Cucurbit Genetics Cooperative Report 23:105-? (article 35) 2000
Breeding, Production, and Utilization of Oil Pumpkin in Yugoslavia
Institute of Field and Vegetable Crops, 21000 Novi Sad, Yugoslavia; berenji@EUnet.yu
Abstract: The classification, breeding (history, methods and breeding goals), production (including the traditional practice of intercropping along with the present way of production in pure culture) and utilization (whole fruit or the flesh of the fruit for cattle feed and the seeds for snack, oil production or medicinal purposes) of oil pumpkin (Cucurbita pepo L.) in Yugoslavia are outlined in this paper. The breeding goals (general plant characteristics, seed coat type, seed characteristics, fruit characteristics, resistancy to diseases) as well as the pharmaceutical aspects (in relation to benign prostate hyperplasia) are elaborated.
oil pumpkin, breeding, naked-seeded, hulled, production, utilization, snack, oil, benign prostate hyperplasia
Classification: The most common cucurbits grown in Yugoslavia, in order of their decreasing economic importance, are: cucumber, watermelon, cantaloupe, Cucurbita species, mostly used as summer squash (C. pepo), or winter squash (C. maxima, C. moschata, C. ficifolia and C. mixta) and the gourd (L. siceraria) as a vegetable (7). The fruits of C. pepo, C. maxima and L. siceraria are popular decorations. The attention paid to chayote Sechium edule ( Jacq.) Sw. as a new vegetable is increasing, and Luffa sp. is becoming also popular. Oil pumpkin, belonging to C. pepo is mainly grown or seed. The utilization of the seed is determined mostly by its oil content (9). Recently demand has been shown for C. maxima seeds for the same purpose as C. pepo oil pumpkin.
Breeding: History of breeding. Landraces of oil pumpkin, without a specific name, maintained by farmers and characterized by hulled seeds, elliptic, dark green fruits with an orange spot on the surface of the fruit touching the soil prevailed in production until recently. The naked-seeded oil pumpkin was almost completely unknown, except for the occasional spontaneous mutations resulting mostly in half-hulled seeds, considered more as an attraction without a recognized economic importance. It was not until the early 1980's that naked-seeded cultivars entered the production, and hulled-seeded cultivars did even later.
The only active oil pumpkin breeding program in the country is located at the Institute of Field and Vegetable Crops in Novi Sad. As the result of more than two decades of research and development in oil pumpkin genetics and breeding (4), during which several successful collaborations have also been established (i.e. with DUDU Bt. Debrecen, Hungary), the naked-seeded oil pumpkin cv. 'Olinka' has been officially registered in Yugoslavia in 1992 and the hulled-seeded cv. 'Olivia' in 1997. consequently both cultivars were registered in Hungary (1995) and in Slovenia (1999) as well.
Breeding methods: Mass selection and individual selection (occasionally with overstored seed) based on local populations or populations obtained by crossing have ben applied (Fig. 1). The investigation of heterosis showed positive hybrid vigor for most of the economically important traits of the hull-less seeded oil pumpkin (1). Ethephon treatment as a possible tool for commercial hybrid seed production was also successfully tested (2).
Breeding goals: The most important current and future breeding goals are: (a) general plant characteristics (the semi-bush growth habit characteristic for the cv. 'Olinka' favored over vining stem typical to 'Olivia' shown on Fig. 2, growth energy, number of fruits per plant), (b) seed coat type (naked-seeded without any seed coat development at the seed margins as well as the typical hulled-seed type are equally involved as shown on fig. 3, but the potential of a half-hulled or partially-hulled type is also under consideration), (c) seed characteristics (dimensions, mass, color, ease of dehulling, taste, chemical composition i.e. oil content, irregular seed development, ease of separating the seed form the fruit called harvestability), (d) fruit characteristics (fruit dimensions, shape and weight, thickness and mass of flesh, fruit color, fresh as well as dry seed mass per fruit), (e) resistance to diseases (anthracnose and viruses) (3).
Detailed correlation analysis has been carried out between the more important fruit and seed characteristics from the breeder's point of view (to be presented at the VIIth EUCARPIA Meeting on cucurbit Genetics and Breeding "Cucurbitaceae 2000," Israel, March 19-23, 2000.
Intercropping. The oil pumpkin has been traditionally intercropped with corn (11). Pumpkins were harvested at the same time as corn, carefully transported to the barnyard a d occasionally fed to the cattle long into the winter. This could be called forage, rather than oil pumpkin. Later more and more attention was paid to the seeds which were removed, dried and collected for further use. Intercropping is still practiced in some parts of Yugoslavia. It is hard to estimate the total area of corn intercropped with oil pumpkin but it is certainly still above 10.000 ha. Intercropping of oil pumpkin in corn is again gaining some interest from the point of view of sustainable agriculture (10).
Pure culture. The contemporary practice of oil pumpkin growing is in pure culture (5, 8). This kind of production could be estimated to an annual 1.500-2.000 ha. The growers are mostly small farmers usually with 0,5-1 ha of pumpkin. The crop is mostly planted by machine,. Instead of herbicides (usually Trifurcating) mostly mechanical weed control is practiced. Neither chemical treatment against diseases (fusarium root rot, powdery mildew, anthracnose, viruses) or insect pests (aphids) is applied, nor is mineral fertilization widespread, which fulfills completely the requirements of organic production. Around 3/4 of the production is hand harvested separating seeds from the previously halved fruits, but home-made harvesters are also used. The prototype of a new construction keeping the flesh clean after the removal of the seed, is a prerequisite for the further utilization of the flesh, is being tested, At present practically all the flesh is discarded after the harvest. The removed seed is usually dried in the sun. The dried seed is rarely stored, mostly sold immediately to the seed traders, roasters or oil mills.
Lack of complete fertilization could be a problem, resulting in "empty" seeds of the hulled-seeded oil pumpkin. Enhancement of fertilization by placing bee hives near the pumpkin fields is recommended. Seed set and seed fill was considerably improved by Boron (i.e. Solubor DF (R)) treatment. The effect of the Ethephon (proposed for commercial hybrid seed production) on the shortening of the internode length as well as improvement of fruit set was also observed.
The favorable effect of planting corn rows at some 5-10 m distance from each other along the oil pumpkin field has been observed. The resulting microclimate obviously stimulates the pumpkin plants and prevents the outbreak of diseases. Rodents are attracted by the corn cobs, thus preventing damage to the pumpkin fruits.
Utilization:Cattle feed. The type of the plant called hulled-seeded oil pumpkin in this paper was traditionally used for cattle feed (6). Often the whole fruit was fed to the cattle, but sometimes only the flesh after removal of the seeds was used for feeding. To provide fresh fruits (sometimes cut into pieces and cooked in water right before feeding) for the cattle (mainly dairy cattle but also for swine and horses), the fully ripe fruits were stored in a frost-free place where they remained basically undamaged during the whole winter. Studies showed that pumpkin,mixed with corn stalk, could be a valuable raw material for silage production.
At present, the seeds are the main product with very few cases of fresh utilization.
Snack. The seed of oil pumpkin is traditionally used as a homemade snack, especially the hulled-seeded oil pumpkin. Not only the oil, but also the protein content of the seed is important in this respect, giving the roasted seed a special, pleasant taste. There is a growing number of small companies specializing in roasting and packing seed for snacks. Dehulling the roasted pumpkin seed (with the teeth) is a very common pastime while watching a football game, TV or a movie, as well as traveling on public transportation vehicles.
Pumpkin seed oil. Oil production is a relatively new use of pumpkin seed,s hull-less seed being preferred to hulled in this case. The oil is produced by and is a popular item offered by natural food stores mainly as a delicious and healthy salad oil.
Medicinal use. The pharmaceutical aspect of the oil pumpkin seed and seed oil is related to the benign prostate hyperplasic (BPH). BPH is not a life-threatening disorder, but can substantially reduce the quality o0f the patient's life. The therapy includes herbal prostate drugs, phytomedicines. Unlike in the USA< in Europe the use of prostate gland drugs derived from plants including the oil pumpkin is very widespread. Among the herbal medicines Cucurbitae peponis semen have the longest tradition in successful BPH treatment in Europe going back to the 18th century. The pharmaceutical effect of the pumpkin-seed oil is attributed to the delta-7-sterols, amino acids, and selenium (13). The results of a clinical study of the effect of the seed oil deriving from the naked-seeded oil pumpkin cv. 'Olinka" clearly showed its prostatotropic activity (lowered amount of residual urine and enhance micturation speed) in comparison to an untreated control group of patients with BPH (12).
- Berenji, J. 1988. Hibridna snaga kod uljane tikvegolice, Cucurbita pepo L. Uljarstvo 23(3-4):79-85.
- Berenji, J. 1988. Poznavanje tikava, Cucurbita sp. Zbornik referata "3. Poljedelski dnevi ABC Pomurka", Murska Sobota.
- Berenji, J. 1989. Ciljevi oplemenjivanja uljane tikve, Cucurbita pepo L. Zbornik radova Savetovanje proizvodjaca Biljnih ulja i masti Jugoslavije, Beogrd, p. 134-135.
- Berenji, J. 1992. Tikve. Bilten za Hmelj, sirak i lekovito bilje 23-24(64-65):86-89.
- Berenje, J.1994. Uljana tikva. In.: Tehnologija proizvodnje lekovitog, aromaticnog i zacinskog bilja. Institut za ratarstvo i povrtarstvo Novi Sad i Agroseme-Panonija Subotica.
Berenji, J. 1995. Stocna tikva - zaboravjljene krmna kultura. Zbornik radova Instituta za ratarstvo i povrtarstvo Novi Sad 23:529-537.
- Berenji, J. 1999a. Tikve - hrana, lek i ukras. Zbornik radova Instituta za ratarstvo i povrtarstvo Novi Sad, 31:63-75.
- Berenji, J. 1999b. Proizvodnja i koriscenje uljane tikve (Cucurbita pepo L.). Zbornik radova 40. Savetovanja o proizvodnji i preradi uljarica, p. 303-308.
- Berenji, J. and Gy. Karlovits. 1995. Az olajtok szarmazasa, rendszertana es alaktana. Olaj, szappan, kozmetika 44(2):54-59.
- Momirovic, N., S. Oljaca, G. Vasic, D. Kovacevic and Z. Radosevic. 1998. Effects of intercropping pumpkins (Cucurbita maxima DUCH.) and maize (Zea mays L.) under different farming systems. Proceedings of the 2nd Balkan Symposium on field Crops, p. 251-254, Novi Sad.
- Popovic, M. 1971. Prilog poznavanju kulture tikava (Cucurbita sp.) u nas. Savremena poljoprivreda 19(11-12):59-72.
- Sabo, A., J. Berenji, J. Stojkov and J. Bogdanovic. 1999. Phamacodynamic effect of pumpkin seed oil (Oleum cucurbiaceae pepo) in patients with adenoma prostate. Abstracts of the 2nd European Congress of Pharmacology, Budapest, 3-7, July 1999, p. 360 s,
- Schiulcher, H. 1986. Cucurbita-species, Zeitschrift fur Phytotherapie 7(1):19-23.