Cultivation of the Chinese Gooseberry

New Zealand Journal of Agriculture, Volume 68, Issue 2, 15 February 1944, Page 111

Cultivation of the Chinese Gooseberry

The Chinese gooseberry, the fruit of a vine imported from China, is gaining increasing popularity in New Zealand, where, in most parts of the North Island, except the high country, the climatic conditions for its growth are satisfactory. In the South Island, too, the conditions are suitable in localities where damaging spring frosts do not occur. Although the plant can withstand heavy frosts in winter, it may suffer considerable harm from frosts in the growing season.

F. SYDENHAM,

Assistant Horticulturist, Wellington. (On Active Service)

technically as Actinidia KNOWN technically as gooseberry chinensis, the Chinese gooseberry occurs naturally as a deciduous fruiting vine growing to the height of 30 feet or more on the forest margins in -China. It . is a vigorous twining vine, and when cultivated on fertile land and given sufficient space, will assume large .proportions if not "controlled. The plants are dioecious, i.e., the sexes are present on different plants. Not- only is it essential to have plants of each sex, but they must flower- at the same time. One male plant is generally sufficient for 5-10 female plants. The number depends on the method of planting which is described below. Strain As with most fruits, strain is of great importance. There is a considerable variation in type,. as Fig. 2 shows. Strains are available which are definitely of inferior size. In shape, some are round, and some oval or elongated, while others have flat ends. Certain strains contain a fibrous core, and . a few possess a hard, woody centre-piece, ■ which is very sharp and resembles a toothpick or a fish bone. The colour of the flesh is generally an attractive shade of translucent green; . but there are strains that are very pale, almost white in colour. The fruit, which matures. during the winter months, is increasing in popularity; ■but any further planting for commercial purposes should be of the large oval, or elongated, green-fleshed type,

with an entire absence of internal fibrous or woody material. ' Climate The plant is a native of China, and will stand quite heavy winter 'frosts; but frosts occurring during the growing season do a considerable amount of injury. If damaging frosts should occur when the new . growth is v put out, this growth is checked, and the small flower buds are destroyed. Unseasonable frosts occurring during the blossoming period (end of October and early November) reduce or prevent the setting of the' fruit. Climatic conditions are quite satisfactory in most parts of the North Island, an exception being the higher country. In the South' Island, satisfactory production is obtainable where damaging spring frosts do not occur. Winter frosts in the localities where the plant can be grown do -not appear to injure the fruit hanging on the vine. In such a'position the fruit itself will stand 6 to 8 degrees.of frost, ■ and - possibly more without harm. The flavour is. definitely improved after frosts occur. The -large leaves are not suited to wintry conditions. ; As a consequence, reasonable shelter is required. . The most. . suitable soil is a wellcultivated, deep, fertile loam, which is drained, but. which retains the moisture during the summer. Wet soils must be avoided. Propagation The Chinese gooseberry grows readily from seed, but this method of

propagation is not recommended. Ton great a proportion of male plants is produced, and the variation in strain of the female plants produced is undesirable in a • commercial production. - Grafting is the most satisfactory means, and the root graft method usually employed is not difficult even for amateurs. Sections of stock and scion of similar diameter should be united. The female scions should be taken from a plant of the desired strain, and, if possible, worked into a piece of root of a female, plant. The reason for the use of the female root is that if .‘the graft failed, and the root developed growth, a female plant would result. The use of seedlings as stocks is not recommended, as they are very liable to break into growth below the union, when both male and female branches might occur on the same plant. This occurs frequently where the. budding method of propagation. is employed. When grafting, a long , union is preferred. This is tied with raffia and planted so that the union is covered with soil. Male and female plants should be kept separate. To avoid mistakes it is a wise plan to employ two different types ,of grafting. The tongue or whip graft (like placing two fingers, together) may be used with female plants, and the cleft graft (like placing one finger between two others) for the male plants. These two types of graft are distinguishable for several years.

Planting ■ ■ / When grown as a commercial crop the plants should be planted close to strong fences, 4 ft. 6 in. to 5 ft. high, with posts 15-to 20 ft. apart (according to the planting distances). Three wires, the lowest 18 in. from the 1 ground and the others evenly spaced, should be used. Heavy wire is necessary, and No. 6 gauge is prefergable; to No. 8. The, fences, which should run approximately north and south in order to obtain the maximum amount of light on both sides, should be spaced to permit efficient inter-cul-tivation and to allow room for handling the fruit during harvest. Ten feet is a suitable distance. With fences higher than 5 ft. it is difficult to attend to the suppression of shoots during the summer, whereas with the pergola type of structure this summer pruning is impossible, and the dense shade provided by the top growth causes the death of much of the valuable lower wood. The growing of Chinese gooseberries on a tall fence and pergola, or over a shed, has nothing to recommend it. It leads to the ultimate production of . inferiorsized fruit at a height where ,it. is difficult to harvest. Spacing of Plants The plants should be spaced 12 to 20 ft. apart in the rows. Place 1 the plants between the posts so that ' in subsequent years the posts will support the heavy weight of fruit on the extremities of the vines. The main branches will assist in supporting the fruit of the centre portion of the vine. As male and female plants are required, and one . male is sufficient for

5 to 10 females, the male ( plants should be arranged in .the order that will afford the most efficient pollination,, and at the same time make for the easiest and most efficient management of the plantation. It is the usual practice to space the male. plants as evenly ■ as . possible < over the whole area so that they are approximately the same distance apart, and so that they are surrounded by female plants. An improvement on. this method is the planting of male plants separately in rows throughout the plantation. As the male plants do not produce fruit, they do not require the same pruning and attention as the : bearing plants. One row of male plants to five rows of females would be quite sufficient. In the male row, planting at double the spacing within the'row, i.e., 30 to 40 ft. apart, would furnish the fence completely, and no female plants would be more than 30 ft. from male wood. At' these planting distances, males 30 to 40 ft.,* and females 15 to 20 ft., 1 male is required for 10 females. Wind Break Where Chinese gooseberries are grown in an unsheltered - position, rows of male plants may surround the plantation, and serve as , a wind break. They ; might be allowed to grow .to considerable size, being reduced, when necessary, by means of a slasher. In smaller plantings it is satisfactory to plant only female plants, and to graft a male branch low down on the 4th or sth female plants. This branch should then be trained on the bottom wire, say 18 in. to 2 "ft. from the ground, and pruned so that it does not outgrow the female plant.

These male branches should be identified so that they may be treated separately at pruning time, and may be allowed to. extend- as far as possible along the fence. ' ■■ - .- 1 • ?. ’. ' ’ '. ■■■ After Planting Good plants firmly planted in fertile soil put out new leaders in the early summer, and so that these may be trained properly the fence should be erected before, or immediately after, planting. It .is. of great importance to furnish the fence from the bottom upwards, ■ the first pair of leaders produced being trained' to .the lowest wire (18-in., to 2 ft. from the ground) on either side of the plant, and the second pair in a similar manner to the second wire (3 ft. 6 in. from the ground). . It should be sufficient to furnish the two lower wires in the first year, and if the tips of side branches are removed as they become about 12 in. long, the energy of the plant in the first year will be devoted to furnishing r the lower 1 wires. If the plants do well these leaders make 7 to 10 feet of growth, and those of adjacent plants' will meet. In the second year, there will be little difficulty in furnishing the third and *top wire. During the second year, much lateral growth will develop from the previous l year’s wood. This should be cut back to about 12 in', and subsequent shoots also . shortened. Pruning and Training To furnish a fence properly requires, close attention in the early years, the benefits of which will be appreciated in later years when the plants come into bearing. During the second and third years, constant attention to pruning and training is required, as the available sap-supply' is used for growth. When, however, the female vines are in heavy bearing, so much of the sap is required in developing the fruit that only a little growth is put out. - On the low fence it is not difficult to keep this in check.. With the male plant the position is different. As no fruit is produced all the sap goes into growth, which requires a considerable' reduction, especially in the winter. The wisdom of planting the male plants separately will be apparent. In such a position an occasional summer pruning may be given. When the plants are grown together on a common stock, both male and female plants should receive the same attention. - . Mature Plants Both summer ' and winter pruning is necessary, and in many ways the Chinese gooseberry resembles the grape-vine. In the spring, growth is put out from dormant buds, and on this new growth the fruit develops. Where vigorous growth is put out, it

is advisable to stop it several leaves beyond the ' last fruit. Where less ■ vigorous growth is made, there is no need for such stopping back. All vigorous, * non-fruiting growth made during the growing season should be cut back or removed entirely where it is not required to form fruiting wood or leaders: By this means, the shading of the lower branches, and the consequent death of many laterals, is avoided. During the winter, the fruiting wood generally requires a consider- . able amount of thinning out. It is not cut back, as are grapes, to rods, but should be thinned out in much the same way as the ' spur and lateral wood of apple trees. - Better Fruit This results in the production of fewer, but larger fruits. There .is a demand for quality fruit, and this can be obtained only where the. plants are controlled. On plants which are allowed to grow unchecked, fruit. of' good size will be produced for a few years, but as the size of • the plant increases and the fruit develops at a distance from the sap supply, the fruit will become smaller. Fig. 4 gives a comparison ; of the types of fruit produced by pruned and unpruned vines of the same strain. The larger specimens, averaging seven to the pound, were selected from controlled vines, whereas the smaller, specimens were a fair sample from an uncontrolled plantation. A great proportion of fruit weighing 7 ..to 10 to the pound is not difficult to obtain under the system of pruning described. Note: The winter pruning- should be done in July after harvesting the crop, and when the plant is dormant. If it is left till late winter or early spring, sap exudes from the cuts made, and may cause a considerable loss of valuable wood through its dying back.

Manuring Mature plants, to obtain high production, will require 'fairly heavy manuring. About 6 lb. of blood and bone per plant (1 ton per acre) in .the late winter, and 1 lb. sulphate of ammonia or dried blood per plant (3 cwt. per acre) at .flowering time should give satisfactory results. These amounts should be used when the plants are in heavy bearing. A cover crop sown with a light dusting of super in the autumn does not interfere seriously with picking,' and may be worked under early in the spring. z If young plants are used, and they make good growth, it is possible that a few fruits will develop in the second ■ year on the two lower branches. In the third year, the production will be greater. Heavy yields are obtained from the fourth year onwards. The profitable life of . the vine is not known, but it is likely to be at least 20 years. As the crop is not grown extensively and few records are kept, a figure for production is not easy to obtain. The produce of one plant in its fifth year aVTauranga weighed 200 lb.’ . ; ’ Harvesting The vines bloom early in November. The. fruit develops rapidly, and' growth is completed about the middle of May. During the month of June, the fruit is quite firm and high in pectin, at which. stage it is useful for preserving. Early in July, it begins to ripen, when - much of its pectin content .is lost. It then becomes a dessert fruit. It is necessary to pick the crop early in July, as it is readily taken by small birds if allowed to ripen, on the vines. It . is best picked after being frosted and after all the leaves have fallen. After picking, the fruit may be stored in , a cool, draught-proof store

(to prevent withering) and marketed before it becomes soft. It should be possible to keep a quantity of it till August or September, when better prices will be obtained on the market. The fruit should be ..graded and packed in 20 lb. boxes. '• There are no records of any specific disease attacking the Chinese gooseberry in New Zealand.