DESCRIPTION AND USE OF QUINCE FOR FRUIT PRODUCTION
V. Nuzzo, B. Dichio and C. Xiloyannis
Dipartimento di Produzione Vegetale, Universita' degli Studi di Potenza
BOTANICAL SPECIES: Cydonia oblonga L.
HABITAT. The quince is an ancient fruit tree species, whose center of origin is been accepted to be a large area in Asia Minor and Caucasus. Quince for fruit production was known and cultivated from Greek and Romans people, the name Cydonia is the ancient name of the Crete town of Chania.
Quince is cultivated in Mediterranean countries, in Germany, in United Kingdom of Great Britain, in the Eastern-Europe countries (Bulgaria, Rumania, Hungary, ect.), in Russia and in South America.
In Mediterranean countries quince generally is grown without irrigation in zones with more than 800 mm/year of rainfall and where the frequency of rainfall during summer is high. In fact, quince is very sensible to soil water deficit because it has a shallow root system.
Optimum average temperature should be about 15 °C. The winter hardiness is very good (cv ''Aiva Servenaia' about -35 °C). During 1985 (January) winter frost damaged apple and pear flower buds in the area of Piacenza (Italy), but no damage was observed on quince buds. The chilling units requirements are medium to low.
As regard to the soil, is kwon the sensitivity to high level of active limestone (should be less than 4 - 7%), but is quite resistant to acidity (pH = 4) and humidity.
GENETIC VARIABILITY. The species Cydonia oblonga is splitted by botanist in 5 sub-species: C. oblonga marmorata Dipp., C. oblonga pyriformis Kirchn, C. oblonga maliformis Mill., C. oblonga lusitanica Mill., C. oblonga pyramidalis Dipp.. The cultivars of quince for fruit production should derive from C. oblonga maliformis Mill. (with apple shape fruit), C. oblonga pyriformis Kirchn and C. oblonga lusitanica Mill. (with pear-shape fruit). The varieties with apple-shaped fruits are preferred by industries because the fruit suits better to mechanical peeling.
The genetic variability is quite high for most traits. Different authors, although differences among certain cultivars may be small, have described more than 100 varieties. We must consider, though that the many synonymies and the marked polymorphism typical of fruits and leaves make for a difficult characterisation of the same varieties. In Italy, a study of 22 varieties has showed a great variability in important traits as vigour, productivity, flowering, harvest season, fertility, fruit weight and shape, fruit quality and composition.
Some varieties are self-incompatible and they must be pollinated for production. Anyhow, also self-compatible varieties take advantage of cross-pollination. Only a few varieties are parthenocarpic.
PLANT. The natural shape of quince is a shrub or bushy-like, without thorns, with deciduous leaves, alternate on the shoot. Shoots are brown with pale or dark-green tonalities covered by hair more o less abundant, but easily removable. Internodes are of medium length (6-7 cm) with lenticels. Root system is quite shallow and does not permit a good anchorage for plants. Nevertheless, quince is one of the most important rootstock of pear.
In the North Hemisphere, the annual cycle generally starts in March-April with the breaking of vegetative buds and after 1 month with flowering. Flower bud induction generally occurs in July-August and flower bud differentiation occurs in September-October. Plants propagated by self-rooted cuttings or grafted on seedlings have a first harvest after the second growth cycle and a regular yield could be reached in 4-5 years. The period of regular cropping is about 25-30 years. In Italy a good yield is about 40-60 t/ha in the Po valley, and 13-30 t/ha in South Italy.
LEAVES. Quince leaves show a remarkable variability depending on their position and the vigour of the shoot. Generally, the central leaves of the shoot of different varieties can be grouped in 4 typical shape: obovate, elliptic, oval, and round. The length of the leaves ranged from 7 to 14 cm, while the width is included between 5 and 10 cm. The upper face generally is glabrous, while the inferior one is hairy. Other leaves characteristics that allow to distinguish varieties are: shape of tip (acute or obtuse), of the edge (dentate, entire or waved) and length of petiole.
FLOWERS. Flowers are white or rosy, single and located at the tip of tiny shoots. When the flower is completely open the diameter in the different varieties ranges 3 to 7 cm. Each flower has 5 sepals, 5 petals, 20 stamens and 5 pistils corresponding with 5 ovarian loculus that, on the whole, can contain up to 90 seeds. The other characteristics that distinguish flowers between the accession are: size, colour, shape of the petals (rounded, squared, rectangular, ovate and elliptic), spacing between petals and position of the stigma compared to anthers.
FRUITS. Quince fruit is a pome type with numerous seeds. Fruits are big with a characteristic fragrance, they show variable dimensions and also asymmetric shapes. The skin is covered by an abundant hair that disappears with fruit ripening. In this phase it gets a goldish-yellow colour, more or less marked varying with cv. The white-yellow pulp is easily oxidised to air exposition, is firm and often rich in schlerinchymatous cells and generally is acid and astringent, so it does not suit for fresh consumption. Ripening normally occurs from September to the second decade of October. The fruit characteristics that allow distinguishing varieties are: shape of fruits, dimensions, shape of stalk end, calyx cavity, size and shape of seeds.
USES. In the past quince was an important fruit trees species. The fruits are at the present given to the industry of transformation, and thus only a small portion is consumed as fresh fruit. The most important utilisations are for mustard production, alimentary preserves, jelly, liquors and distilled products.
The authors are grateful to Dr. Costantinos Tsipouridis, Prof.ssa Cristina Bignami and Prof. Alessandro Roversi for their suggestions.