2- Characteristics of the Species Cucurbita argyrosperma - Cushaw Pumpkin
2.1-BotanicalDescription + Plant Cucurbita argyrosperma isa creeping or climbing monoecious plant, ranging from villous to pubescent and which may be hirsute, with short, rigid and rather enlarged and sharp trichomes. It has fibrous roots and slightly angular stems. Plant is monoecious annual or short-lived perennial scandent herbs. Plant is with tendrils branched. The plant grows about 1 foot high and spreads 10-15 feet. It likes well drained soil and has both male and female flowers. Fruits can weigh up to 20 pounds. It is often found in close proximity to Cucurbita moschata. Stem is long-running or short and bushy, more or less scabrous, soft to hard, round to angular, often rooting at the nodes. +Leaves Leaves are simple, alternate, long petiolate; leaf-blade is broadly cordate to triangular in outline, shallowly to deeply lobed, often with whitish blotches, more or less rigid and scabrous. Its ovate-cordate leaves have petioles of up to 30 cm and measure 10 to 30 x 15 to 40 cm. They have white spots, number three to live and are lobulate with triangular or elliptical lobules. The margins are denticulate to serrate-denticulate. + Flowers There are two to four ramified tendrils and pentamerous, solitary, axillary flowers. The male flowers are on pedicels of 10 to 20 cm and have a campanulate calyx of 5 to 20 x 8 to 25 mm. Their sepals are linear-lanceolate or (rarely) foliaceous and are 10 to 35 mm long. They have a tubular-campanulate corolla that is yellow to orange, 6 to 12 cm long, with five lobules for up to one-third of its total length and they have three stamens. The female flowers grow on sturdy peduncles of 2 to 3.5 cm; have a globose, ovoid-elliptical, botuliforrn or piriform, multilocular ovary, a small calyx and a corolla that is somewhat bigger than that of the male flowers. They have three stigmas. The flowers are orange or yellow and bloom in July or August. + Fruits The fruit is short or long and piriform, straight or curved in the thinnest part and 11 to 50 cm long. It has a hard rind which is smooth to slightly ribbed, and is white with longitudinal green reticulate stripes or completely white. The flesh is white, yellow or orange. Fruit is a pepo; fruit stalk is soft to hard, round to angular, thickened with soft to hard cork, enlarged or not at point of attachment of the fruit. Fruits (typically 10-20 pounds each) on hard corky stems come in a variety of sizes often with elongated thick necks and with soft green or white or combination of green/white skin. Fruits include silver seed (flesh unpalatable - grown primarily for edible seeds rich in oils) and callicarpa (cushaw-type). The fruit is up to 20cm in diameter. + Seeds Seeds are numerous, flattened, usually white or tawny, sometimes dark-coloured. The seeds elliptical and slightly inflated, measuring 15 to 30 x 8 to 16 mm, with a white, smooth and even testa. The seeds yield an edible oil.
2.3- Biological characteristics + Ecology and phytogeography - Climates The plant's adaptation to warm climates, and a resistance tosquash borers, make it very competitive in the agricultural industry. A frost-tender annual plant, the Cushaw pumpkin has long been cultivated for its edible fruit especially in warmer temperate and tropical areas. It requires a rich, well-drained moisture retentive soil and a very warm, sunny and sheltered position. Plants are tolerant of high temperatures but sensitive to cool conditions, they favour moderate rainfall but the roots are sensitive to water-logging. It can grow in semi-shade (light woodland) or no shade. The species does not tolerate very low temperatures, which limits its cultivation to the altitudes mentioned. Each cultivated variety has a fairly defined distribution model, although there are some areas where two varieties can be found cultivated simultaneously. In Mexico, the Cucurbita subsp.argyrosperma var. argyrosperma is grown on the slope of the gulf (Tamaulipas, San Luis Potosi, Puebla, Veracruz, Tabasco, Chiapas and Yucatan). In Central America it has been recorded in Belize, Guatemala, Honduras, El Salvador, Nicaragua, Costa Rica and Panama. The Cucurbita subsp.argyrosperma var. callicarpa is found mainly on the Pacific slope, from the southeastern United States to central Mexico (Sonora, Sinaloa, Chihuahua, Zacatecas, Guanajuato, Nayarit and Jalisco). The Cucurbita subsp.argyrosperma var. stenospermais endemic to Mexico and is grown in the central and southeastern states (Guerrero, Morelos, Michoacan and Oaxaca) as well as in some areas of the gulf slope (Veracruz and Yucatan). - Soil It is suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. It is best grown in fertile, organically rich, medium moisture, well-drained loams in full sun. It also prefers moist soil. It is suitable with pH: acid, neutral and basic (alkaline) soils. - Altitudes The three cultivated varieties of Cucurbita argyrosperma are found in a relatively wide range of altitudes (0 to 1 800 m), generally in areas with a hot, fairly dry climate or a well-defined rainy season.
+ Genetic diversity - Limits of genetic stock Knowledge of the genetic relations of Cucurbita argyrosperma Huber and the consequent inclusion and definition of wild and cultivated taxa within its taxonomic limits have considerably widened the species "genetic stock”. This includes: the local races of the cultivated varieties in the southeastern United States, Mexico and Central America; the two wild taxa of the complex (Cucurbita subsp.argyrosperma var.palmieriand Cucurbita subsp. sororia); and, in the United States, Green Striped Cushaw, White Cushaw, Magdalena Striped, Papago, Silver Seed Gourd, Japanese Pie, Hopi, Taos, Parral Cushaw and Veracruz Pepita. Hybridization experiments of the taxa belonging to Cucurbitaargyrosperma with other wild and cultivated taxa of the genus and some field observations have revealed that, with the cultivated species, Cucurbitamoschata has the highest degree of compatibility. A second level of compatibility consists of the wild and cultivated taxa of Cucurbita pepo, some cultivars of Cucurbita maxima and the wild perennial species ofCucurbita foetidissimaH.B.K. A third group is formed by CucurbitalundellianaL. Bailey, and CucurbitamartineziiL. Bailey, with which crossings only produced fruit without viable seeds. The fourth and last group includes the perennial species CucurbitapedatifoliaL. Bailey,Cucurbita digitataA. Gray, in the broad sense and Cucurbita radicans Naudin, with which only a few fruits were ableto be obtained but generallywithout viable seeds. The wild species that have shown some degree of compatibility with the taxa of the complex Cucurbita argyrosperma possess genes resistant to some viral diseases that have a high incidence in the cultivated species. However, because of two actors relating to interspecific crossings, some obstacles will have to be overcome before a successful plant improvement programme including all the taxa is carried out: 1- Hybrids with viable seeds were not always produced; 2- When some success was achieved, the plant receiving the pollen was always from the complex Cucurbita argyrosperma and, in the case of the species of the last two groups, it always involved Cucurbita subsp.argyrosperma var.palmierior Cucurbita subsp. sororia. - Germplasm collections Germplasm collections are not so scarce for the cultivated taxa but they are in very short supply in the case of the wild ones. Most of the accessions come from Mexico and are deposited in the ClFAP's gene bank in Mexico and in the USDA's in the United States.
+ Propagation Seed - sow early to mid spring in a greenhouse in a rich soil. Germination should take place within 2 weeks. Sow 2 or 3 seeds per pot and thin out to the best plant. Grow them on fast and plant out after the last expected frosts, giving them cloche or frame protection for at least their first few weeks if you are trying them outdoors.
3- The Uses of Species Cucurbita argyrosperma - Cushaw Pumpkin
3.1- Food uses Throughout its distribution area, the flowers, young stems, young fruit and ripe fruit of Cucurbita argyrosperma are eaten as vegetables. The ripe fruit is occasionally used to prepare sweets although it is used most frequently as feed for livestock and poultry. The flesh can be dried, ground into a powder and mixed with cereals for making bread, cakes etc. It is used especially in the southern states of the U.S. for use in pies, preferred over other pumpkins by some cooks. The seed is rich in oil and has a pleasant nutty flavour. It is used as a vegetable in pies etc, it can be stored for up to 6 months. The seeds yield an edible oil. The seeds are eaten whole, roasted, toasted or ground and are the main ingredient of sauces used to prepare various stews (for example,pipián - meat cooked in thick chili sauce,mole verde -a stew prepared with chili and green tomatoes). The seeds are the most important product, chiefly because of their oil (39 percent) and protein content (44 percent), and their consumption in urban areas of Mexico and other countries of Central America is fairly common. In some regions of Mexico, the seeds and also the unripe fruit of wild taxa are used as food. The latter are eaten after being washed and boiled several times to rid them of the bitter taste deriving from the cucurbitins present in the flesh and placentae, while the seeds are simply washed, seasoned with salt and roasted or toasted.
3.2- Medicinal Uses Cucurbita argyrospermaalso has medicinal properties. A liquid emulsion of its seed can act as avermifuge, and the subsequent use of alaxativecan effect an expulsion of parasitic worms. The seeds are used as vermifuge. The complete seed, together with the husk, is used. This is ground into a fine flour, then made into an emulsion with water and eaten. It is then necessary to take a purgative afterwards in order to expel the tapeworms or other parasites from the body. As a remedy for internal parasites, the seeds are less potent than the root of Dryopteris felix-mas, but they are safer for pregnant women, debilitated patients and children. Another medicinal use of Cucurbita argyrosperma is that of the flesh, which can be used for burns, eczema, and promoting lactation in nursing women.
4- Growing Cushaw Pumpkins on the World
4.1- Subspecies and varieties Cucurbita argyrosperma isone of the cultivated species of the genus which has undergone the most profound study in recent years. There are two subspecies: 1- Cucurbita subsp. argyrosperma 2- Cucurbita subsp. sororia + Cucurbita subsp. argyrosperma,comprising four varieties: 1- Cucurbita subsp. argyrosperma var. argyrosperma 2- Cucurbita subsp. argyrosperma var. callicarpa 3- Cucurbita subsp. argyrosperma var. stenosperma and 4- Cucurbita subsp. argyrosperma var. palmieri Three of which include all the cultivated types, while the fourth corresponds to spontaneous populations of northeastern Mexico that are generally known as Cucurbita palmieri L. Bailey. + Cucurbita subsp. sororiawhich includes wild populations with a wide distribution from Mexico to Nicaragua, originally described under the name CucurbitasororiaL. Bailey. This subspecies has been designated as the wild ancestor of the group. According to the age of the archaeological remains discovered thus far, it has been suggest ed that domestication of Cucurbitaargyrospermamust have occurred in southern Mexico more than 7 000 years ago. The characteristics that were most transformed in the process of domestication of the Cucurbita subsp. argyrospermawere, as in other crops, mainly those connected with handling and preferred uses. For example, relatively uniform germination; a reduction in size and abundance of trichomes; an increase in the size of parts and organs used, such as fruits and seeds; and a reduction in the bitter taste of the flesh. It is considered that Cucurbita subsp. argyrosperma var. argyrospermais the least specialized or most primitive of the group and that Cucurbita subsp. argyrosperma var. callicarpa,on the other hand, is the most recent or specialized. The different degrees of variation in the nutritionally important parts of the three cultivated varieties of the complex Cucurbita argyrosperma suggest a strong association with human interests. The relatively large seed size of the Cucurbita subsp. argyrosperma var. var. argyrosperma indicates that it was mainly selected to obtain seeds, while the great diversity of shapes, colours and size of the fruits and seeds of Cucurbita subsp. argyrosperma var. stenospermaand Cucurbita subsp. argyrosperma var. callicarpaindicate that selection had a double aim: to obtain flesh as well as seeds. Unlike with the rest of the cultivated species of Cucurbita,data on the distribution of cultivated Cucurbita argyrosperma varieties outside America are very scarce and there is no certainty that this species was cultivated at any time in the Old World or even outside its general area of domestication. In South America, it is grown in Peru and Argentina, although it appears to involve very recent introductions of certain cultivars which can be classified within the Cucurbita subsp. argyrosperma var. callicarpa. In the United States, some cultivars of Cucurbita subsp. argyrosperma var. callicarpaare cultivated on a very low scale for nutritional purposes, and one cultivar of var. argyrosperma,Silver Seed Gourd, is occasionally grown as a horticultural curiosity. The reasons for the sparse world distribution of this species are not known; although the situation is not surprising, given the low quality of the fruit's flesh compared with that of Cucurbitamoschataor Cucurbitapepoand the size of the seeds of all the cultivated varieties that may have been attractive to the first Europeans who learned of them.
4.2- Cultivation practices The cultivated varieties of Cucurbita argyrosperma are worked in the traditional heavy rain agricultural systems and are sown at the start of the rainy period (May-June). Development of these varieties lasts five to seven months; the young fruit for vegetables is harvested approximately three months after being sown, while the ripe fruit for seed is harvested between October and December. In the Mixe region of the state of Oaxaca, Cucurbita subsp.argyrosperma var.stenosperma isalso grown in the dry season on so-called humid ground. This practice is also recorded in some parts of the state of Sonora in northeastern Mexico, where some cultivars of Cucurbita subsp.argyrosperma var. callicarpa can be grown in the dry season, but always with the help of irrigation to ensure production throughout the year. The only form of propagation is the sowing of seed which is done along with some of the traditional crops of this agricultural model (maize, beans and other species of Cucurbita). In some regions of Yucatan, Quintana Roo and Oaxaca the seeds of Cucurbita argyrosperma are often the first to be planted in the maize fields. Sowing begins shortly before the start of the rain and before the other associated crops are sown. In some localities of Yucatán. sowing is done very quickly the day after the traditional burning of the stubble of the previous crop and long before the first rain and the sowing of other associated crops. The aim is to prevent the development of weeds which would affect production of the other species cultivated in the maize field, utilizing the rapidity of growth and cover attained by this species. Practices of this type show that the seeds of Cucurbita argyrosperma are completely suited to these regions and germinate even in conditions of low humidity. Unlike other cultivated species of the genus, it is less frequent for varieties of the Cucurbitaargyrosperma complex to be found in vegetable gardens or plots or in small agricultural holdings or to be associated with other species.