New Innovations in Pumpkins

Brent Loy Biological Sciences University of New Hampshire

Major Program at NHAES since 1985 on breeding Jack-o’-lantern pumpkins.

Pumpkin Varieties Released From NHAES Varieties Female Big Rock UNH Champion UNH Chucky UNH Cider Jack (PMT) UNH Gold Challenger UNH Gold Fever UNH Gold Standard UNH Gold Medal UNH Cougar Hollar Hannibal UNH Hybrid Pam UNH 20 Karat Gold UNH Moonshine UNH Neon UNH Prankster (PMT) UNH Or Smoothie (AAS) UNH Pik-a-Pie UNH Racer UNH Snackface UNH Snackjack UNH Solid Gold UNH Trickster UNH

Male JSS JSS HSNZ UNH UNH Rupp Rupp Rupp UNH HSNZ SEM Rupp UNH UNH UNH UNH UNH JSS UNH UNH Rupp SEM

Vendors

Producers

Johnny’s (JSS) Siegers, JSS High Mowing Org Rupp, Siegers Rupp Rupp Rupp, JO, HA, SI SeedWay Siegers, Stokes Rupp, HA, JO, SW, SI Rupp, Siegers JSS, SW, ST, SI HA,JO,RU,ST,SW Rupp, JO, HA, SI JSS, RU, ST, SI Rupp, SI Johnny’s

JSS HSNZ HMOS Rupp Rupp Rupp Rupp Hollar HSNZ SEM Rupp HSNZ Hollar Rupp SEM Rupp JSS

Rupp JO, RU, ST, SW

Rupp SEM

SW= Seedway; HA = Harris Seeds; ST = Stokes; JO = Jordan; SI = Siegers; SEM = Seminis

Getting a Handle on Pumpkin Varieties

Brent Loy and Melanie Berg Department of Plant Biology University of New Hampshire

Strong and long enough to carry by handle.

What Makes a Good Stem? Reasonably robust for size of pumpkin. Orange Smoothie

Does not shrivel following harvest.

Autumn Pride Farm, 2013: 15% of pumpkins considered unmarketable because of handle shrivel following harvest.

How do you insure a good handle on a pumpkin?

1. Starts with variety selection. 2. Establish a good leaf canopy prior to fruit set. 3. Maintain leaf canopy until at least 30 to 35 days after fruit set.

Dry Weight (g)

Leaf canopy and fruit development in semi-bush pumpkin. 180 160 140 120 100 80 60 40 20 0

Leaf blades Pericarp Seed

-20 -10 0

12 25 35 45 55

Days from Pollination

Yearly variation in photosynthetic capacity of plant can affect stem integrity.

Variety 2002 Orange Smoothie Racer Jackpot 2003 Orange Smoothie Racer Jackpot

% DW Flesh

% DW Peduncle

% stem Shrivel

6.2 14.6 19.7

11.5 9.6 9.0

22.4 16.3 14.8

19.5 54.8 62.9

5.3 14.3 22.0

9.0 7.8 6.3

17.0 13.9 13.1

44.8 72.4 71.2

Fruit wt.

% mesocarp DW at 30 DAP; % peduncle DW and shrivel at 40 DAP.

Fruit Growth In Pumpkin 40

Fruit Circumference (inches)

Hybrid Pam Autumn King 35 30 25 20

Color change

15 10 15

20

25 30 Days After Pollination

35

40

When Do Handles Reach Maximum Strength Treatment

Fr. Wt. %DW % Shrivel

Racer 1. Harvest at 35 DAP 2. Harvest at 55 DAP 3. Defoliate 35 DAP; harvest 55 DAP

15.6 15.4 16.5

16.4 14.9 14.9

49.2 41.2 40.6

NS

NS

NS

5.7 6.2 6.2

18.3 18.6 72.3

22.4 16.4 1.6

NS

NS

NS

LSD0.05

Orange Smoothie 1. Harvest at 35 DAP 2. Harvest at 55 DAP 3. Defoliate 35 DAP; harvest 55 DAP LDS0.05

Stages of Pumpkin Development Days After Pollination (DAP) 0 – 25 DAP fruit growth 10 – 35 DAP accumulation of flesh dry matter (starch) 10 – 40 DAP accumulation of stem dry matter (cellulose + lignin) 25 – 40 DAP rind color changes (loss of chlorophyll) 25 – 55 DAP accumulation of seed reserves (proteins and lipids)

2013 Hybrid Pumpkin Variety Trial Kingman Research Farm, Madbury, NH

15 Commercial hybrids: Gladiator, Magic Wand, Spartan, PMR Challenger, Cougar, Mustang, Diablo, Solid Gold, Gold Challenger, PMR Racer, Mystic Plus, Prankster, Lil’ October, Wee-Be-Little, and Moonshine. 88 Experimental hybrids (all with PMR): 14 – yellow and white color class 8 – small pumpkin class 66 – medium to large jack-o’-lantern pumpkins (11 to 30 pounds)

Pumpkin Rating 1. Poor – example would be Connecticut Field op 2.

Fair – decent color, most handles shrivel or break easily.

3. Good – excessive shrivel or 30% or more breakage. 4. Very good – good color, ribbing, handle length, most (70 to 80% handles reasonably sturdy and don’t shrivel. 5. Excellent – all handles very strong and no shrivel

NH4729

NH4716

NH4727

NH4736

NH4717

NH4713

NH4796

NH4781

NH4736

NH5720

NH4797

Gladiator

NH4716

NH4794

Future Improvements to Standard Orange Ornamental Pumpkins Disease resistance – Plectosporium? Phytophora? others Pumpkin density – flesh depth versus circumference. sell by pumpkin – less density; more fruit per plot. wholesale: less weight per fruit – lower shipping costs. sell by pound – thick flesh = heavier pumpkin

Gladiator

NH4782

NH4716

NH4736

-Novelty PumpkinsNew and Future Introductions

Moonshine

New Introduction – ‘Sunlight’

Siegers Seeds

Acknowledgements Dean’s Office

Farm Assistance

Greenhouse

Dean Jon Wraith Dr. Anita Klein

Mng. John McLean Assist. Evan Ford

Mng. David Goudreault Assist. Jonathan Eb

Research Technicians

Research Assistants

Hua Cui Elizabeth Whelton

Jake Uretsky Kaitlyn Orde

Happy Holidays

Pumpkin Innovations During the Last Two Decades • Bush gene incorporated into most modern varieties. • Cultural change to closer row and within-row spacing. • Powdery mildew tolerance (PMR or PMT) added to many varieties. • Enhanced color and in many instances better handle (peduncle) strength.

“Growth habit” is a major consideration in variety selection Vining habit Greater weed pressure before leaf canopy closure More immature fruit at harvest Tolerate environmental stresses well Can support mammoth pumpkins Semi-bush or bush habit Convenient seed production from bush x vine cross More uniform plant and fruit size Faster leaf canopy closure & better weed control Not as tolerant of environmental stress as vine varieties

Vine Pumpkin on Mulch

Semi-bush hybrid – 3.5 weeks

Semi-bush hybrid – 5 weeks

Semi-bush hybrid, 7 weeks

Primary Attributes of New UNH Varieties • Tolerance to powdery mildew. • More consistently strong stems which do not shrivel late in the season under reasonable growing conditions. • Varieties with both early season and midseason maturation. • Varieties with improved orange coloration and some different rind colors (white, yellow, striped)

Advantages of Powdery Mildew Tolerance • Fewer spray applications required. • Greater photosynthetic capacity during critical fruit growth period: – Fruit set period to about 25 days after fruit set (Late July - August)

• Adequate photosynthate storage in fruit mesocarp assures development of strong handles (in good varieties).

White C. pepo Pumpkin with Robust Handle

Tentative 2014 Introduction PMR Moonshine (other possible PMR White)

NH4716 – Medium Size with PMR

NH4727 Early Maturing PMR Hybrid

NH4781, 5720, 4736, 4782

Woody, heavily lignified stem that does not shrink after harvest.

Robust stem, flared at base for strong attachment.

Black Stem (D gene)

What management practices help insure the best possible handle? Need to Know Facts about Pumpkin Development When do pumpkins grow? When do pumpkins mature? When do stems reach maturation? When do pumpkins fully ripen?

% Dry Matter - Pumpkin Mesocarp 14

% Mesocarp DM

12 10 8 6 OrSm Racer Jackpot

4 2 0 20

30 40 Days After Pollination

60

% Dry matter of Stems Contributes to Stem Strenth in Ornamental Pumpkins

• High cellulose • High lignin – woody properties • Low pectin content

Pumpkin stems stained for presence of lignin. Orange Smoothie 20 Day

60 Day

Jackpot 20 Day

60 Day

Fresh stem, Orange Smoothie, 40 DAP

Dried stem, Orange Smoothie, 40 DAP

Fresh stem, Hybrid Pam 40 DAP

Dried stem, Hybrid Pam, 40 DAP

Stems will remain dark green if the vines are healthy, but stems turn brown once pumpkins are harvested.

How do you keep handles green?

Conclusions • • • • •

Handles reach peak dry matter about 30 to 40 days from pollination Near full skin color is a good indicator of peak stem dry matter. Some varieties color late, and stems of these varieties seem to harden late. Harvest pumpkins before vines die. Handles remain green when left on vines that have not senesced.

Acknowledgements

Susan Clark

Melanie Berg

Hua Cui

The End

‘Orange Blossom’ Johnny’s Selected Seed

Glabrous Summer Squash Hybrid

Jackpot 20 DAP

Orange Smoothie 20 DAP

OS 60 DAP

JP 60 DAP

Semi-bush hybrid – 5 weeks

Vine Pumpkin on Mulch

Changes in Mesocarp Dry Matter 10

% Mesocarp Dry Matter

9 8 7 6 5 4

OrSm Racer Jackpot

3 2 1 0 20

30

40

60

Days After Pollination

12

60

3

10

50

Fruit FW (kg)

2.5 8 2 6 1.5 Embryo DW

4

1

% Mesocarp DW

3.5

44

30

20

Fruit FW 0.5

2

10

0

0

% DM Fr

0 10

20

30

40

Days after anthesis

50

60

Embryo DM (g)

Fruit Growth and Mesocarp Dry Matter In Relation to Seed Development

Pumpkin attached to green vine

PMT Pumpkin hybrid, 1747 (Rupp Seeds)