Pome Fruit (Apples and Pears)

Various spp.

The summary information below has a focus on sub-tropical members of the pome fruit group (also called pip fruit), namely low chill apples (Malus x domestica) and European pears (Pyrus communis) and the Asian or nashi pears (Pyrus pyrifolia), as opposed to the temperate climate quince which is not eaten fresh. A separate entry is given for loquats.

Origin:

The domesticated apple is thought to be derived from several wild species native to Central Asia, while pears are probably from Western China. Even though they’ve been cultivated for millennia, the varieties we’re all familiar with today were only selected and developed in the last hundred years.

Climate:

Pome fruits traditionally require temperate climates (900-1100 chill hrs), but their widespread popularity has resulted in development of many low chill alternatives (150-500 hrs) to extend the range of cultivation and availability. Dormant trees are very frost tolerant but flowers and young fruit will be damaged. They are moderately drought tolerant.

Plant Description:

They are deciduous trees with apples 2-6m tall depending on rootstock while pears are slightly larger.

Relatives:

Rosaceae Family, related to berry fruits, strawberries, stone fruit, medlar and capulin cherry.

Soils:

On seedling rootstock apples and pears can tolerate a wide range of soil types, but nashis prefer lighter fertile soils.

Propagation:

Mainly by budding and grafting. With apples, a wide range of rootstocks for disease resistance, control of vigour etc is used. For nashi, rootstocks are mainly seedlings or quince; other Pyrus species are used in poor soils.

Cultivars:

There are probably thousands of cultivars worldwide but a few dozen of these dominate commercial production. Some low chill varieties that you may be able to source here are: apple – Anna, Dorsett Golden and Tropic Sweet; pear – Flordahome and Hood; and nashi – Hosui, Nijisseiki, Chojuro, Shinseiki and Ya-Li.

Flowering and Pollination:

Flower buds are produced on tips of shoots or on spurs of 2-year-old or older wood, and produce 5-8 flowers and a similar number of leaves. The hermaphrodite flowers contain 5 sepals, 5 petals, about 20 stamens and 5 pistils. Most cultivars are self-incompatible, and while some are partly self-fertile, cross-pollination will improve fruit set. Often, specific pollinator pairs are required. Bud burst is in spring with pollination by insects, mainly bees.

Cultivation:

Plant in full sun. Lack of water reduces yield but too much can reduce fruit storage duration. Best pH is 5.5-6.5 but can still grow with 4.5-8. Good nutrition has to be maintained, but excessive N will favour vegetative growth instead of reproductive.

Wind Tolerance:

This is only moderate with sheltered sites preferred, more so for nashi. Trellising and espaliers can assist.

Pruning:

Often grown in the open vase form, with selection of 3-4 main structural branches when young. Mature plants will require annual checking to maintain light penetration and size. When well pollinated, fruit thinning will improve fruit size and reduce the risk of alternate bearing.

The Fruit:

Apples and pears are well known by all and hardly need description, but nashi less so. The latter are more like an apple in shape and texture. Pears, and especially nashi, have flesh containing variable amounts of stone cells. None of these pome fruit is particularly rich in vitamins or minerals. They contain 7-10% sugars.

Fruit Production and Harvesting:

With apples, time to first harvest is 1-2 years and full production in 6-9. With pears and nashi, the corresponding periods are 4-6 and 7-10, depending on rootstock. Pears are picked at maturity while still firm whereas nashi are left to ripen more fully on the tree. All these fruits can be cold-stored for lengthy periods.

Fruit Uses:

Usually eaten fresh, but also processed in many forms eg dried, canned, juiced, baked foods and cider.

Pests and Diseases:

Numerous, and can involve Medfly, codling moth, mites, thrips, scale, powdery mildew, bitter pit, collar and crown rot, black spot and stony pit.

Comments:

It is essential with choice of cultivars that requirements for chill hours and pollination will be met.