(See also the separate file Zucchini and Summer Squash)
Many excellent varieties exist. Only a selected few are listed below.
See also the section "Harvesting, Handling, and Storage" for expected yields and size descriptions.
For decorative purposes and Halloween, pumpkins from 8 to 18 lb are preferred. Larger
pumpkins are valued for individual display purposes, and smaller ones are usually used in
ornamental arrangements.
Production in eastern Oregon and in the Columbia Basin may be limited by
curly top and other viruses. Select sites that are surrounded by crops where insects are
controlled, and which are distant from open range, as this will minimize exposure to leafhopper vectors.
Since vine crops are also sensitive to damage from wind, select protected sites and use
windbreaks (see WINDBREAKS section below).
There is much confusion with regard to the use of the words "pumpkin"
and "squash". The words have been used indiscriminately by growers, consumers and the seed industry.
These words refer to culinary traits rather than taxonomic classifications.
Pumpkins are considered to be drier, coarser, and strong-flavored
compared to squash and are therefore used differently in cooking. "Pumpkin" should be used to define
edible fruit of any species of Cucurbita utilized when ripe in
pies, and not generally served as a baked vegetable. The term "pumpkin" is also associated with the Halloween
Jack-O-Lantern, and refers to fruit of any Cucurbita species (usually orange-skinned)
used for that purpose.
Squash is usually divided into two categories:
"Summer squash" should be used to refer to the edible fruit of any
Cucurbita species (commonly C. pepo) used when immature
as a table vegetable.
"Winter squash" should refer to the edible fruit of any species of
Cucurbita, utilized when ripe, as a table vegetable or in pies, the
flesh of which is fine grained, mild flavored, and suitable for baking.
"Winter squash" is also the term used to refer to Cucurbita fruit that
is stored into the late fall or winter months. Examples would be all
baking varieties of C. maxima, and the cushaw forms of
C. moschata which are used when mature, and for certain
varieties of C. pepo used when mature (e.g. Acorn, Table Queen)
and of C. moschata (e.g. Butternut).
For other characteristics that are used to differentiate Cucurbita
species, see the appropriate section below.
See also Cucurbits
Genetics Cooperative Home Page--a service for those interested in the genetics
and breeding of cucurbits.
PUMPKIN VARIETIES
Varieties of pumpkins are listed from smallest to largest fruit.
Approximate days to harvest are given for the Willamette Valley; for warmer areas, subtract 10-15 days.
Miniature, decorative pumpkins, less than 1-lb fruit, (approximately 95
days). Although used primarily for ornamental purposes, these are also suited for baking:
Sweetie Pie, and Jack Be Little 3x2 inches; also Small Sugar and Mini Jack
Munchkin, 3X4 inches. White-skinned miniature: Baby Boo 3x2 inches.
Small, decorative specialty varieties (1-5 lb; approximately 105 days):
Baby Bear (6x4 in. and 1.5 to 2.5 lb), Mini-Jack (both hulless or
naked-seeded); Oz, Spooktacular (both 5 inch round, uniform); Spookie, Baby Pam (both about 5X6
inches); Little Lantern (early, about 5X4 inches)
Small to medium (5-10 lb; approximately 110 days):
Triple Treat (hulless seed, fine-textured, orange-flesh, Jack O' Lantern-type fruit, concentrated
maturity); Spirit (early, semi-bush hybrid, medium fruit); Jack O'Lantern (open pollinated, medium
fruit); Spookie; Autumn Gold (early coloring, 7 to 10-lb, golden-yellow when immature, turning to glossy orange at maturity).
Medium to large (10-25 lb; approximately 120 days):
Howden and Kentucky Field (the classic pumpkin varieties, medium to
large fruit. Howden has attractive deep orange skin and dark green stem); Jack Pot, Wizzard, and Oz (three compact-vine
hybrids - medium large fruit); Connecticut Field, Happy Jack, Jumpin Jack, Pankow's Field (large
stems), Big Autumn, Aspen, Buckskin (especially for processing, earlier than Kentucky Field). For
trial: Bushkin (a compact bush), Howden Biggie. White pumpkin: Lumina
When pumpkins or winter squash are grown for processing for pie filling or baby food,
etc., the processor specifies
varieties. Proprietary varieties developed by the processor are similar to
Dickenson pumpkin (C.
moschata, which tends to be too late for western Oregon production), or
Golden Delicious squash (C. maxima). Others may use seed blends of Golden Delicious and
Boston Marrow, usually in 60:40 ratio, to plant fields for processing.
When pumpkin or squash is grown for confectionery seed, the seed processor determines the variety to be used.
The most commonly used is 'Golden Delicious' squash and proprietary selections of that type. Plant spacings are reduced and
plant populations are increased to produce more seed per acre. Fruit size becomes a secondary concern.
Mammoth varieties (100 + lb) "pumpkins": Big Max,
Big Moon, Prizewinner Hybrid, and Atlantic Giant (patented by Howard Dill).
Note: A number of Giant Pumpkin "clubs" exist across the U.S.A.
Members engage in exchange of seeds of hybrids they make. The Associations award prizes for the
largest pumpkins grown regionally. For $10.00 you can join the Pacific Northwest Pumpkin
Growers Assoc. Write c/o Tallina George, 15790 S.E. Hwy. 224, Clackamas, OR 97015. The 1993 Oregon
record was 727 lbs. grown by Kirk Mombert of Harrisburg, OR. Also, the World Pumpkin
Confederation, 14050 Gowanda Road, Collins, N.Y. 14034, holds annual weigh-off contests in
the U.S. and Canada and awards cash prizes for the largest, pumpkin, watermelon and squash.
For $15.00, you can join and receive their quarterly newsletter. The 1993 record was 884
lb. In 1994, a number of entries exceeded 900 lb with at least one over 990 lb. The
longstanding prize of $10,000 for the person that grows the first pumpkin over 1,000 lb was
officially given on October 5, 1996, for a 1061-lb pumpkin produced by Paula
and Nathan Zehr of Lowville, N.Y. A pumpkin grown in Canada also broke the
1,000 mark at 1,006 lb. Both were of the Atlantic Giant variety. See also
the World
Class Giant Pumpkins and Giant Gourd Growing Contest.
Naked-seeded or hulless varieties (approximately 110 days). Seed is used for roasting:
Trick or Treat; Triple Treat (round, 10-inch diam., may be used for
Halloween pumpkin, seed roasting, and pumpkin pie); Lady Godiva (grown only for its seed), both compact
and indeterminate vine types are available.
WINTER SQUASH VARIETIES:
Among winter squash varieties, only Butternut and Golden Delicious are used
for processing. Fruit quality is related to increased days to harvest
provided vines are healthy and fruit is not subjected to extended cold or
freezing temperatures. Varieties are listed by type. Approximate days to harvest, for good
quality, are given for the Willamette Valley; for warmer areas, subtract 10-15 days. Fruit quality is
related with increased days to harvest provided vines are healthy and fruit is not subjected to
extended cold or freezing temperatures.
Acorn (approximately 110 days): Green: Table Ace, Table
Queen. For trial: Tay Belle, Royal Acorn, Unicorn.
Yellow: Table Gold.
Banana (approximately 120 days): Pink Banana, Pink Banana Jumbo. For trial:
Blue Banana.
Butternut (approximately 120 days): Butternut Supreme, Early Butternut, Waltham
Butternut. For trial: Butter Bush, Hercules, Ultra Butternut (a very large butternut suitable for processing),
Nicklow's Delight ZYMV (ZYMV and CMV resistant, semi-bush hybrid), Ponka, Neck Pumpkin (long neck).
Buttercup (approximately 115 days): Sweet Mama, Buttercup Burgess
Strain.
Orange-skinned buttercup type: Gold Nuggett. For trial: All Seasons F1(orange);
Butter Boy (red-orange);
Kabocha: Kabocha is the generic Japanese word for squash, but
refers most commonly to a
squash of the buttercup type: Delica (also known as Ebisu in Japan, is one of
the most common varieties), Kurinishiki F1, Honey Delight,
Sweet Mama. For trial:
First Taste, Home Delite, Imperial Delite, Supreme Delite, Sweet Meat.
Delicata (or sweet potato squash; approximately 110 days): Sugar
Loaf, Honey Boat, Delicata.
Delicious (approximately 115 days): Golden Delicious, N.K. 530,
N.K. 580 (all having the
red-orange, tender, rind required in processing squash and thick orange-yellow
flesh; N.K. 580 is
the largest). Green Delicious (green rind).
Hubbard (approximately 120 days): True Hubbard, Blue Hubbard,
Golden Hubbard, Baby
Hubbard, Warted Hubbard, Red Kuri (also called Baby Red Hubbard or Orange
Hokkaido), Uchiki Kuri (orange-red).
Spaghetti (C. pepo; approximately 100 days): Vegetable
Spaghetti, Pasta F1, Tivoli F1 (bush
spaghetti), Orangetti (orange rind and flesh, higher in vitamin A than
Vegetable Spaghetti). These
are used as spaghetti substitute. These have become popular and much more
common in the
marketplace recently.
ORIENTAL VINE CROPS:
Vegetable Sponge, Dish-cloth gourd, Sponge gourd (Luffa sp.;
approximately 120 days). These
may be used for cooking when immature, or allowed to mature for the fibrous
spongy tissue:
Angular types (Luffa acutangula): San-C, Ping-Ann. Cylindrical types
(Luffa aegyptica):
Cylinder, Seven Star, Seven Beauty. These produce higher quality sponge
fiber.
For more information on Luffa, see the North Carolina State University file
Commercial Luffa Sponge Gourd Production.
Wax gourd (Benincasa hispida; approximately 125 days): Green
Tiger, Cheerer. Both are late,
needing a long season and hot temperatures.
Bitter melon or Balsam Pear, Bitter cucumber, Bitter gourd
(Momordica charantia) see Oriental
seed catalogs for variety availability under one or more of the above
names.
American Indian pumpkins and squash:
An unusual collection of varieties of C. maxima, C. mixta,
C. moschata and C. pepo is offered by
Gleckler's Seedmen, a company that deals with unusual seed specialties (see
address below).
Seeds of Hopi, Shawnee, Omaha, Pueblo, Cochiti and other American Indian as
well as Mexican
Zapotec and Calabaza varieties are listed. These would be best suited in the
warmer, longer
season areas of the Snake and Columbia River valleys.
Calabaza (Cuban pumpkin C. moschata; approximately 130 days):
A subtropical (but may
mature in the warmer areas of Oregon). Fruit is of high quality, 5-7 pounds,
slightly flattened at
top and bottom, mottled green or yellow and tan. Flesh light yellow. Long
vining plant. Leaves
are mottled, gray-green. Used primarily by Hispanics: La Primera, Marian Van
Atta's.
ORNAMENTAL SQUASH AND GOURDS:
Turban C. maxima (approximately 115 days): Turk's Turban,
Tiny Turk.
Gourds (ornamental, yellow-flowered C. pepo; approximately
100 days): Bi-Colored Pear,
Apple, Nest Egg, Crown of Thorns, Yellow Warted, Small Orange, Flat Striped,
Miniature Stripe,
Pear Stripe.
Bottle, Dipper etc., Lagenaria species (approximately 125
days), white-flowered: Bird House,
Bottle, Calabash, Cave Man's Club, Dipper; Italian Edible (also called
Cucuzzi, may be eaten
when immature, makes a nice rattle when mature and dried, resembles a bowling
pin but rounded
at the bottom). Trichosanthes anguina Snake gourd. These are all quite
late. Note: Some
varieties of "gourds" are not palatable when mature.
Note: For more information on gourds, contact the
American Gourd Society, POB 274, Mt. Gilead OH 43338
CHARACTERISTICS DIFFERENTIATING SOME COMMON CULTIVATED
CUCURBITA
SPECIES
Species Foliage Stems Fruit stalk Seed margin
C. pepo Spiculate Hard angular Hard, angular Smooth
(zucchini and all (spiney) ridged
summer squash; acorn;
small,colored gourds;
spaghetti squash;
Connecticut Field;
Jackolantern; ridged
orange skin).
C. maxima Moderately Soft, round Soft, round, Smooth
(Hubbard, Banana, spiculate enlarged by
Delicious cork tissue
C. moschata Non - Moderately Hard, smoothly Scalloped
(butternut, Ken- spiculate hard, angular,
tucky Field, Dic- smoothly flared
kenson; smooth orange- angled
brown skin), Calabaza
Note: Vine crops of many
other genera and species of the family
Cucurbitaceae exist and are
grown commercially, but to a lesser extent than those described above.
SEED AND SEED TREATMENT
In western Oregon, pumpkins and winter squash are planted from early to
mid May. Some early varieties and acorn squash may be planted to mid June.
Pumpkins and squash in the species C. pepo have seed numbering
approximately 100-300 per
ounce. Those in C. moschata and C. maxima have seeds numbering
approximately 200-400 per
ounce. Use fungicide-treated seed. Pumpkin and Squash seedlings are
susceptible to damping-off and decay when soils are cool and wet.
SOILS AND SITE SELECTION
Choose light, well-drained soils for earliest crops and reduced risk of
stand establishment problems. Avoid using fields in your rotation in which muskmelons,
watermelons, pumpkins, squash, cucumbers or other cucurbits have been planted.
Squash and pumpkins grow best on fertile, well-drained soil supplied with
organic matter. The ideal pH for pumpkin and squash growth is between 6.0 to 7.5, but they will
grow on soils with a pH of up to 8.0. Consult a soil test for fertilizer and liming recommendations.
Winter squash and pumpkin root to a depth of 48 inches or more. Maintain soil
moisture above 60% of the soil water holding capacity. It is important to regulate irrigations properly
to avoid excessive moisture or water stress.
For Kabocha squash, use well drained soils to minimize occurrence of
ground spot (light green or yellow spot). Clay soils should be avoided as should any locations that may
increase the probability of fruit surface scarring.
The minimum soil temperature required for germination of these crops is
60 F, with the optimum range between 70 and 95 F.
WINDBREAKS
Use windbreaks as necessary especially in eastern Oregon. Grain
windbreaks have been found
effective when grain rows are used for each crop row. Winter wheat varieties,
rye, or oats can be
used. Spring barley may be used for February plantings. Seed grain thickly,
2-3 seeds per inch. This requires about 10 lb of barley, 9 lb of wheat, or 8 lb of rye to seed
grain rows 12 feet apart.
Crop rows and windbreaks should be cultivated after they are well
established. Windbreaks may
be cut off or rotary tilled around June 25 before vines develop long runners
that may be damaged by tractor tires.
SEEDING
Pumpkins and squash are usually direct-seeded when all danger of frost
has passed. Transplants may also be used.
Final spacings depend on vine size and intended use. When growing
pumpkins or winter squash
for processing, narrow spacings are used. Use spacings of 3 to 4 feet between
rows and 1.5 to 2.5 feet between plants within the row.
Plantings intended for fresh market are usually planted at wider
spacings:
Vine Type Between Rows Within Rows
Bush or short vine varieties: 3 to 5' 2 to 3'
Small-fruited large vines: 6 to 8 3 to 4
Large-fruited large vines: 6 to 8 4 to 5
A common spacing of 3' x 5' would produce 2,900 plants/acre and up to 4,000 10 to 15-lb pumpkins,
for a yield of about 20-30 tons/acre.
While wide spacings (8 x 3 feet) are generally recommended for Kabocha
types for optimum skin
color and reduced disease incidence, yield at this wide spacing would be low
(about 5-6 tons per
acre). A spacing of 6 feet between rows and 1 to 1 1/2 feet between plants in
the row has been
used successfully in New Zealand, and to a limited extent in Oregon, and
should be tried. This should result in yields of approximately 8-10 tons per acre.
For confectionery seed production, spacings of 3 feet by 3 feet are
commonly used. At these populations ground cover is dense and flowers
are quickly hidden under the canopy. For good set, high bee
populations (2-3 hives/acre) and prompt hive placement (soon after
the first female flowers open) are important for good pollination and
seed set.
FERTILIZER
Good management practices are essential if optimum fertilizer responses
are to be realized. These practices include use of recommended varieties, selection of adapted soils,
weed control, disease and insect control, good seed bed preparation, proper seeding methods, and
timely harvest.
Because of the influence of soil type, climatic conditions, and other
cultural practices, crop response from fertilizer may not always be accurately predicted. Soil test
results, field experience, and knowledge of specific crop requirements help determine the nutrients
needed and the rate of application.
The fertilizer program should insure adequate levels of all nutrients.
Optimum fertilization is essential for top quality, yields, and returns.
Recommended soil sampling procedures should be followed in order to
estimate fertilizer needs. The OSU Extension Service agent in your county can provide you with soil
sampling instructions and soil sample bags and information sheets.
Recommendations are based on a row spacing of 60 inches. With decreased
row spacings fertilizer rates should be increased.
Western Oregon soils:
Adjust pH to 6.0 or above.
Nitrogen (N)
Rates of 80 to 150 lb N/A are suggested with the lower rates of N being
applied when legumes were grown the preceding year or a green manure crop is incorporated into the
soil prior to planting. Apply one-half the nitrogen at or just prior to planting and the
rest when vines begin to "run".
If the application of N plus potash (K2O) exceeds 50 lb/A, there is
danger of seedling injury from the concentration of salt when fertilizer is banded at planting time.
There is less danger if the band application is split into two bands.
The danger is aggravated as the band comes closer to the seed. The danger is greater with sandy than with
finer textured soil. Immediate irrigation at the first sign of burn should reduce further injury.
There is more possibility of damage to seedlings on acid soils where the pH is below 5.5.
Phosphorus (P)
Phosphorus fertilizer should be banded at planting for vigorous early
seedling growth. Bands should be located 2" to the side and 2" below the seed.
If the soil test* Apply this amount of
for P reads (ppm): phosphate (P2O5) (lb/A):
0 to 15 120-150
l5 to 60 90-120
over 60 60- 90
*Assumes extraction procedures similar to those used by the OSU Central
Analytical Laboratory. Specific information on soil test procedures is
available from the Dept. of Crop and Soil Science.
Potassium (K)
Potassium should be applied before planting or banded at planting time.
Amounts above 40 lb K2O/A should be broadcast and worked into the seedbed.
See statements on fertilizer banding under "Nitrogen".
If the soil test* Apply this amount of
for K reads (ppm): potash K2O (lb/A):
0 to 75 100-150
75 to 150 60-100
150 to 200 40- 60
over 200 None
*Assumes extraction procedures similar to those used by the OSU Central
Analytical Laboratory. Specific information on soil test procedures is
available from the Dept. of Crop and Soil Science.
Sulfur (S)
Include 20-30 lb S/A in the annual fertilizer program for vine crops.
Use the higher rate on sandy soils. S is sometimes contained in fertilizers used to supply other nutrients
such as N, P, and K but may not be present in sufficient quantity.
Plants absorb S in the form of sulfate. Fertilizer materials supply
sulfur in the form of sulfate and elemental S. Elemental S must convert to sulfate in the soil before the S
becomes avail able to plants. The conversion of elemental S to sulfate is usually rapid for fine
ground (less than 40 mesh) material in warm moist soil.
Sulfur in the sulfate form can be applied at planting time. Some S
fertilizer materials such as elemental S and ammonium sulfate have an acidifying effect on soil.
Magnesium (Mg)
When the soil test value is below 1.5 meq Mg/100g of soil or when
calcium (Ca) is ten times more than the Mg, apply 10-15 lb Mg/A banded at planting. If Mg deficiency
symptoms appear, spray with 10 lb Epsom salts in 100 gal water/A.
Magnesium can also be supplied in dolomite, which is a liming material
and will reduce soil acidity. Dolomite should be incorporated into the seedbed at the rate of 1-1 T/A.
Boron (B)
In general, boron deficiencies are uncommon. If the soil test value for
B is less than 1 ppm, an application of 3 lb B/A is suggested. Boron should be applied uniformly to
the field as a spray or broadcast. Never band B fertilizer.
Zinc (Zn)
Zinc deficiencies are uncommon in Willamette Valley soils. When the
soil test is below 1 ppm Zn, a response to Zn is expected and 4 lb Zn/A should be included in the
fertilizer band.
Lime
Experimental work has shown that vine crops will produce good yields
over a fairly wide range of soil acidity. Lime applications are suggested when the soil pH is 5.6 or
below, or when calcium (Ca) levels are below 5 meq Ca/100g of soil.
The rate of lime application can be estimated from the following SMP
buffer table:
If the SMP buffer* Apply this amount of
test for lime reads: lime (T/A):
Below 5.2 4-5
5.2 - 5.6 3-4
5.6 - 5.9 2-3
5.9 - 6.2 1-2
*Assumes extraction procedures similar to those used by the OSU Central
Analytical Laboratory. Specific information on soil test procedures is
available from the Dept. of Crop and Soil Science.
The liming rate is based on 100-score lime.
Lime should be mixed into the soil at least several weeks before
planting. A lime application is effective over several years.
Some soils may have a fairly high SMP buffer value (over 6.5) and a
low pH (below 5.5). This condition can be caused by the application of acidifying fertilizer. In
this case the low pH value is temporary and the pH of the soil will increase as the fertilizer
completes its reaction with the soil. This temporary "active" acidity from fertilizer is encountered
following recent applications of most N fertilizer materials. Acidifying fertilizers also have
a "long term" acidifying effect on soil that is cumulative and leads to lower SMP buffer readings.
Sandy soils to which fertilizers have not been recently applied sometimes record low pH and high SMP buffer values. In such cases, a light application of 1-2 T/A of lime
should suffice to neutralize soil acidity.
For acid soils low in Mg (less than 0.8 meq Mg/100g of soil), 1 T/A of
dolomite lime can be used as a Mg source. Dolomite and ground lime stone have about the same ability to
neutralize soil acidity.
The possibility of seedling injury from the band application of
fertilizer is less when the soil pH is 5.6 or above. Some Willamette Valley experiments have shown decreased uptake
of phosphorus from band applications of P when the pH approaches 5.5.
Lime applications should be broadcast, preferably in the fall, and
incorporated into the seedbed. Do not plow lime down leaving the surface soil unlimed.
Fertilizer Guide #3, "Liming Materials for Oregon", which is available
from your local OSU Extension Office, provides additional information on lime.
These fertilizer recommendations are based on research conducted by OSU
Horticulture and Crop and Soil Science faculty, and are quoted from OSU Fertilizer Guide FG 68.
Eastern Oregon soils:
Nitrogen: 40-60 (N) lb/acre (banded at time of planting).
Just before the vines begin to spread, side-dress with another 25-50
lb N/acre. Where mulching and trickle irrigation is used, nitrogen can be fed through the
trickle irrigation at 15-25 lb/acre when the vines begin to spread. To prevent clogging or plugging from
occurring use soluble forms of nitrogen (Urea or Ammonium nitrate) and chlorinate the system
once a month with a l0-50 ppm chlorine solution. Chlorinate more frequently if the flow
rate decreases.
Phosphate: 115-125 (P2O5) lb/acre (banded at time of planting).
Potassium: 50-100 lb/acre as indicated by soil test. If any K is
needed, broadcast and disk-in prior to planting.
POLLINATION
It is recommended that one honey bee hive should be introduced for every
1 to 2 acres during the blooming period since naturally occurring bee populations may not be adequate,
or their activity may not coincide properly with the bloom period.
Pumpkins and winter squash bear separate male and female flowers
on the same plant (monoecious). Bees transfer pollen from male to female flowers making fruit
set possible. Information from Michigan and New York indicates that pumpkin flowers need
8-10 visits per female flower for adequate pollination and that each female flower is only
receptive for about 24 hours. Research at OSU supports this finding. Multiple pollinator visits are
needed, with the number dependent on crop, bee species, time of day, temperature, and other factors.
Although a pumpkin plant will continue to form female flowers over a
period of several weeks, delayed pollination may also results in an undesired delayed maturity.
Pumpkins produce from 25-35 female flowers per plant and many male flowers. In large-fruited
pumpkins about 5% of the flowers need to be set to produce an economical yield. In
small-fruited varieties, as many as 40% of the female flowers may need to be set for an economical yield. For more information on beehive quality and pollination, see the
OSU Publication PNW-245 Evaluating Honey Bee Colonies for Pollination, A
Guide for Growers and Beekeepers.
STIGMA DEATH
In addition to pollination, development of female flowers may be affected by temperature. Recent experience
in the Middle Atlantic states and in New England indicates that high night temperatures (above 65 F) are associated
with failure of female flowers to open and develop properly. The ovaries turn yellow and then shrivel and the stigma
of the unopened flower exhibits black streaks into the ovary. 'Howden' is particularly susceptible.
IRRIGATION
Pumpkins and winter squash require uniform irrigation for optimum growth
and yield. Reduce irrigations as fruit reach harvest stage. A total of 12-15 inches of water
may be needed in western Oregon and 20-25 inches in eastern Oregon, depending on seasonal variation,
area and variety. Approximate summer irrigation needs for the Hermiston area have been found to
be: 3.5 inches in May, 5.0 in June, 7.5 in July, and 7.0 in August.
See also the OSU Irrigation Guide for this crop.
HARVESTING, HANDLING, AND STORAGE
In the Willamette Valley, Golden Delicious squash are harvested for
processing from September 15 to October 31 from mid-May plantings. The prime harvest period is from
September 15 to October 15.
Processing squash: Mechanical aids (tractor mounted V-shaped
sweeps) are used to windrow Golden Delicious squash for mechanized pick up and loading into trucks for
fruit intended for processing. A mechanical butternut squash harvester was developed by Gerald
Malburg, a Michigan grower, in 1993. It is reported capable of harvesting 20-25 tons per
hour.
Fresh market squash: All fresh market pumpkin and squash is
harvested by hand. Pumpkins can be harvested anytime after their rinds are hard and their skins have
turned orange, and the ground side has developed a yellow color. Harvest before they are injured by
freezing or too much rain. Extended exposure (1-2 weeks) of pumpkins and winter squash to
temperatures below 50 F. can result in chilling injury, and excessive decay in storage.
Cut pumpkins from the vines, leave 3-4 inches of stem attached to the fruit since pumpkins without
stems do not store well. Do not handle pumpkins by their stem since they may easily break
off.
Good yields of small varieties range from 5 to 7 tons or 2000 to 4000
fruit per acre. Large pumpkins may yield 10 to 20 tons or 1,000 to 2,000 fruit per acre.
Yields of specific varieties of pumpkins and winter squash obtained from
multiple year data from the Dixon Springs Agricultural Research Center in Illinois:
Average yield Fruit Size
Variety Number/acre tons/A (lb)
Howden Field 2,400 22.9 19
Connecticut Field 1,300 11.7 18
Thomas Halloween 1,250 8.8 14
Jackpot 2,250 14.6 13
Trick or Treat 2,300 13.6 12
Spirit 3,600 19.8 11
Pankow's Field 2,200 12.1 11
Autumn Gold 5,150 23.2 9
Little Boo (white) 1,600 3.2 4
Spookie 5,800 10.2 4
Baby Pam 2,550 2.6 2
Mini Jack 5,200 3.9 1
Information from Michigan indicates that in general, good to
excellent yields of Halloween pumpkins are generally 15 to 20 tons per
acre.
Yield of seed from hulless or naked-seeded pumpkins should range from
800 to 1500 pounds per acre.
Winter squash should be harvested only when fully mature. Indications
of maturity are a hard rind and a solid exterior color. The acorn types are harvested when a
yellow-orange color has developed on the fruit where it is in contact with the soil. To harvest,
remove the stem completely from the fruit, and allow the stem scar to dry before storing.
Yields of Hubbard, Marrow and other large squash, pie pumpkins, acorn,
butternut and summer squashes would be 15-20 tons/A; gourds 4-5 tons/A; and buttercup squash are
10-15 tons/A.
Due to the wider spacings needed for Kabocha squash, gross
yields of this type of buttercup squash would more likely be 5 to 10
tons/A of well colored fruit (see other comments about yield in the
section on SEEDING above). Data from the OSU experiment station in
Medford in 1988 obtained the following marketable yields of three types
of "Kabocha":
Variety tons/acre lb per fruit Culls tons/acre
Sweet Mama 16.0 4.42 9.1
Honey Delight 19.3 4.36 3.6
Kuryjiman 15.3 3.27 3.8
Kabocha squash is harvested by cutting the stem and leaving 1 to 2 inches.
Ideal fruit size is 3 to 6 lb.
Research (with muskmelons) suggests that pumpkins and winter squash may
benefit from being dipped in 135-140 F water for 3 minutes, and dried quickly before storage.
Warm, wet fruit are subject to invasion by micro-organisms, therefore drying and cooling to the
storage temperature should be done immediately following this treatment. This hot water treatment
surface sterilizes the fruit. No benefit has been found from chlorination of the hot water, but
gently wiping the surface clean with 1 part household bleach in 10 parts of water may be
helpful.
STORAGE (Quoted or modified from USDA Ag. Handbook 66 and other sources)
Store at 50 to 55 F and 50 to 70 % relative humidity. Pumpkins and
winter squashes are placed on racks, in bulk bins, or baskets and are held in ventilated or common
storage in production areas. Most cultivars of pumpkins do not keep as well as hard-shelled winter
squashes; both types of vegetables are subject to chilling injury at low temperatures. Such
cultivars of pumpkins as Connecticut Field and Cushaw cannot be expected to hold in good condition more
than 2 to 3 months at 50 to 55 F.
All winter squashes should be well matured, carefully handled, and free
from injury or decay when stored. They should be kept dry, and storage rooms should have good air
circulation. Relative humidities of 50 to 70 % (60 % may be optimum) are recommended for pumpkins
and winter squashes, which are lower than those recommended for most vegetables. Higher
humidities promote decay and lower humidities cause excess weight loss and texture
deterioration.
Acorn-type squashes, such as Table Queen, should keep 5 to 8 weeks at 50
F. At higher temperatures 60 to 70 F, Table Queen will lose greenness, become undesirably
yellow, and acquire a stringiness of the flesh in 5 weeks. At 32 to 40 F yellowing does
not occur but chilling does. Alternaria rot develops on chilled squashes after their removal
from storage.
The popular Butternut squash should keep at least 2 to 3 months at 50 F.
Often it is stored for longer periods, but spoilage and shrinkage increase. Weight loss should be
kept below 15% to minimize development of hollow neck, and a relative humidity of 50% is
recommended.
Kabocha, Turban and Buttercup squashes should keep at least 3 months
under good conditions. Since kabocha squash intended for export must meet stringent skin color and
other quality standards, kabocha intended for export should be handled as per the export
company specifications.
Hubbard squash, if in good condition initially, can be successfully
stored 6 months at 50 to 55 F with 70% relative humidity. A 15% loss in weight from shrinkage for 6 months
storage would be average.
A 10 to 20 day curing period at 75 to 80 F before storage is sometimes
recommended for pumpkins and winter squashes. However, experiments in New York showed that a
preliminary curing for 3 weeks at 80 F before storage to heal mechanical injuries and to
ripen immature specimens was unnecessary. Curing Butternut, Hubbard, and Quality squashes
was of no value but not harmful, whereas curing Table Queen was detrimental to skin color,
texture, and taste. Cured Table Queen also decayed more rapidly than uncured fruit.
Less rot will develop in the Hubbard squash if stems are completely
removed before storage.
Hubbard squash and other dark-green-skinned squashes should not be stored near
apples, as the
ethylene from apples may cause the skin to turn orange-yellow. Black rot, dry
rot, and bacterial
soft rot are the principal causes of spoilage of winter squashes in
storage.
PACKAGING
Winter Squash - hard types: 42-lb (l-l/9 bushel) crates; 800 to 900-lb
bulk bin cartons,
collapsible and reusable; 900 to 2000-lb various bulk bins.
Pumpkins: commonly packaged in various size crates and weights or
shipped in bulk truck loads.
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