Quince, Cydonia oblonga
, is a bush-like deciduous tree in the family Rosaceae grown for its edible fruits. The tree has crowded, gnarled branches and a crooked growth habit. The leaves have a smooth upper surface and hairy lower surface. The tree produces single white-light pink colored flowers on tiny shoots and a large, fragrant, pome fruit. The fruit is initially covered in dense gray-white hairs but these disappear as the fruit ripens. The ripe fruit is a golden yellow color and resembles a pear or apple depending on variety. It has a soft, yellow pulp with a grainy texture protected by a thin skin. Quince trees can reach heights of 5–8 m (16–26 ft) and can live for periods in excess of 50 years and have an economic lifespan of approximately 25 years. Quince originates from Asia Minor.
Quince fruits are consumed fresh or may be used to make jams and jellies.
Quince trees grow well in a wide range of climates and soils but the plants shallow root system make it susceptible to drought or a low availability of water and additional irrigation may be required. Quince should be planted in full sun and will grow optimally at temperatures averaging 15°C (59°F). Quince trees are more tolerant of wet soils and drought than apple trees and, compared with other fruit trees, has good cold tolerance, being hardy to temperatures between -15 and -25°C (5 and -13°F respectively). Quince trees are easily damaged by strong winds and should be planted in a sheltered location which will also protect them from rapid temperature fluctuations which is also detrimental to their growth.
Quince trees are usually propagated from hardwood cuttings or by budding onto a quince rootstock. Seeds can be grown but will not breed true to type and should not be used for commercial purposes where fruit quality is very important. Some varieties are not self compatible and require another variety for successful pollination and fruit production. Quince trees should be spaced 5–6 m apart (16–20 ft) apart, allowing 4–5 m (13–16 ft) between rows.
General care and maintenance
Quince trees are susceptible to fire blight and should not be fertilized excessively with nitrogen as this promotes vegetative growth which makes the trees more susceptible to the bacterium. Suckers should be removed by pruning from the tree in winter or early spring. Trees should be pruned in winter to thin out fruiting wood and stimulate new growth. If fruiting wood is pruned properly then fruits should not require thinning when the trees are bearing. Quince will benefit from regular deep watering during the summer months.
Quince fruits should be harvested when they are mature but not full ripe. Fruits will continue to ripen off of the tree and by harvesting in this manner, losses from fruit dropping from the tree are reduced. Fruit should be cut from the tree using a sharp knife as pulling them can cause damage to the skin.
Common Pests and Diseases
Blossoms wilting and dying; shoots shriveling and dying; cankers on branches; plant appears as if it has been scorched by fire; watery exudate may be present on infected areas
Cut out diseased wood; treat with Bordeaux mixture or approved fixed copper materials for organic production; streptomycin or copper application to blossoms may be necessary to prevent spread
Death of young blossoms and associated twigs and leaves; small tan cankers with dark margins on twigs; gummy exudate at base of flowers; brown spore masses on flowers in humid conditions; infected fruit usually exhibit a rapidly spreading brown rot but may also take the form of small necrotic spots; infected fruits usually remain attached to the tree
The currently most effective method of controlling brown rot is through the application of appropriate protective fungicides timed so that they are applied when the susceptible flower parts are exposed or after a wet period; avoiding sprinkler irrigation protects the leaves and flowers from wetness that promotes the disease. Cultural control methods include: removing mummified fruit from tree, pruning infected twigs and reducing plant stress by providing adequate levels of water and fertilizer
Leaf blight (Leaf fleck)
Dark red spots on leaves; brown spots on leaves; leaves dropping from plant; small, raised purple spots with white centre on leaves; dark brown spots on leaves; no fruit produced; tree defoliation
Remove all fallen leaves from orchard in Fall; avoid overhead irrigation; applications of appropriate fungicides may be required; orchards treated for scab are usually free of leaf blight