true to seed, but most seedlings are quite good.

Breeding new blueberry cultivars

• The fact that blueberries grown from seed are extremely variable is the key to breeding new varieties. • If you choose the best seedling and propagate it with cuttings, it retains its superiority. • The task of the breeder is to breed better parents so that when they are crossed, they produce seedlings of exceptionally high quality. Getting better parents by recurrent selection: This is the key to all plant breeding • Start with the 200 best plants you can find • Use them to make 100 crosses • Grow 100 seedlings from each cross, and from the 10,000 seedlings, chose the best 200 plants. • Repeat, repeat, repeat, repeat……… History of Blueberry Production

• Blueberries were gathered from the forest by native Americans • 1893-1940: 2000 acres of rabbiteye blueberries planted in north Florida using wild plants dug from the Yellow River in west Florida • 1916 First improved highbush blueberry varieties released by USDA for New Jersey • 1948 Ralph Sharpe began breeding Florida- adapted highbush blueberries for Florida

• 1976: first low-chill highbush cultivars released from UF: Sharpblue and Flordablue • 1983: first year fresh blueberries were available in NYC earlier than May 20. Florida grower got $5 per pound compared to 50 cents for pick-your-own • $70 million per year: current value of Florida blueberry crop World Production of Highbush blueberries 1977: 120 million pounds, 95% from North America 38 Years later:

2015: 1,200 million pounds, 50% from North America Reasons for growth in Blueberry production • New varieties and production in southern hemisphere extended the season; formerly May 20 to August 20, now 365 days of the year. • Blueberries are popular with consumers: easy to eat, health benefits • Harvest and packinghouse advancements • Long post-harvest life New Project: Breeding deerberries

• Deerberries (Vaccinium stamineum) are native throughout most of Florida • They have large fruit, high yields, potentially good flavor, grow well on scrubland and high pine land (Rosemary and Turkey oak land) • They have never been domesticated • Why? Bitter fruit, hard to propagate true-to- type • The main reason: nobody has worked on them

Other possible fruits for Florida

• Greening-tolerant citrus: • Mandarin: Fall Glow and Sugarbelle • Grapefruit: Jackson and Triumph • Kumquat: grafted on to Poncirus rootstock Figs

• Variety: Brown Turkey • Plant near cement foundation • Mulch heavily with pinestraw • Fertilize and water lots • Fruit ripe July and August

• Black Mulberries: get a low-chill variety Strawberries

• Plant in October • Harvest December through May Japanese Persimmon

• Various astringent and nonastringent varieties • Tanenashi, Fuyu and others • Grafted onto native American rootstock, Diospyros virginiana Blackberries and Raspberries

• Ocklawaha and Florida Grand dewberries • Brazos and Tupe blackberries • Mysore tropical black raspberry Apples

• Anna and Dorsett Golden • Squirrels and summer fruit rot Other Potential Crops

• Banana: Dwarf Cavendish • Pineapples: racoons love them • Avocadoes: Laurel wilt an impending problem • Grapes: google: edis.ifas.ufl.edu • Jujube: Zizyphus jujuba Chinese Jujube: Zizyphus jujuba