Fruit Growing at Kerikeri

New Zealand Journal of Agriculture, Volume 86, Issue 2, 16 February 1953, Page 147

Fruit Growing at Kerikeri

By

J. A. CEDERMAN,

Horticultural

Instructor, Department of Agriculture, Kaikohe

THE fruit growing district of Kerikeri, on the east coast of the North Island some 50 miles north of Whangarei, lies at the head of the Kerikeri Inlet in the centre of the picturesque Bay of Islands. The land is undulating with broad, flat-topped ridges sloping down to tidal inlets, rivers, and small streams, which subdivide the district.

ORIGINALLY part of a sheep run of about 8000 acres known as the Riddell Estate, the more suitable sections were subdivided in 1927 by the North Auckland Land Development Company into blocks of 20 acres for orchard settlement.‘ Of these areas, 5acre plots were planted as quickly as possible with citrus trees and passion fruit. The remaining 15 acres, some of which were unsuitable for planting in citrus, were left in gorse, bracken fern, or pasture.

From 1927 the district has developed steadily, until today over 600 acres have been planted in commercial orchards. Most of the present orchards are only about 5 acres, owing to further subdivision of -many of the original blocks.

Climate and Soils

The climate, which lies between warm temperate and sub-tropical, favours the production of certain species and varieties of citrus and other sub-tropical fruits. In normal winters only slight frosts are experienced. The topography of the district and the location of streams and tidal inlets influence the severity of these frosts. Winds are normally of low to moderate velocity. Total annual hours of sunshine average about 2120, a total which compares favourably with that of other citrus growing districts.

The soils are well drained, friable, mid-brown loams of volcanic origin which are easy to work and when cultivated break down to a fine tilth. The top soil varies in depth from 4 to 18in. and overlies a compact subsoil of dull brown, granular clay.

History

After the subdivision properties were taken up ’ largely by purchasers from overseas, mainly British residents in China. The North Auckland Land Development Company issued pamphlets setting out schemes whereby properties would be developed and maintained until they reached production, but development costs were often underestimated and returns fell short of expectations.

The residents were all inexperienced fruit growers and looked to the company’s “experts” for advice.

Passion fruit was the main crop produced in the first few years. Various companies contracted to take all supplies at prices ranging from Id. to 2d. per dozen, but nearly all these companies were unable to meet their commitments to growers. Serious fungous and bacterial diseases became rampant in the crops, control measures were difficult, and growers lost interest in passion fruit growing.

First Citrus Plantings

First citrus plantings comprised chiefly trees imported from New South Wales, the varieties selected being Washington Navel , and Valencia oranges, and Lisbon and Eureka lemons. In many instances the growth of these trees was disappointing, because of inadequate soil preparation, lack of shelter, dry seasons, and, in some instances, under-nourishment. . When these trees began to bear the quality of much of the fruit did not come up to expectations. Oranges were thick skinned, of poor juice content and flavour, and tended to dry out when mature. The prices obtained for lemons were poor. Production per tree and per acre was also very disappointing.

The outbreak of citrus canker, a serious bacterial disease, in 1937 temporarily retarded the growth of the industry. Eradication measures included bare poling and in some instances the. removal and burning of hundreds of trees.

These setbacks caused growers to search for citrus varieties and other sub-tropical fruits more suited to local conditions. Much better results are now being obtained in tree growth,

fruit quality, and yields from the newer plantings of Meyer lemon, Morrison and Wheeny grapefruit, tree tomatoes, and Chinese gooseberries. Also showing commercial promise are several new varieties of sweet orange and mandarin, which are being planted in good numbers.

Production of Fruit

Present orchards at Kerikeri are

nearly all planted with a mixture of citrus and sub-tropical fruit. The properties are fairly uniform in size, but no two orchards are planted with all of the same varieties or return similar

production figures.

With citrus, the rootstock used has a great influence on tree growth, productivity, and fruit quality. Rough lemon or Citronelle, the stock used for all the early plantings, has proved quite satisfactory for grapefruit. and lemons, but sweet orange and mandarin varieties budded on this stock

have been inconsistent in their cropping and fruit quality is unreliable.

The Island sweet orange seedling has now largely replaced Citronelle as a rootstock for lemons, grapefruit, and to a less extent sweet oranges. Poncirus trifoliata stocks are being widely used for the propagation of most sweet orange and mandarin varieties. Vigor-ous-growing varieties worked on to this stock normally carry consistent crops of fruit of very good quality. Other rootstocks, including Yuzu and Morton Citrange, which show promise, are being tested in the district.

At present there are 132 registered orchards at Kerikeri. These properties may be classified as follows:

Orchards with no production 10 Young orchards not bearing 11 Part bearing . . . . . . 48 Reasonable production . . 50 Full bearing . . . . . . 13 Total .. .. .. .. 132 The orchards listed with no production are neglected; nearly all have absentee owners. Full-bearing orchards are few because there has been extensive interplanting between tree rows and replacement of uneconomic

varieties in many older-established groves. Of the 132 orchards 51 are in firstclass condition, 57 are fairly good but could be brought up to a higher standard, 19 are poor, owing to neglect, but could be improved under better management, and 5 are seriously damaged by continued neglect and it would be uneconomic to bring them back into production. The production figures for the past 5 years (see table below) show a significant crop increase for Meyer lemons, New Zealand grapefruit, tree tomatoes, and Chinese gooseberries. As many of these are not yet in full bearing, further increases over present production are expected. Total gross returns for fruit grown in the Kerikeri district in 1952 were about £91,000. Production figures shown for sweet oranges and standard lemons are poor

and would be classed as uneconomic. The figures of average yields are misleading for the following reasons: — At least half of the standard lemon trees are in neglected orchards; no worthwhile crop has been harvested from these trees for many years. Trees receiving good attention are yielding from 5 to 6 cases of fruit per year. . The position is somewhat similar with sweet oranges. A considerable number of orange trees have been planted recently and are not yet bearing. A proportion of the older trees are neglected and some of the varieties are unsuited to the district. The rootstock on which many of the older trees are budded has not induced constant cropping. Droughts experienced at intervals have also affected cropping and retarded the natural development of all fruit trees. Full Utilisation Since the average orchard size is only 5 acres, all ground must be fully utilised, if the unit is to be economic. To increase production many growers have filled small empty spaces with tree tomatoes and Chinese gooseberries. Tree tomatoes have also been planted along headlands on the sunny side of hakea shelter hedges. In some instances feijoa hedges have been planted along driveways and used as garden shelter.

The method adopted for the replacement of uneconomic citrus trees depends on individual circumstances. Growers with land available usually plant new areas; those with limited space interplant in the rows, of the bearing trees. Both methods aim to remove the unsatisfactory varieties when the new plantings come into worthwhile production. Closer planting distances are being adopted with new plantings, sufficient space being left for cultivation and spraying between rows of mature trees, but only sufficient space between trees for pruning and

picking.

Estimated Production of Kerikeri Orchards, 1948 to 1952

CITRUS* No. of Av. yield bearing trees per tree Fruit 1948 1949 1950 1951 1952 or vines or vine bus. bus. bus. bus. bus. bus. bus.f Sweet oranges .. 13,000 13,000 8,250 14,000 16,500 16,091 1 Lemons, Meyer .. 3,950 4,500 7,850 9,000 10,900 3,625 3 Lemons, standard 8,250 7,500 3,800 5,450 6,000 3,400 lg . N.Z. grapefruit .. 10,950 11,000 10,250 12,300 18,500 3,700 5 Wheeny grapefruit 250 1,650 1,800 2,350 1,400 400 34 Mandarins .. 50 .150 350 400 450 450. g . Total citrus .. 36,450 37,800 32,300 43,500 53,750 27,666 .— —■. SUB-TROPICAL tons tons tons tons tons Ib.f Tree tomatoes .. 5 .36 86 170 225 28,000 18 Passion fruit .. 14 10 12 32 18 6,000 6J ■ Chinese gooseberries .. —2 15 . 38 48 1,800 60 i Feijoas .. . . Icwt.. 1 2 4 5 625 18 i Total sub-tropical .19.05 .49 115 .244 296 36,425 ♦Production of citrus shown in the : equivalent of bushel cases. t Approximate.

Planting distances are regulated by the rootstock used and the vigour of individual varieties. Standard distances are: 15ft. x 12ft. for mandarins, 18ft. x 15ft. for oranges and Meyer lemons, and 20ft. x 18ft. for standard lemons and grapefruit.

The high prices received for the subtropical fruits such as tree tomatoes and Chinese gooseberries have made it possible for growers with small units to obtain worthwhile returns. It is realised, however, that 5 acres of orchard is fairly small under normal circumstances, but the adoption of closer citrus planting distances and the influence of the production of the other sub-tropical fruits have helped to solve this problem for the present.

Orchard Maintenance

Orchards at Kerikeri are now exceptionally well subdivided and protected by efficient shelter hedges. Sometimes subdivision by this means has been carried to extremes and has caused some crop loss.

When shelter hedges were first planted growers favoured the use of eucalypts and Pinus spp. These species established well, but proved to be unsuitable, except for high back shelter, since both species are serious soil robbers and compete vigorously with the fruiting plants for soil nutrients and moisture.

In recent years Hakea saligna has been planted almost exclusively and has proved to be superior to all other types. Hakea usually grows quickly to a height of about 18ft., and if kept well trimmed, can be grown within normal headland distances of fruiting plants without providing undue competition. Effective shelter is obtained with hakea planted along orchard boundaries and as hedges subdividing the orchard into acre or 2-acre blocks.

Cultivation

Most orchards are planted on sloping ground which has a shallow layer of open topsoil, and this can easily be lost by erosion unless care is taken with cultivation. For this reason, the general practice is to keep the surface cultivated throughout the dry summer only. Frequently an autumn cover crop is sown or the soil is permitted to produce volunteer weed growth, which is turned under in spring.

Some - growers have sown their orchards down to permanent pastures, using a grass and clover mixture to maintain a good sward the whole year. The results obtained with sod culture have not been promising. This is probably because of the competition for soil nutrients in spring and for moisture during the dry summer. Pasture and irrigation experiments are now in progress and it is hoped that more information on the possibilities of sod culture will be obtained from this work.

Discs or rotary cultivators are the main cultivating implements used in the area. The purchase of heavy equipment by individual growers is not warranted, because of the smallness of their holdings. The initial preparation

of new orchard areas and heavy cultivation on established orchards are carried out by contractors.

A deep digger or pan breaker is also extensively used to break the compact subsoil, especially before new blocks are planted. Single cuts are, however, sometimes made down the centre of tree rows in young established groves.

It has been found that root growth is restricted mainly to the zone of topsoil. To encourage deeper penetration some growers dig deep holes before planting and backfill with good topsoil and organic material.

After planting, the area immediately surrounding trees is kept clean by hand digging and hoeing.

Irrigation

Since the first orchards were planted the health of trees has been constantly threatened by summer droughts. Every mature tree in the district has been damaged at some time through lack of sufficient soil moisture. The dry spells have retarded tree development, upset blossoming and fruiting cycles, and caused serious reductions in crop yields in both the drought years and in' the following seasons.

To insure against drought damage many growers have installed some type of irrigation equipment. The amount of water readily obtainable is insufficient for the full irrigation of many orchards, because of the inadequate flow from local bores and the high cost of installing large pipes between rivers and streams and orchard properties.

The standard method for the distribution of water in the orchards is the overhead sprinkler. The amount of water applied per tree and per hour is dictated by the volume of water available and the capacity of the irrigation equipment installed.

Rivers in the district carry sufficient water even in drought periods to irrigate all the orchard areas, but most established orchards are too far from these rivers for direct irrigation. A major irrigation scheme is necessary to meet the requirements of the district. If growers could obtain sufficient water at a reasonable cost to safeguard against drought damage to the trees, one of the major handicaps of the district would be overcome and an increasing measure of stability brought to the fruit growing industry.

Cover Crops and Mulching

Blue lupins and oats are favoured as cover crops. Such crops are usually worked into the topsoil by rotary cultivators or cut and used for mulching under the trees. On other orchards the growth is mown, left to dry out, and eventually worked into the soil. Good spring and autumn weather ensures the growth of a considerable bulk of natural weed growth and growers often use this growth as a cover crop.

Supplies of green material are supplemented by material cut from paddocks owned by growers or neighbouring farmers who have surplus feed. Some growers go to considerable expense to obtain mulch material, damaged hay or stack bottoms in the surrounding districts being keenly sought.

Application of mulch around trees and plants helps to increase the humus content of the soil and conserve moisture in dry periods. Tree tomatoes and Chinese' gooseberries require a

cool, moist root run and appear to benefit greatly from the regular application of mulch material. The growing of suitable legumes, such as clover and lucerne, as an extra source of nitrogen for the fruit trees has been attempted, but results to date have not been favourable. Manuring- _ 8 ~, ~ . i xx t Because of the thin layer of topsoil, h ea Y y , applications of manure are needed to build up and maintain fertility In earlier years many growers placed great importance on the exelusive use of organic materials. Compost was made from all available plant and animal residues and supplemented with suitable organic manure such as blood and bone. The Kerikeri soils are naturally highly acid and deficient in phosphate, and heavy applications of lime are often necessary to correct this acidity, Applications of phosphatic fertilisers then follow. Growth responses which often follow the application of any quick-acting form of nitrogen indicate that supplies of this element are likely to be low. The addition of potash may also improve fruit quality and texture even though a major deficiency does not exist. In a soil of this type it is unlikely that optimum nutrient levels can be reached and maintained solely by applying organic matter. The present tendency among growers is to apply regular dressings of a suitably balanced fertiliser mixture. This may be supplemented by special applications of quick-acting nitrogenous fertilisers,

The total quantity of manure applied annually varies with the age of trees and local soil conditions. The standard rate of application is lib. of a balanced mixture for each year of the tree’s age from planting. Despite present high costs of manures . the rate of

application is fully justified by profitable increases in production. If manuring is neglected, even for one season, tree growth and health may be seriously affected. Pruning Pruning of citrus is often neglected and even the importance of pruning young trees to guide formation of the main framework is overlooked by many. Most growers inspect their trees regularly for . signs of borer damage, and when the infested branches are being pr uned or treated other wood which is dead or diseased is cut away and congested growth thinned out. Many, lemon growers make a practice o f shortening back fruiting laterals during : picking operations. Where lemon trees have grown very tall, making picking and spraying difficult and costly, the tall centre branches are pruned well back to bring the trees to a satisfactory height. Severe pruning to rejuvenate old, neglected citrus trees has been successful only when coupled with good cultural attention. The pruning of tree tomato trees is now an accepted district practice. The entire head of old unthrifty trees is removed. Younger trees are pruned back in spring, cuts being made immediately above suitable new growth shoots in the head of the tree. By this method all spent fruiting wood is removed and new growth encouraged, Trees headed back severely produce late crops, which extend the harvesting season. If some are so treated each year, the longer harvesting season should be beneficial in reducing labour

costs. The susceptibility of unpruned passion fruit vines to common diseases such as brown spot and grease spot has shown growers that they must prune their vines heavily if clean crops are to be obtained.

The exceptionally vigorous growth of Chinese gooseberries tends to make their pruning a major seasonal operation. The standard practice is to prune away as much old, spent wood as possible and then to space out new wood shoots, leaving the strongest to carry the next season’s fruit. Severe pruning coupled with good cultural practices keeps plants growing strongly and ensures maximum cropping. Pest and Disease Control The mild climate of the district favours the development and spread of some diseases and pests, though incidence of disease is not unduly high. Most growers depend on contractors using high-powered machines to do their spraying. This practice, which is adopted because many of the orchards are small and the capital cost of spraying equipment is high, does not always lend itself to efficient disease control. Contractors covering several properties may be delayed by weather and an important spray period may be missed. To reduce costs growers without their own spraying equipment also tend to reduce the number of spray applications below the number necessary for good disease control. Some orchardists unfortunately are not “spray conscious” and their failure to spray regularly results in the production of . a higher percentage of lowgrade fruit than is desirable or necessary. . Tree health is also adversely affected.

Diseases and pests which are common on citrus in the district are: Citrus verrucosis (Elsinoe fawcetti) , melanose (Phomopsis citri), citrus brown rot (Phytop citrophthora), bark blotch (Ascochyta corticola), wither tip (Glomerella cingulata), citrus blast (Pseudomonas syringae) , sooty mould (Capnodium citricolum) , black aphis (Aphis citricidus), citrus borer (Aemona hirta), dicky rice weevil (Maleuterpes spinipes) , leaf-roller caterpillar (Tortrix sp.), red mite (Paratetranychus citri), thrips (several species), and scale insects (several species). Brown spot (Alternaria passiflprae) and grease spot (Phytomonas passiflorae) are the principal diseases and the passion vine hopper (Scolypopa australis) the main pest affecting passion fruit. Powdery mildew (Oidium sp.) and the green vegetable bug (Nezara viridula) can be troublesome on tree tomatoes unless controlled. Harvesting and Handling Crop Nearly all orchard plantings include citrus and other sub-tropical fruit varieties with the result that harvesting is spread over all seasons of the year. Harvesting in most orchards is done by the owner, often with the assistance of his family. Some combine with neighbouring growers for harvesting. On the larger orchards casual labour from local sources is employed during rush periods.

The Marketing Department has a. depot at Kerikeri which handles all the standard lemon crop. The depot also packs for growers a quantity of other citrus. The balance of the citrus and. all the sub-tropical fruit crop is packed, and sent to markets direct from, orchards. A satisfactory standard ismaintained with the grading and packing of most of this fruit, although there is room for improvement in some instances. Care is taken by some growers to maintain very high grading and packing standards; such attention to detail results in higher averageprices.

The marketing of the crop with the' exception of standard lemons is thegrowers’ responsibility. Fruit from Kerikeri is sent to every market floor in New Zealand and the success of’ the year’s operations is often strongly influenced by the ability of growers, to forecast market trends and so to consign their fruit to the best markets. A proportion of the crop is sold direct to private buyers. One of the handicaps which Kerikeri growers have to face is that of distance from their principal markets, which considerably increases the cost of marketing.

Future of Industry

The general development of thefruit industry at Kerikeri has not been one of easy success. The early growers were chiefly retired people' who treated fruit growing as an interesting hobby, whereas the management of a modern orchard is a fulltime occupation for a physically fit person. Unsuitable varieties, inadequate attention, and droughts have all caused setbacks from time to time and the industry is only now finding its feet.

Given _ adequate moisture and fertiliser citrus and sub-tropical fruits grow and crop well in the district. Tree tomatoes, Chinese gooseberries,. Meyer lemons, and New Zealand grapefruit have all proved satisfactory. New stocks and varieties of mandarins and sweet oranges may open the door for expansion in these lines.

Quite a large number of orchards have changed hands during recent years and most of the new growers are young people who depend on their orchard returns for their livelihood. They have the incentive and determination to succeed and their advent has given an added fillip to the industry.

There is still land not yet planted which is suitable for growing citrus and sub-tropicals. Any expansion in the industry will depend upon such factors as availability of suitable land, water supply, the use of suitable kinds and varieties of fruit, adequate manuring, and hard work.

To those of the early growers who have remained to make a success of their holdings credit is due for the manner in which they faced up to and overcame the various difficulties and setbacks experienced during the years. The experience thus gained should be of help to the newer growers in their endeavours to become established and to extend a valuable industry.

Aid to Steam Sterilisation of Glasshouses

STEAM sterilisation of glasshouses is always a hot job, especially when it is done in late summer. A fan devised by a Blenheim grower makes the atmosphere more comfortable for operations, first by maintaining a constant circulation of fresh air in the glasshouse and second by blowing escaped steam away from the workmen.

The illustration below shows the general construction of the fan, and details of the apparatus are: —

Fan: Four blades; diameter of 15in; 3in. pitch on blades.

Motor: J h.p.; 1450 r.p.m. Framework: 3ft. 6in. high; bracing timber so arranged that flow of air is unobstructed.

The fan should be 20 to 25ft. from the workmen. If it is closer, too much draught is created, and much of the effect is lost if the fan is too far away. The apparatus has not been tried in a glasshouse where chloropicrin is being used, but it is probable that the fan would be of great benefit in removing any fumes from the vicinity of the operators. Acknowledgment Acknowledgment is made to Mr. A. M. Le Poidevin, Holdaway Street, Blenheim, for supplying details of this fan. —D. W. McCALLUM, Horticultural Instructor, Department of Agriculture, Blenheim