Dudaim melon [Cucumis
melo L. var. dudaim (L.) Naudin][CUMMD][CDFA list: A] Photographs
Map of Distribution
Paddy melon [Cucumis
myriocarpus Naudin][CUMMD][CDFA list A] (see Similar Species) Photographs
Map of Distribution
SYNONYMS:smell melon; pomegranate melon; Queen Annes pocket melon;
C. odoratissimus Moench.
DESCRIPTION:A weedy summer annual form
of muskmelon, with trailing prostrate stems to 10 m long or more and often
forming large mats. Fruits are more or less edible, but plants are most often
grown as ornamentals or for the fragrance of the fruits. Plants require much
moisture, grow rapidly, and are often highly productive. All varieties of
muskmelon, including the commercial cultivars of cantaloupes [C. m.
L. var. reticulatus Naud.], readily hybridize with one another, making
the presence of dudaim melon in commercial cantaloupe fields highly undesirable.
Introduced from tropical Africa.
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SEEDLINGS:Resemble those of commercial muskmelons and cantaloupes. Require
much water to reach maturity. High seedling mortality is common.
PLANT:Stems prostrate, viny, herbaceous,
slender, angled in cross-section, several-branched near the base, and typically
rough to touch with short stiff hairs. Leaves alternate, more or less
palmate, angled or shallowly 3- to 7-lobed, typically 7-8 cm long,
5 cm wide, and covered with very short stiff hairs (scabrous). Tendrils
unbranched and 1 per node from the base of the leaf petioles (stipular
and UNDERGROUND STRUCTURES:Taprooted, with
extensive, shallow lateral roots that maximize absorptive area. Adventitious
roots occasionally develop at some leaf nodes.
FLOWERS:March-November. Flowers axillary, monoecious, with 1
or more male (staminate) flowers per node and single female (pistillate) flowers
at different nodes. Corollas yellow, 2-3 cm in diameter, and deeply 5-lobed,
with the petals fused at the bases to form a shallow cup-like tube. Male flowers
have 3 separate stamens. Female flowers have an inferior ovary.
and SEEDS:Fruits are produced from March
until the first hard frost. Pepos or melons oblong to round and generally
3-6 cm wide. Surfaces are net-veined or covered with minute stiff hairs
and lack prickles. Immature fruits are green, but become mottled
or striped with yellow or orange, or are solid yellow or orange
at maturity. Each fruit typically contains about 270 seeds. Seeds are ~ 5
mm long, covered with a sticky gelatinous coating, and resemble those of cantaloupe
in shape and color.
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CHARACTERISTICS:Dried fruits can remain
intact for an extended period, with one estimate to 20 years under ideal conditions.
HABITAT:Agricultural fields, especially those in or with past asparagus
production, roadsides, and disturbed sites. Often grows near ditches or where
water is plentiful.
DISTRIBUTION:Uncommon. Southeastern Sonoran Desert (c & e Imperial Co.).
To 200 m (660 ft).
Considered eradicated in California
at this time.
PROPAGATION/PHENOLOGY:Germinates nearly year round, except when temperatures are
freezing. Germination rates of newly matured seed are high (often > 95%).
Immature fruits can contain viable seed. Plants grow rapidly in the warmer
months and can produce hundreds of fruits in a short period (42 days). Dry
fruits become hard and can remain intact in the soil for extended periods.
Fruits float at all stages and can disperse with water. Animals eat
fruits at all stages, and excreted seeds appear to remain highly viable. Seeds
from broken fruits can adhere to animals, shoes, clothing, tools, and machinery
by the sticky coating, which dries like glue.
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and destroying or composting fruits can prevent dispersal to new sites.
SPECIES:Unlike commercial cantaloupe, immature
fruits of dudaim melon are covered with shorter, stiffer hairs,
and fruits become fragrant at 3-6 cm width and mottled or solid yellow/orange
with maturity. Paddy melon or bitter apple [Cucumis myriocarpus
Naudin] is also a summer annual, but differs from dudaim melon
by having deeply lobed leaves and round fruits 2-3 cm wide covered
with weak prickles. Fruits, especially seeds, contain cucurbitacins, compounds
that can be toxic to livestock or humans when consumed. Paddy melon
does not hybridize with commercial melons or dudaim melon and is susceptible
to several viruses that affect tomatoes and potatoes. It occurs in fields
and disturbed sites in the central and southern San Joaquin Valley and southwestern
South Coast Ranges (Santa Barbara Co.). To 300 m (1000 ft). Introduced from
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Prevention: Dudaim melon
is a weedy annual form of the agriculturally important musk melon (Cucumis
melo). It can be utilized for food, but is commercially classified as non-edible.
Dudaim melon was thought to be introduced to the Imperial Valley in 1953.
It has not been reported beyond the Imperial Valley in California, and extensive
eradication efforts have been implemented since 1967. Dudaim melon forms large,
dense mats of vines that compete with agricultural crops such as asparagus,
cucumber, and musk melon. The greatest threat is its ability to readily hybridize
with commercially important varieties of musk melon. The resulting hybrids
produce small, bitter melons of poor quality. One dudaim melon plant may produce
several hundred melons, each of which may contain over 200 seeds. Germination
rates for fresh seed are >95%. Upon reaching maturity, the melons become
extremely hard, and seed may be viable for 20 years. Seed are also covered
with a mucilaginous coating that sticks to equipment, animals, shoes, and
tools. Once dried, the mucilaginous coating is very difficult to remove, even
with a steam cleaner. Dudaim melon is a CDFA class A noxious weed.
Dudaim melon also grows along waterways and irrigation canals. The pepos (melons)
will float at any stage and may be transported in water for long distances.
Infestations along waterways and irrigation ditches should be controlled to
prevent seed dispersal to new areas.
Prickly paddy melon is a vinelike, summer annual that is often found in fallowed
fields. Growth is rapid following spring rains and melon production is prolific.
It is a CDFA class B noxious weed.
Mechanical: Tillage can
be very effective for controlling both dudaim and prickly paddy melon. However,
dudaim plants may form adventitious roots from nodes along prostrate stems.
Therefore, any tillage should completely sever the roots from the shoots and
control will be improved if hot, dry conditions follow. Tillage should be
conducted before any melons are produced, because some seed are viable, even
in very immature pepos.
Biological: Since both dudaim
and prickly paddy melons are very closely related to musk melon, biological
control has not been pursued. Eradication should be the primary objective
when dealing with dudaim melon, and strategies that completely eliminate seed
production should be implemented.
Grazing may be effective for controlling these weedy melons. Dudaim melon
has been reported to infest pasturelands in the Mexicali Valley in Mexico.
Cattle have shown a preference for the pepos. However, the seed can remain
viable after excretion in the feces. Therefore, cattle should be removed from
infested areas before melons are produced, or should be quarantined prior
to movement to other areas.
Chemical: There is very
little information regarding chemical control of dudaim melon. Contact herbicides
such as paraquat are generally ineffective on large plants, unless thorough
coverage is attained. A tank mix of triclopyr (0.20 lb ae/A) and 2,4-D (1.6
lb ae/A) is effective for controlling prickly paddy melon. Glyphosate is generally
ineffective on prickly paddy melon and is not recommended. Herbicides should
be applied when plants are small. Control will likely decrease with increasing
Integrated management strategies:
Dudaim melon is very difficult to control in established stands of asparagus.
The optimal time for melon (seed) production occurs from June through September,
which coincides with the optimal time for fern growth of asparagus following
harvest. Fern growth is necessary for maximal carbohydrate storage for the
following year's crop. There are few control measures that can be implemented
after the ferns develop. Fields should be thoroughly surveyed before rotating
to asparagus or melons, where dudaim melon is most difficult to control.
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