Culture of Feijoa Trees

New Zealand Journal of Agriculture, Volume 84, Issue 4, 15 April 1952, Page 291

Culture of Feijoa Trees

.. .| N. recent years several sub-tropical fruits have been grown and marketed in New Zealand. •-?Among them is the feijoa, sometimes called the New Zealand banana, a fruit which ripens-in late./ autumn, when little other fresh fruit is available. Apart from the useful • fruit it bears, the. feijoa is proving very popular as a hedge or for an ornamental driveway. The culture of the trees is : described in this article by F. L. Bailey, Orchard Instructor, Department of Agriculture, Tauranga.. The fruit may be used for a variety of culinary and dessert purposes, some recipes for which are given in an article on page 336.

THE feijoa (Feijoa sellowiana Berg.) •i * belongs to the botanical order Myrtaceae, a family of plants in which many of the species are noted for their pleasant aroma. It grows naturally in the sub-tropical regions of South . America, where it thrives in a climate free from great extremes of temperature and having an annual rainfall of 30 to 40in. Edouard Andre, a noted French horticulturist, on his return to France -in 1890 from a visit to South America introduced the feijoa to the French Riviera. There it grew and fruited remarkably well, and it was introduced later to the United States of America and other parts of the world. . Cultivation in New Zealand One of the earliest records of the introduction, of the feijoa into New Zealand was about 1908, when an. Auckland nurseryman .in business at that time imported plants from Australia. It was not until about 1930,

however, that it came into prominence, when the plant was advertised by nurserymen as an ornamental evergreen tree. It was described as growing to about 15ft. high with colourful red and white blossoms resembling those of the pohutukawa, and having attractive green foliage with a silvery undersurface and bearing a useful fruit. At first the feijoa was planted more as an ornamental novelty than as a commercial proposition. With the improvement by selection in quality and size of fruit and the propagation of named varieties small commercial plantings have been made in New Zealand, mostly in the citrus-growing districts of the North Island in conjunction with other sub-tropical fruits. The profitable life of a tree is difficult to estimate, for so far it appears that no insect pests or diseases have been recorded which cause structural damage to the species. In isolated instances very old trees are growing in parts of the Bay of Plenty which

have received little cultural or manurial attention and they continue to bear satisfactory crops of fruit. From the evidence available it seems that the feijoa is not short lived, and will grow and bear fruit for many years without special attention. The Fruit The variation in the size and shape of the fruit from seedling trees is considerable, but from the so-called varieties the bulk of fruit is usually more uniform in appearance. On the tree the fruit is green overspread with a whitish bloom, but it becomes yellowish green sometimes accompanied by bronze markings when ripe. The skin is thin and encloses a layer of whitish granular flesh about Jin. thick which surrounds a translucent jellylike pulp where small seeds are embedded. When ripe the fruit has a characteristic aroma and a delicate flavour claimed to resemble pineapple and strawberry; in New Zealand it is sometimes referred to as the New Zealand banana. It may be eaten raw, cut up and used in fresh fruit salads, preserved by bottling, or used for making jam. Fruit of the Coolidgei, a named variety, has been found to have a very high vitamin C content. That is not the case with all feijoa fruits, as, from tests carried out for vitamin C content, it is apparent that fruits from some seedlings contain a relatively low percentage.

Location The feijoa is commonly called a sub-tropical fruit, which gives the impression that it can be grown only in a warm climate. The plant actually is hardy, for it has been known to withstand 20 degrees of frost without injury. It also resists winds remarkably well and has been used frequently for shelter purposes in many parts of the Auckland Province in orchards and domestic gardens where low-growing windbreaks are required. It thrives best in a mild climate free from excessive humidity and high temperatures and having an annual rainfall of between 30 and 40in. At present the fruit is grown commercially in the Kerikeri, Auckland, and Tauranga districts, which are regarded as the sub-tropical fruit-growing areas of New Zealand. Owing to the hardiness of the plant there appears no reason why it should not be grown commercially in other recognised fruit-growing districts where climatic conditions in winter are not excessively severe. In home gardens it should be possible to grow feijoas in most places in New Zealand with the probable exception of those which have a wet climate or unsuitable soil conditions. Soil A good sandy loam rich in humus is very suitable for growing feijoas. They may be grown successfully also on clay soils which have been improved byi the addition of humus; that may be done by sowing cover crops such as lupins or oats, which should be turned under when ready. Heavy soils which waterlog during wet spells should be avoided, as the feijoa will not tolerate “wet feet”.

.....,. A warm aspect is desirable, but the situation seems to be of little importance provided the soil is well drained. Shelter / In New Zealand usually small areas are grown as an adjunct to citrus and other sub-tropical fruits or on small holdings growing miscellaneous horticultural crops. Although the plants resist winds well, they grow and produce better-quality fruit if in a sheltered position. The provision of shelter in most cases is of little importance, because feijoas, being. a minor crop, receive sufficient shelter from the crop - established for the main horticultural undertaking. Unlike other sub-tropical fruits ■ they. may be -planted to advantage on the more exposed portions of a grower’s holding. . Varieties Most of the feijoa trees planted in New Zealand have been raised from seed, and the seedlings have produced fruit which has shown great vari-

ability in size and shape. Little information has been recorded about the importation of named varieties of feijoas into New Zealand, but it is known that a single tree each of the varieties Coolidgei, Choiceana, and Superba were imported by an Auckland nurseryman some years ago. The Coolidgei and Choiceana trees are still growing and fruit annually, but the Superba tree died at an early age before fruiting. . A large number of seedlings were raised from seed of the imported Choiceana, and it appears that from the progeny of that variety four trees were selected because of their desirable qualities and each given a variety name. The names are Coolidgei, Superba, Triumph, and Mammoth. The name Superba was given to one of the seedlings because the fruit corresponded with the description of that variety in overseas catalogues. For commercial planting it is now customary to propagate the so-called varieties vegetatively; details are dealt with later in this article. The table below gives a short description of each variety at present offered for sale by nurserymen. The pollination requirements of different plants vary. Some are said to be self-sterile and others self -fertile. As no definite information on. this aspect can be given, it is advisable to plant several plants or varieties together to ensure adequate pollination. It has been asserted that the variety Coolidgei is self-fertile, since isolated trees are known to have borne regularly. Propagation For successful commercial fruit production it is essential that all trees planted should bear regular crops of fruit of a size and type desired by the market. Seedling trees do not fulfil these conditions satisfactorily, as observations of plants so raised have indicated that there is too much variation both of size and shape in the fruit. The most reliable method of raising young trees is to propagate them vegetatively. That may be done by : striking cuttings, by layering, or by grafting on to seedling stocks. Whatever method of propagation is used, trees bearing desirable, well-shaped fruit should always be selected from which to take propagating wood.

Cuttings

To raise trees from cuttings, lateral growth 4 to Bin. long should be selected, and with a downward pressure of the thumb at the base of the lateral it should be removed from the parent tree with a “heel”. Thin laterals produced on the lower and shaded parts of the parent tree seem to root more readily than the more sturdy shoots growing on the exposed upper portions. The cuttings are not shortened and from 2 to 6 of the end leaves are left attached.

In northern districts the cuttings root readily when planted during any of the winter months, but in the more southern districts it is advisable to plant in late autumn or early winter

before the onset of cold weather to secure satisfactory rooting.

Light sandy loam which has free drainage is the best soil in which to strike the cuttings. The nursery bed should be located in a- sunny, wellsheltered position and the soil should be well worked before planting. A mixture of equal parts of superphosphate and blood and bone applied at the rate of Jib. a square yard to the nursery bed will . assist , root development. In the Auckland Province successful results have been achieved in striking the cuttings outdoors. Layers Feijoas propagate readily by layering. The lavers are best made in autumn, small branches of the parent tree being taken near the ground and lowered into scooped-out depressions in the soil. The depression should be about 3 or 4in. deep and the layer pegged down, after which the • soil should be drawn over the layer for a length of about 6in. The branches used for layering should be of sufficient length because the wood is very brittle and if a branch is too short it will invariably snap oft when pressure is exerted when lowering it into the soil depression. Risk of breaking may be minimised by cutting a slight shaving about 2in, long from the branch where roots are desired, instead of making a partially transverse cut as is normally done when layering most other plants. Provided the soil is moist, roots develop on the layers. in spring and the layers may be severed from the parent tree during . the. following, autumn. The plants should then be grown on in a nursery bed for another year before being planted in their permanent positions. Grafting Few feijoas have been propagated in New Zealand by grafting, but recently some nurserymen have raised a satisfactory type of tree by that method. The stocks used for grafting are feijoa seedlings. To raise stocks well-grown, fully-ripe fruit should be selected and the seed extracted by squeezing the pulp out of the fruit into a container and covering it with water. The pulp should then be allowed to ferment for about 4 days, after which the seed should be washed in a fine sieve and dried.

The seed is small and may be sown thinly in a seedling tray under glass about the end of May. A light, sandy, sterilised loam is the most suitable soil for seeding, and when sown the seed requires only a light covering of finely sieved soil. To ensure good germination the surface soil of the seedling tray should not be allowed to dry out. As soon as the young plants have grown their second leaves they should be pricked out. and when of sufficient size they may be lined out in nursery rows.

For ease of handling the seedlings should be at least the diameter of a lead pencil when grafted. Usually a stock is 2 years old before it is in a suitable condition for working. Grafting is done in August-September when the shoot growth has become rigid and before spring growth begins. The grafting scions are taken from any piece of mature wood which will give 5 to 6 buds and all leaves are removed. The whip or tongue method of grafting gives the most satisfactory results. Full information about grafting is given in Department of Agriculture Bulletin No. 285, “Grafting of Fruit Trees”, which is obtainable free from the nearest office of the department. When the graft has been fitted the scion is bound in position with raffia, but no grafting wax or other sealing material is applied to the union. The grafted seedlings are then placed in a cold frame and planted so that only two buds at the top of each scion are above ground. They are left in the cold frame until autumn, usually March, when growth has matured, and then planted out in nursery rows until big enough to be set out in their permanent positions. - Feijoas may be transplanted without difficulty if the plants are wrenched about a month before being lifted. Soil Preparation and Planting Before the trees are planted the soil should be well worked so that root development may progress without check. As the feijoa has a mass of shallow fibrous roots, thorough initial cultivation is necessary, because after the trees are planted deep cultivation near them must be avoided or. valuable fibrous feeding roots may be destroyed. Plants are best set out during June or July to allow them time to become

established and better able to withstand dry periods during the following summer. To give the trees a good start a mixture of equal parts of superphosphate and blood and bone at the rate of lib. a tree should be applied to the soil in the planting positions and well mixed with the soil some 3 or 4 weeks before the trees are planted. Before each tree is planted the rooting system should be examined and any rootlets which are damaged or misshapen should be pruned off. In planting it is important to tread the soil firmly around the roots so that the young 'trees have a firm anchorage. Planting Distances Planting distances between trees will vary according to whether they are planted in a block or in hedge rows. In block plantings it is advisable to plant the trees on the square system to facilitate orchard management. They should be set out in rows 15ft. apart with 15ft. between trees; at these distances about 190 trees an acre will be required. Although there are few, if any, old plantings of feijoas in New Zealand, it appears from present indications that if trees are planted in blocks at distances less than 15ft. apart each way, overcrowding will result eventually. When grown as a hedge bordering a driveway or along an orchard boundary for ornamental or low-shelter purposes the trees may be planted from 4ft. 6in. to Bft. apart, according to individual requirements. Pruning For the first 2 years after being planted the trees should be encouraged to produce vigorous growth and at the same time a strong framework should be built up. In block plantings, where fruit production is the main consideration, shaping of the trees is important. In a well-shaped tree the fork (where the main limbs branch) should be at least 12in. above the ground; all shoots which develop below the fork should be removed periodically.

When feijoas are planted as a hedge the pruning of the , young tree to encourage the' development of a single trunk before the tree is allowed to branch is not always essential. It is, however, considered advisable to develop a single trunk, for trees so shaped grow into sturdy specimens and cultivation and harvesting operations are greatly facilitated. When the foundation of the young tree is being built 5 to 7 main branches that will develop into a shapely, balanced head should be chosen for the main arms. If necessary, these may be shortened back in the early stages to induce lateral growth and preserve the symmetry of the tree. Once the tree has developed a shapely, balanced head, very little subsequent pruning is necessary or desirable; all that may be required is a possible thinning out or shortening back of straggling lateral growth. Excessive thinning of lateral growth should be avoided, for the wood is very brittle, and if pruning is overdone, severe breakages are likely to occur even if trees are exposed to moderate winds. Manuring Some growers believe that little if any manure is required to produce fruit; some believe its moderate to heavy use stimulates growth at the expense of fruit production. That may occur if heavy applications of inorganic nitrogenous fertilisers are used regularly, but more probably failure to set fruit is due to propagation of the plants from seed and to lack of pollination. The causes of failure to set fruit may be minimised by raising trees vegetatively and planting different varieties together. Many different mixtures of fertilisers are used by growers of feijoas, but on most soils regular applications of a mixture containing blood and bone and sulphate of potash have produced satisfactory growth and crop yields. The quantity of manure applied each year varies with the soil type, the age of the trees, and quantity

of fruit they produce. As a guide about lib. of a mixture containing 5 parts of blood and bone and 1 part of sulphate of potash by weight should be applied for each year of the tree’s age from the time of planting up to a maximum dressing of 10 to 151 b. per tree for mature trees. The manure should be applied in two dressings. The first, containing the sulphate of potash and about half the blood and bone, should be broadcast around the trees in August. The remainder of the blood and bone should be applied at the end of December or early in January and lightly hoed into the soil. Lime Requirements It has been stated frequently that the feijoa prefers an acid soil and that it will not tolerate applications of lime. From the general growth of feijoas in New Zealand there is little evidence to support this claim, as plants grow and fruit well on land that has a fairly high pH value. (The pH value of a soil is determined by its acid or alkaline content; pH 7 represents a neutral soil.) On heavy soils applications of lime improve the soil texture and its use on such soils is beneficial for growing feijoas. On light soils lime applications seem of little importance to the plants. The excellent growth made by 6-year-old trees growing on land which has a pH of 6.2 can be seen from the photograph above. General Maintenance Feijoa trees have a mass of fibrous feeding roots near the soil surface and may be damaged easily by careless use of implements. Maintenance cultivation close to the trees should be only deep enough to control weed growth and conserve soil moisture during spring and summer. Where clean cultivation is practised the growing of cover crops will enrich the organic content of the soil. Blue lupins or oats provide good humus and during summer or early autumn

should be sown with superphosphate at the rate of 2 to 3cwt. per acre. The crop should be turned in during winter, preferably with a rotary cultivator. On light soils in some of the subtropical fruit-growing districts where some orchards are maintained in permanent pasture or green crop, the sward should be mown regularly in spring and summer to reduce moisture transpiration. The mowings, which form a valuable mulch, should be collected and placed on the cultivated squares beneath the trees. Pests and Diseases At present in New Zealand the feijoa is attacked by few insect pests and diseases and control measures are a minor item in the production of the crop. Leaf-roller Caterpillar The grub of the leaf-roller caterpillar (Tortrix spp.) is active during late December and early in the new year, when it may be found attacking the - foliage and young shoots of the trees. It eats holes in leaves and frequently chews out the tender growing tips of laterals, but it seldom damages the fruit. The caterpillars of a bag worm moth may also cause leaf injury by eating small irregular-shaped holes in the leaves. These caterpillars carry a conical “house” around with them and are conspicuous on the foliage during late spring. Control of the caterpillars may be obtained by spraying the trees with arsenate of lead at l|lb. to 100 gallons of water. Applications should begin about mid-December and be continued at -weekly intervals until February. Hard Wax Scale Hard wax scale (Ceroplastes sinensis) is common on feijoa foliage and attacks a wide range of plants. The adult scales are cone shaped and greyish white and are capable of producing large numbers of eggs.

The small, star-shaped’ young scales are usually found on the upper surface of the leaves and are most noticeable during April and May. Sooty mould is associated with this scale and infection of both sooty mould and scales may become severe if control measures are neglected. Control should be directed against the young star-like stages by applying a 1| per cent, summer oil spray to the trees during May. Leaf-spotting Fungus A leaf-spotting fungus, Sphaceloma sp., is occasionally found attacking the foliage of feijoas. This fungus belongs to .the same group as that causing verrucosis on lemons. . Should the disease appear to an extent requiring control measures, Bordeaux mixture 3 : 4 : 50 should be applied at first signs of spotting. Several sprays at 2- to 3-weekly intervals may be necessary to secure full control. Harvesting The first fruits usually mature toward the end of April and harvesting continues during May; in some seasons, usually after a long dry spell, fruit ripens earlier, about the second week in April. The fruits fall to the ground when mature and are not picked from the trees as most other fruits are harvested. They should be collected daily and not left exposed to the sun any longer than necessary, as scalding of the fruit may occur. Little if any bruising occurs to the fruit when it falls, but to minimise any risk of damage it is advisable to maintain either a loose surface soil mulch or straw mulch under the trees. When the fruit falls it is very firm and the flesh lacks flavour. It is unsuitable for use until the colour changes to a yellowish-green, when it produces a pleasant aroma and becomes’slightly soft. Until feijoas reach that stage of maturity they are

unfit to use either for culinary or dessert purposes. Fruit not required for immediate use should be stored in a cool, draught-proof shed to prevent withering and be marketed before it becomes soft. Under suitable storage conditions fruit may be held for about a month. Commercial growers should guard against holding feijoas too long; when packed for market sufficient life should be in the fruit to allow it to reach the consumer before there is any chance of its deteriorating. Packing No standard package for feijoas has been adopted, but the No. 8 flat tomato case in the schedule of standard packages in the New Zealand Grown Fruit Regulations, 1940, has proved a satisfactory container. This case, which has inside measurements of 4 jin. . x 12in. x 16in. and holds about 201 b. of fruit, is recommended. If necessary this case may be cut in halves, giving an inside measurement of 4|in. x 6in. x 16in.; approximately 101 b. of fruit may be . packed in half cases. The fruit should be of the same maturity when graded to size and should be packed on the diagonalpocket system, which places the fruits in any layer in the spaces between the fruit in the layer beneath. Packed on this system the fruit presents an attractive appearance when the case is opened and bruising or damage to the contents during transit is reduced. The use of mauve lining paper contrasts with the greenish colour of the feijoas, enhances the appearance of the package, and frequently adds to the market value. For sending feijoas to distant markets the use of corrugated top and bottom pads will give the fruit added protection against damage. Neat branding of the railing or shipping mark on both ends of the case simplifies any sorting necessary during transit and frequently avoids unnecessary handling of the fruit. To prevent possible misdirection, care should be taken to use correct abbreviations for railway stations to which consignments are dispatched; the Railways Department will provide information about recognised abbreviations. The name of the fruit and some indication of the size, such as “large”, “medium”, or “small”, should be stamped or stencilled on one end of the package. Provided soil and climate are suitable, feijoas grow without special attention and production costs are the lowest of any subtropical fruits produced in New _ Zealand. If , care is taken in the selection of trees for planting, there appears to be no reason why they should not yield a payable return to the grower. References “The New Zealand Journal of Agriculture”, volume 73, page 465, F. Sydenham (1946). “Manual of Tropical and Subtropical Fruits”, pp. 292-299, W. Popenoe (1924). "New Zealand Journal of Science and Technology”, “Observations on Seedling Feijoas (Feijoa sellowiana Berg.) at Mount Albert Auckland”, agricultural section, volume 28, number 5, H. M. Mouat (1947).

Variety Tree growth Fruit shape Fruit epidermis Size Coolidge! (imported) Strong, upright Oblong Moderately crinkled Medium Coolidgei (N.Z. raised) Strong, upright Oblong to elongated Moderately crinkled Medium Choiceana (imported) Medium, spreading Spherical to oval Moderately smooth Medium to small Superba Medium, spreading Spherical to slightly Moderately Medium to small (N.Z. raised) Medium, spreading and straggly Spherical to slightly oval Moderately smooth Medium to small Triumph (N.Z. raised) Medium, upright Short,oval, and plump, less pointed than Coolidgei Smooth Medium to large Mammoth (N.Z. raised) Strong, upright Oval, similar to imported strain of Coolidgei Moderately wrinkled Large (up to 8joz.)

VARIETIES OF FEIJOAS