CITRUS FRUITGROWING IN NEW ZEALAND.

New Zealand Journal of Agriculture, Volume XXXIX, Issue 1, 20 July 1929, Page 48

CITRUS FRUITGROWING IN NEW ZEALAND.

Lecturette by

P. EVERETT,

Orchard . Instructor, Thames and Bay of Plenty

district, broadcast from Radio Station 2YA, Wellington, July, 1929

It should first be explained that the name citrus is a generic name for ' a number of plants, and includes lemons, oranges, limes, citrons, grapefruits, mandarins, and shaddocks. All these fruits are to be found growing in New Zealand to a greater or lesser extent. Most of the citrus family are natives of India and other warm parts of Asia; consequently the colder parts of this country are not generally suitable for their growth. The best localities for their culture are in the east coast region of the Auckland ' Province. In the year 1928 the area in orange and lemon trees in Auckland was 875 acres, as compared with 160 acres for all other parts of New Zealand combined. •During the four-year period from 1924 to 1928 the area ,in these fruits increased by 139 acres in the Auckland Province, whereas the increase for all other districts was only 12 acres.

Regarding the quantity of these fruits produced in New Zealand, it is estimated that during the year ended 31st March last the production for the Tauranga district alone was approximately 15,000 bushel cases of lemons and 1,500 bushel cases of oranges. When it is borne in mind that there are comparatively few citrusorchards in New Zealand yet in full bearing, and that probably more than one-half of the orchards have not yet commenced to bear fruit, it will be seen that this young industry already counts for something. Further, the increased area being planted annually goes to show that considerable progress is being made in the culture of these fruits.

Persons contemplating the planting of citrus fruit-trees for commercial purposes , would be well advised to go very thoroughly into the matter of suitable varieties and stocks, for varieties that have - proved suitable for commercial planting 'in some parts may not give satisfaction 'in other parts. Information on these matters can always be obtained from the district Orchard Instructor, or from the Director of the Horticulture Division, Department of Agriculture, Wellington.

For those wishing to grow a few trees for domestic purposes I would suggest the following varieties as being suitable :

Lemons: Lisbon, Genoa, and Eureka. For the colder parts of New Zealand the Meyer lemon is claimed to be most suitable, but it is not generally recommended for commercial planting at the present time. ,

Oranges : Ruby, Washington Navel, and Navalencia. For marmalade the Poorman orange is the best. There are probably more Poorman orange-trees grown in New Zealand than all other varieties together, and their fruit is rapidly coming into favour for dessert use.

Other citrus fruits, such as grapefruits, limes, mandarins, citrons, and shaddocks, will all thrive well in warm and sheltered locations in the North Island, and bear good crops of fruit. Citrus-trees, being

evergreen, are often grown on lawns for ornamental purposes. For fruit-production, however, it is most important that they be planted in well-drained soil and in a sheltered location. .

Brief reference will now be made to the diseases and insect pests that are troublesome in citrus orchards. Citrus-trees do not require nearly the same amount of attention as do most other fruittrees. For instance, apple-trees are often sprayed as many as nine times a year, whereas citrus-trees seldom require more than three sprayings annually, and in many orchards one spraying. is all that is necessary. The three most serious troubles citrus-growers in New Zealand have to contend with in their orchards are citrus brown-rot, red scale, and verrucosis. . In many orchards that have been well cared for from the time of planting neither red scale nor verrucosis has yet made its appearance.

Brown-rot has been present in parts of Auckland Province for many years, but was not general throughout citrus orchards in this district until the winter of 1927. During that winter extensive damage was done in a great many orchards, not through the disease being difficult to control but because growers were caught unprepared. ’ In most parts of New Zealand all that is necessary to keep citrus-trees free from brown-rot is to spray before the disease makes its appearance each winter with bordeaux mixture, at a strength of 4-4-40. In certain clay soils it has been found necessary to supplement this treatment by applying sulphate of iron to the soil under the trees, and by cutting away all limbs growing near the ground.

Verrucosis, which causes grey-coloured scabs and protuberances on lemons, can be kept in control by applying one bordeaux spray annually during the month of November. Where trees are severely infected, three sprayings should be applied each year until the disease is got under control.

■ Red scale is more difficult to control than either of the other two diseases mentioned. To combat this insect spraying-oil should be applied. Reasonable control can be effected by spraying once annually, the most effective time. being either the last week in February or the first week in March, according to the seasonal conditions. To make certain that every portion of the tree is coated with the spray it is necessary to first see that the tree is reasonably open. In cases of severe infestation two sprayings annually are advisable, the first early in February and the second towards the end of March. This treatment suggested for the control of red scale is equally effective for other scale insects and citrus red-mite that are at times troublesome on citrus-trees.

Now for a few remarks to consumers of citrus fruits, which includes almost everybody. For many years past there has been a certain amount of prejudice against lemons and oranges grown in our own country, brought about by the false impression that the locally grown fruit was invariably inferior to the imported article, and that the keeping-quality was also inferior. This prejudice happily is now disappearing as a result of the more up-to-date methods of handling the fruit now being practised by our growers.

It is held that for all ordinary uses the first-grade locally grown lemons are equal in quality to the best imported lemons. Regarding oranges grown in New Zealand, in many cases this fruit is not equal to the imported: article that has been grown in a warmer climate. However, varieties suitable to our climate, and grown under favourable conditions, will produce fruit that leaves little to be desired.

The main reason why the prejudice referred to has existed may be said to be that until very recent years most of our lemon-growers marketed their fruit individually, practised crude methods in handling their crop, and adopted no measures for the prevention of decay. For instance, lemons were very often forcibly pulled off the trees, and this frequently damaged the base of the fruit. In other cases the fruit was allowed to drop on to hard ground and become bruised. It was then gathered and roughly tipped into cases, and straightway despatched to market. Again,' the trees were stripped of all coloured fruit about every third month, which resulted in many lemons , being oversize and having a thick rind. Lemons handled in a rough manner can seldom be kept long , before decay sets in, and when the fruits are lying packed in cases the rot rapidly spreads from one to another, so that in a few weeks a large proportion in the case will have been destroyed.

The present-day methods of treatment of lemons in New Zealand show much improvement compared with those prevailing a few years ago. Picking of the fruit is now done monthly so that oversized fruits will be avoided, for, no matter how green in appearance a lemon may be, if it has attained the most desirable size it is ready for picking. The minimum size for picking is usually 2-j in. diameter. Experienced pickers can tell at a glance the size of the fruit; pickers of less experience usually carry a ring with a diameter of 2| in. for measuring fruits of doubtful size. The fruit is severed from the tree, by small secateurs designed for that purpose, and carefully placed in picking-bags.. From the picking-bags the fruit is removed, one by one, into the orchard case, and then conveyed to the curing and packing depot. On arrival at the depot the fruit is graded. The yellow lemons are also separated from the green lemons. All of the better-grade fruit is placed in single-layer trays and stored in a curing room specially constructed for the purpose, light being eliminated -as much as possible and a moderate even temperature maintained.

These trays of lemons are looked over periodically, and any fruits showing signs of decay are removed. When the fruit has become thoroughly cured it is removed to the packing-room, where it is washed. When dried it is graded to size, for fruit with a difference of more than J in. in diameter should not be packed in any one case. Every first-grade fruit is wrapped in tissue-paper, and packing is done systematically in new cases. The cases are wired at each end, so as to prevent breakage if roughly handled during transit to market.

Lemons treated in this way can be relied upon to keep at least three months after being put on the market without excessive wilting, and with a smaller percentage of decay than is general with much of the imported fruit. The chief advantages of a

properly cured lemon over an uncured one are that in the process of curing the thickness of the rind is reduced by about 50 per cent, without giving the fruit a wilted appearance and without reducing the juice content.

As regards New-Zealand-grown oranges, their former unpopularity has been principally due to the fact that until recently a large proportion of the fruit offered for sale was from seedling trees which produced a poor type of fruit. However, there is now a considerable area in Auckland Province planted with the best varieties. Many of these trees are now coming into bearing, and each year more of their goodquality fruit is being sold on the local markets. In New Zealand there are two co-operative curing and packing depots for the handling and marketing of citrus fruits, one being at Tauranga and the other in Auckland. The - depot at Tauranga is handling approximately 90 per cent, of the lemons grown in the Bay of Plenty, while the Auckland establishment handles a considerable quantity of citrus fruits grown in the vicinity of Auckland City and at Whangarei. These co-operative organizations have done valuable work in standardizing grades and in preventing the marketing of uncured and poor-quality lemons. Lower-grade but suitable fruit from these depots is sold to 'factories for use in connection with the manufacture of lemon juice and peel.