Selected pawpaw varieties for yield, flavor, and early-bearing.

1. Improved Varieties of Pawpaws
for Virginia — a new fruit crop well-suited to organic agriculture
• Virginia Association for Biological Farming, 14th Annual Conference, Feb. 8-9, 2013

2. PAWPAW
A NEW TREE CROP
FOR THE EAST
• R. Neal Peterson – The PawPaw Foundation

3. WHAT
IS A
PAWPAW
?

5. The Pawpaw Is
• Asimina triloba – Annonaceae (custard apple family)
• North America’s largest native edible fruit
• Native to 26 states in the East, Midwest & South
• Not a papaya – Brits often call papaya ‘paw paw’
• A delicious and nutritious fruit – lots of personality
• Popular once upon a time – many places named for it
• Nowadays very little known by Americans
• Recently domesticated with superior cultivars
• Is becoming a new fruit crop

6. Botany: belongs to the Annonaceae family
cousin to the cherimoya and the guanabana
which are popular fruits throughout the tropics

7. Native Range – Eaten by the Indians

8. and white settlers, too,
who named towns
and creeks after it,
… and they even sang
a song about them
“Way Down Yonder in
the Paw Paw Patch”

9. The Paw Paw Bends of the Potomac River

10. Food Qualities
• Unusual tropical flavor for a temperate fruit.
Tastes similar to cherimoya and guanabana.
Like a combination of banana, mango, pear, pineapple.
Not hard – a soft texture, custardy, avocado-like.
• Possesses great nutritional value (better than apple).
• High in calories (similar to banana).
High in minerals – K, Ca, Fe, Cu, Zn, Mn, Mg.
Protein level about 2% – high for a fruit.
A very good balance of the essential amino acids.
• High in antioxidants

11. ORCHARD INFO

12. Cultural Requirements
• Humid temperate climate, zones 5-7
• Moderately acid soils, pH 5.5 – 7.0
• Full sun for optimal yields
• Well-drained soils – no hard pan
• Ideally deep fertile soil with good organic matter
• Freedom from competing vegetation

13. Orchard Layout
• Flexible spacing
• 10 ft centers (approx)
• 18-22 ft row widths
• Machinery dictates width
• North-south rows
(usually)
• Windy sites a problem
• Wind breaks and barriers

14. Fertilization
• Similar to other fruit trees
• N important in early years
• Roughly 50 lbs of N/acre
• Extra K during harvest years
• Foliar tests for micronutrients
• Requirements probably higher
for S and Mg

15. • Necessary on ALL but
the most favorable sites
• Not necessary in normal
rainfall growing season
• Vital in drought (obvious)
Irrigation

16. Pruning
• Minimal
• Central leader
• Control height
No Ladders. Pick from
the ground level only
• Open access on sides
• Maintain shade for fruit

17. Orchard Floor
• Weed control is essential
Mulching and cultivation for organic farming.
There are no herbicides listed for pawpaw.
In practice we find that Surflan is well
tolerated. Weed control a must.
• Clean floor management
Clean up windfalls after harvest.
Old fruit harbors fungus attacking skin.
Old fruit can be used for seed to be sold to
seed companies or as biomass for
acetogenins.
• Pawpaw root suckers
Control by mowing and pruning

18. Insect Pests
• Zebra Swallowtail Butterfly
Larvae feed on young leaves, cause
slight damage, not an economic pest
• Japanese Beetles
Problem only some years, younger leaves
• Pawpaw Peduncle Borer
Larvae consume inner flower parts
and burrow down stem. The adult is
small (5-7 mm). Native w/ predators.
• Pawpaw Leaf Roller
Webs, rolls & eats leaves in late summer
• Fruit damage extremely rare

19. Fruit Pests —
Fungal & Physical
• Various fungi involved
• All superficial
• Do not penetrate flesh
• Can cause fruit cracking
• Fruit cracking / cultural
Caused by a long dry spell
followed by plentiful rain
• Sun scald a problem
But shade protects the fruit

20. the terraced
rice paddies of
southern Appalachia
are often lined or
intercropped with
pawpaws
Well, after global warming!
very compatible
for intercropping

21. HARVEST INFO

22. Flowering &
Pollination
• Flowers are perfect
male & female parts in each
• Fly & beetle pollinated
• Usually not self fertile
• Two or more cultivars
required for pollination

23. Fruit Thinning
• Some cultivars overbear.
Allegheny you must thin
• Thin to maintain size and
fleshiness.
• Thin out weak clusters.
Within a strong cluster,
thin to 1, 2 or 3 fruits.
• A few cultivars tend to 1
or 2 fruits per cluster and
require little thinning.
Shenandoah for example

24. Yields at Maturity
300 trees/acre, ~ 30 lbs/tree, ~ 4 tons/acre

25. The Harvest Season
• Ripening season in Virginia is roughly Aug.25 - Oct.1
• Length of picking from each tree is about 12-20 days
• Length varies by cultivar, some shorter, some longer.
• Cultivars are either early, middle, or late. Those with
the best fruit quality are middle and late.

26. Harvest Issues
Subtle unreliable color breaks
Each tree ripens over 2-3 weeks
• Fragile and perishable
• Picked largely by feel
• Daily picking advised
• Labor intensive

27. Packing
& Storing
• Refrigeration required
• 33º to 35ºF optimal
• Fruits packed in single
layer flats with proper
cushioning
• Picked a few days
under ripe, fruit can be
stored about 21 days
and then still finish
ripening properly at
room temperature

28. CULTIVAR INFO

29. Overview
• Too many inferior cultivars are advertised that never
should have been named and propagated
• Low quality ones are ‘Wilson’, ‘Wells’, ‘Mitchell’ …
many others. They are not worth buying. One cannot
trust catalog descriptions.
• Best of the old ones are
‘Overleese’
‘Sunflower’
‘NC-1’
‘Pennsylvania Golden’ (for earliness)

30. My Breeding Program
• Started in 1981. Ended about 1998.
• 2 orchards at the University of
Maryland experiment stations
• Orchards were planted 2 years apart
• Each orchard was roughly 750 trees
• Trees were O.P. seedlings from five
historic collections, circa 1926-1950
• Best collection turned out to be the
Blandy Experimental Farm, in VA

31. Breeding (continued)
• Seedlings took about 7 years to fruit.
• Being trees, evaluation over multiple
years is necessary. Ten years maybe?
But do I have time? I went for 3 years.
• None of the trees that looked best in
year-1 were in the top by year-3.
• Selected top 9 trees from each orchard.
• Worked with 10 universities to conduct
a RVT evaluation of pawpaw – this had
never been done – my 18 advanced
selections plus 10 known cultivars.

32. Pawpaw Regional Variety Trial

33. Preview – Best of the new
• Peterson Pawpaws
‘Wabash’, ‘Shenandoah’, ‘Allegheny’, ‘Susquehanna’,
‘Potomac’, #10-35, and others (‘Rappahannock’ not
consistent however)
• Kentucky State University
‘KSU Atwood” and several selections under observation
• Possibly ‘Mango’ ‘Green River Belle’ ‘Shawnee Trail’

34. Shenandoah
• Good yields
• Sweet mild flavor
• Fleshy - S:F ratio 6%
• Succulent, custardy texture
• Most popular at DC farmers
market
• Responds well to pruning
TM

35. Susquehanna
• Very fleshy - S:F ratio 3%
• Very sweet, rich flavor
• Firm, buttery texture
• Fruit size very large
• Moderate yields
• Responds well to pruning
TM

36. Sources of Peterson Pawpaws
• Nolin River Nut Nursery (KY)
• Forrest Keeling Nursery (MO)
• One Green World (OR)
• Heritage Seedlings (OR)
• Edible Landscaping Nursery (VA)
• Don Shadow Nursery (TN)
• I Have A Handout On These Nurseries With Contact Info

37. MARKET INFO

38. Approaches to marketing pawpaws
• Absolutely vital for the commercial grower
• Pawpaws are unknown to 98% of US consumers
• Education is basic to gaining a customer following
• At this time best outlets are farmers markets –
urban or at the farm itself
• Restaurants are another possibility (w/ problems)
• Some processed products have real potential

39. Pricing
• Must be high to cover
harvest costs
• In San Francisco they sell
for $5/lb and they aren’t
even named varieties
• When I sold in DC for 3
years at the Dupont Circle
Farmers Market, I sold my
named varieties for $5/lb
• In smaller town farmers
markets, price about $3/lb

40. Consumer Education
• Consumer education is a must in order to sell this new fruit.
• Samples! Few people know pawpaw, are fearful, hesitate to buy.
• Also, information sheets and recipes

41. Market Outlets …………….……
Farmers markets, gourmet restaurants, etc

42. Mechanized Processing ?
Very important to extend the market season.
Makes excellent ice cream. Processing not yet realized.

43. ORGANIZATIONS
• The PawPaw Foundation – since 1988
Public outreach, education, stimulation of interest & research
• Ohio Pawpaw Growers Association – new in 2008
Production & marketing issues, is now national in scope
• Kentucky State University – since 1992
Only full time research program – Dr. Kirk Pomper
• Ohio Pawpaw Festival – since 1998
Held annually near Athens, OH

44. KSU Research
Dr. Kirk Pomper
• Germ plasm repository
• DNA analysis
• Regional variety trials
• Seed propagation
• Root stock trials
• Acetogenin analysis
• Cultivar breeding
• Species hybrids

45. Primary Research Needs
• Efficient mechanical processing methods
• Cultivars with thicker skins, less perishable
• Breeding for reliable color break
• Identify superior root stock
• Tissue culture propagation
• Acetogenins as possible anti-cancer compound
• Acetogenins as possible health risk (Parkinsonism)

46. Primary development needs
• More growers to meet demand
• Mail order fruit from one orchard is sent nationwide
• A few wineries need source of fruit
• Creameries making ice cream need pulp
• People in DC and elsewhere are calling to ask what
market carries the fruit

47. We Need Growers – Contact Me
• The End