Kiwi (lat. Actinidia deliciosa) is a perennial deciduous plant from the Actinidiaceae family. It spread around the world from China, from where it first arrived in New Zealand at the beginning of the 20th century. It was only in the middle of the 20th century that it began to be cultivated for the needs of the world market (Italy, Chile, Greece, France, Japan, the United States of America).
It is classified as a southern or subtropical fruit, such as pineapple, avocado, banana, date, guava, coconut, mango, passion fruit, papaya, pomegranate.
Kiwi looks like a vine. The plant is a climber, very strong and woody. Although dark green kiwi leaves are most often seen, the appearance of the leaves depends on the variety and can be wide, elongated, heart-shaped or oval. Since kiwi is a dioecious plant, it contains both female and male flowers on separate plants. The flowers are white and 4 to 5 cm in size.
As for the fruits, they are oval and up to 8 cm long. Kiwi is recognized by its characteristic brown skin with tiny hairs, and the inside of the fruit stands out for its green color and tiny black seeds.
In our areas, kiwi is grown on the coast in places that provide good conditions for cultivation.
Kiwi varieties
Kiwi can be said to be a relatively new fruit because it only became known to the wider world in the middle of the 20th century. In recent times, the significance and cultivation of certain varieties of kiwi has been discussed. Kiwi varieties, looking from the perspective of importance, can be divided into production and perspective varieties. Since kiwi is a dioecious fruit, both female and male varieties can be distinguished. Male varieties are pollinators of female varieties with functional flowers.
Female varieties: Hayward, Bruno, Monty, Abbott, Elison, Elmwood, Top-Star, Elizabeth = AC226, Hayward clone K., Katiuscia
Male varieties: Tomuri, Matua, M-3, P1, Autari
Female varieties
Kiwi is a unisexual plant and it is necessary to plant it in pairs, that is, to plant male and female seedlings together. The female seedling leaves its functional flowers for pollination.
Hayward
The Hayward variety can be said to be the most famous variety of kiwi, and it has been on the market since 1930. It is successfully grown in New Zealand, Italy, Japan, France, California and Montenegro. The harvest of this variety takes place at the beginning of November. Fruits can be stored for 5 to 6 months in a refrigerator, at a temperature of 0 to 1ºC and with air humidity of 90 to 95%. It looks like a tree of medium vigor and begins to bear fruit in the fourth year, and the leaf is round. The cream and white flowers are usually solitary, and flowering begins in late May and lasts approximately 11 days. A good combination for pollination is the Hayward and Tomori varieties. Although the fruits are large (100 g), they are equal in size and elliptically ovoid. They are brown in color and covered with hairs. The meat is greenish in color and has a sweet-sour taste and melts in your mouth. The Hayward variety is sensitive to drought and low humidity. The fruits fetch a very high price on the market.
Bruno
The variety was found in New Zealand in 1920, and has been in production since 1930. It is grown in New Zealand, Italy, France and California. It is harvested at the beginning of November and keeps well in the refrigerator. In appearance, the tree is extremely lush and very fertile. This variety is moderately sensitive to drought and pests. The flowers are single or in pairs, also cream or white. It blooms at the end of May, and the flowering lasts slightly shorter than the Hayward variety, approximately 9 days. The fruits are medium-sized (from 70 to 80 g), uniform and cylindrically elongated. The skin is dark brown and covered with thick hairs. The meat is transparent green, moderately juicy and aromatic and sweet and sour.
Monty
The Monty variety has been known since 1950 in New Zealand and in Italy and France. It is harvested at the beginning of November and stored in the refrigerator for up to two months. In appearance, the tree is also extremely lush and very fertile. It is resistant to drought and pests. Compared to flowers that are cream and white in color, there are usually 4 to 6 flowers per bloom. This variety blooms at the end of May, and the flowering lasts approximately 10 days. The leaf is round, and the fruits are small (from 40 to 50 g) and of uneven shape – from slightly pear-shaped to oval. The skin is brown and covered with thick hairs. The meat is transparent green, juicy, sweet and slightly fragrant. The fruits are suitable for industrial processing. Monty is a very native variety. In order to obtain larger fruits, proper pruning and thinning of the fruits is necessary.
Abbott
The Abbott variety also originates from New Zealand, and is also grown in Italy and France. It is harvested at the end of October and the beginning of November. The fruits are of medium size and are stored in the refrigerator. The tree looks lush and native. It starts bearing fruit in the third or fourth year after planting. The variety is sensitive to drought, wind and pests. The cream and white flowers are single or 2-3 in bloom. It begins to bloom medium early, approximately at the end of the second half of May, and flowering lasts 10 days. The fruits are medium-sized (from 70 to 80 g). The skin is brown and covered with thick hairs. The meat is transparent green, moderately juicy, slightly fragrant and not excessively sour.
Allison
The Allison variety was discovered in New Zealand in 1920, and has been in production since 1930. The tree looks lush and native. This variety begins to bear fruit 3-4 years after planting. The variety is sensitive to drought and pests. Flowers mostly occur in pairs. It blooms earlier than the Abbott variety, in mid-May. The fruits are very similar to the Abbott variety.
Elmwood
The Elmwood variety was discovered in New Zealand. It is extremely lush and fruitful, and the flowers are single. It blooms at the end of May and produces extremely large (from 160 to 180 g) and uniform fruits. Her flesh is bright green in color. It is usually harvested at the beginning of November, and can be stored in the refrigerator for up to three months. It is sensitive to drought.
Top-Star
Unlike the varieties presented so far, the Top-Star variety was discovered in Italy in 1985, and is actually a mutant of the Hayward variety. It is not too lush, but it is very fertile. The cream and white flowers are single, and blooms at the end of May. It shares this similarity with the Hayward variety, as well as the fact that it is pollinated by the same pollinator, i.e. the Tomori variety. This variety produces very large fruits (150 g) that are uniform in size and round. The skin is hairless, and the meat is bright green in color and has an excellent sweet and sour taste. Top-Star is harvested in the first half of November, and the fruits can be stored in the refrigerator for up to 6 months.
Elizabeth = AC226
This is a lush and very fertile variety, like the previous mutant variety Hayward. Its cream and white flowers are also single, and it blooms 4 to 5 days before the Hayward variety. This variety is pollinated by the Matua variety. It produces very large fruits (130 g to 160 g). The skin is red-brown to greyish. The flesh is not green, but yellow to yellow-orange with a sweet to sweet-sour taste. It is harvested very early, in late September or early October. The fruits can be stored in the refrigerator for 2 to 3 months.
Hayward clone K
It is another mutant of the Hayward variety from Italy, therefore the flowers of this variety are single and cream to white in color, and the tree is medium lush. It also blooms at the same time as the Hayward variety, i.e. at the end of May. It starts bearing fruit in the third or fourth year after planting. Harvesting is done at the end of October. The pollinator for this variety is variety P1, after which an extremely large fruit (120 g to 140 g) is produced, which is elongated and oval. The flesh is greenish in color and sweet and sour.
Katiuscia
Katiuscia originates from Italy back in 1992. Her so-called parents are varieties Hayward and AD 117. This variety is moderately lush, and the flowers are single. It produces extremely large fruits (160 g to 180 g) that are spherical in shape. The meat is greenish, melting and tasty. The harvest is done at the end of October, and the pollinator is the P1 variety.
Male varieties
On average, one male should be planted for every eight female varieties, which will be in charge of pollination. So, the male variety will not bear fruit, but will perform the important role of pollination and the perhaps less important one – it will decorate the garden. The most famous functional male varieties of kiwi are Tomuri and Matua.
Tomuri
Tomuri hails from New Zealand. This variety is adorned with stamen (male) flowers on a lush tree that come in bunches, usually 5 flowers in one bunch. Tomuri blooms profusely and for a long time, approximately 10-12 days. It starts flowering 3-4 days before the Hayward variety and ends two days later. Tomuri stands out as the best pollinator for the most famous female variety Hayward.
Mother
Matua also originates from New Zealand. This variety is usually adorned with 3 stamen (male) flowers on a lush tree. Flowering starts a little earlier than in the Tomori variety and lasts longer. It is suitable as a pollinator for the earlier blooming Abbot, Allison and Elizabeth varieties.
M-3
This variety was discovered as a pollinator in Italy. It is known to bloom profusely, starting to bloom 3-4 days before the Hayward variety and ending a few days later.
P1
This variety also comes from Italy. It blooms profusely and approximately 2-3 days later than the Hayward variety. It successfully pollinates Hayward clone K and Katiuscia varieties.
Authors
The variety was created in Italy, and the so-called her parents are Hayward and M-3. Blooms at the same time as the Hayward variety.
Kiwi planting
Before planting kiwi, it is necessary to educate yourself about the time of planting, the type and type of soil this plant requires and at what temperatures it thrives. Also, it is necessary to keep in mind the use of light energy, which depends on the arrangement of fruit trees and cultivation forms. Particular attention should be paid to determining the method of cultivation, as well as to the distance between plants, because light is crucial during the period of flowering and pollination.
Planting time
The usual time to plant kiwi is winter or early spring. Before that, it is necessary to prepare the field during the summer or in the autumn of the previous year, and the actual fertilization and deep plowing should be done before planting.
Choosing the substrate for planting
In our areas, you will most often find kiwi, which is the result of propagation of green and, above all, mature cuttings. In addition, in production it is possible to find kiwi obtained by grafting on seed. Although the first variant is more common in our areas, in some countries production by grafting is recognized as more important. Production by grafting implies a substrate in the form of seeds of cultural varieties of kiwi. In our case, it is most often a seed of the Bruno variety. When planting, it is possible to use any seedling as far as the method of production is concerned, the only thing that matters in the end is its quality.
Planting seedlings
Before planting kiwi plantations, rows and planting sites should be staked and planting holes should be dug, which should be deep and wide so that seedlings and a certain amount of manure can be placed in them without difficulty.
The term double pergola or T-system refers to the growing form commonly used in kiwifruit plantations. Before shaping the cultivation form, reinforcement of T-posts and three rows of galvanized wire should be provided. After it is planted, the seedling is shortened to two buds, which will be the basis for the emergence of two saplings at the beginning of the growing season. The upper one will be straightened with a reed, and the second one will be shortened to a height of 20-30 cm. Such a shortened sapling will serve as a reserve for the main sapling, that is, it will be its reserve. When we are sure that there is no longer any danger of the main sapling breaking, the spare sapling can be removed. The pergola is formed at a height of 190-200 cm, and the main sapling should be grown up to that height. If everything is done correctly, in the first year you will get a straight and strong sapling of the same height. This cultivation system requires planting plantations at a distance of 3.5 to 4.5 m between the rows and 5 per row.
Ground
When planting kiwi, good neutral reaction drainage is necessary. For kiwi cultivation, heavy soils are necessary that must not be dried out or have an elevated pH value and a high proportion of active lime. It is considered that for the successful cultivation of kiwi, soil with at least 2-3% humus and a pH value of 6.5-7 is needed. The kiwi root is mostly very shallow in the soil, so that part needs to be well supplied with nutrients.
In relation to the actual preparation of the soil for planting kiwi, it is necessary to ensure some other conditions. For example, it is not out of place to investigate the chemical-physical properties of the soil, the results of which will show the necessary melioration interventions and fertilization. Also, the terrain on which it will be planted should be well cleaned and leveled. Mineral fuels should be spread evenly on the ground, and then the soil should be plowed to a depth of 40 cm. Planting kiwi requires mandatory provision of reinforcement before planting or after planting in the first year.
Temperature and climate
Kiwi does not tolerate extreme cold and it can be said that it requires warmer regions. In other words, during the winter and the rest period, it can bear temperatures down to -10°C for a short time, but the beginning of the growing season also means a sharp decrease in resistance to cold. This means that even temperatures of -1.5 °C can cause great damage very quickly. In spring, young shoots are sensitive to the cold, so late spring frosts can also cause some damage. If the fruit is left unpicked, it will also suffer from frost in autumn or winter. It is concluded that kiwi thrives in continental regions and in areas with a moderate continental climate.
Cultivation of kiwi
In relation to the cultivation of kiwi, a large role will be played by the arrangement of cultures, irrigation techniques and proper fertilization.
Matching cultures
One thing is known for sure, and that is that kiwi thrives well in areas of vines, peaches and nectarines, so good pre-cultures are those that thrive on light and moist soils, as well as drained soils with a neutral pH reaction.
Watering and irrigation
Drought is a great enemy of kiwi, so this plant needs to be provided with a drip irrigation system in plantations. In the initial, first year, one dropper per plant will be sufficient, and in the second year, one outlet tube with a dropper should be added. Later, if it proves necessary, two more are added. In addition to the aforementioned irrigation system, it is also possible to use sprinkler systems 60 cm above the ground.
Fertilization
In the first year of kiwi cultivation, it is necessary to fertilize each plant in the plantation a little, but often individually, with nitrogen fertilizer. Specifically, in the first year, 30 g of urea is divided into 3-4 portions and applied to 1-2 m2 in the area around the seedling during the growing season. It should be noted that if the plantation is irrigated, the process takes place from March or April until August. In the second year, the area to be fertilized should be doubled, and the same applies to the amount of fertilizer. The third year is the year when the entire area can be fertilized in two meals.
Maintenance and care
After the kiwi is planted, it is necessary to properly maintain the plantations and carry out winter and summer pruning.
Plantation maintenance
Kiwi will save you time in terms of frequent tillage because it roots shallowly in plantations. If soil cultivation is applied, it is necessary to cultivate the soil as shallowly as possible just to control the spread of weeds and preserve moisture in the soil. In doing so, special care should be taken not to damage the root. Heavy soils give the best results for kiwis. Since kiwi is a climbing plant, it will undoubtedly wind itself around the backrest. In the first year, in order to avoid this case, it is necessary to carry out pinching of the main sapling, approximately 3. Pinching should be carried out every 60 cm, i.e. when the sapling itself begins to twist suddenly at the top. Pinching means that the twisted part is removed, after which a new shoot will appear from the apical bud. In this way, a straight and strong sapling will be obtained, which will be the basis of the future trunk.
Pruning and shaping
There are generally two forms of buds. On the one hand, mixed buds provide vegetative and generative organs, and, on the other hand, woody buds provide only vegetative organs. From mixed buds, kiwi will bear fruit on the shoots, and from wooden buds, shoots without flowers and fruit will appear. For winter pruning, the dormant period should be observed, which is approximately in January or February. The best time for pruning is from 20 to 30 days before the start of vegetation. The purpose of pruning is to leave the most favorable number of one-year reproductive shoots and non-productive shoots, as well as the one that will serve to replace the main conductor. How many buds will be left depends on the variety. Summer pruning, which is also called “green”, tries to remove 70-80% of the total mass that is cut during the year. With it, the canopy is ventilated so that the plant receives the all-important sun rays all the way to the saplings. In one year, 3 green prunings are enough. The first can be carried out in April or May, the second after flowering, but before intensive fruit growth, and the third in early August or earlier.
Harvest
Kiwis are usually harvested at the end of October until the beginning of November. However, it is quite difficult and demanding to determine the right time to harvest kiwis because the outside of the fruit does not show changes like other fruit species, so that you know exactly when to pick them. Of course, the fruits should be picked when they reach physiological maturity.
Storage
The harvested kiwi fruits are stored in wooden crates and stored in refrigerators. Research shows that storage at low temperatures has a significant impact on the physical, chemical and nutritional properties of kiwis, as such storage contributes to better quality and firmness of kiwis, and extends the fruit’s shelf life without the kiwis changing color.
Diseases
Although it is quite resistant to diseases and pests, kiwi can sometimes struggle with these negatives. Different diseases can attack the fruit, root or leaf of kiwi, and the following stand out: Gray mold, Root rot and Bacterial spot.
Gray mold
Gray mold is the most well-known disease that attacks kiwi fruit. Diseased fruits quickly rot and perish. It appears in the form of a gray and thick micellar coating. According to global recommendations, this disease can be controlled by using fungicides or botryticide such as Kidan SC, Lupo SC, Sumilex SC 50 Fl, Mythos SC, Botril Sc and others.
Neck root rot
Neck root rot causes bark and cambium rot and necrosis in the area of the neck roots. Because it attacks the root, the whole plant can fail. The infection is recognized as the mycelium of the fungus, and humidity and high temperatures contribute to its development. For control, control with fungicidal preparations is recommended.
Bacterial spotting
Bacterial spot attacks kiwi leaves or flowers. It lives on the surface of the plant and is suited to wet and rainy weather. It is recognized by the spots and burns that appear on the leaves, so it is also called blight internally. A copper-based fungicide can be used to control this disease.
Pests
Shield ears
Aphids stand out as the most frequent pest of kiwi, and they attack the above-ground parts of the plant. In order to avoid the negative effects of this pest, it is necessary to regularly monitor their appearance and intensity. The insecticide Ovipron Top (15 l/ha, 1000 l water/ha) can be used for control.
The use of kiwi
Kiwi is recognized as a valuable food in medicine and cooking.
Cookery
Kiwi is usually eaten by peeling off the skin, but this procedure can also be skipped. You can simply cut off the top and eat the inside of the kiwi with a spoon. Whether you want to sweeten yourself with kiwi for breakfast, snack or dinner, depends on your preferences.
Kiwi cut into pieces can be a great addition to yogurt or a smoothie for breakfast, and it is also great in various fruit salads. Kiwi is also delicious as juice and jam, and can also be used as a topping for desserts if chopped.
Due to its specific taste, kiwi goes well with many savory dishes, such as ham, fish or white meat.
It is often nicknamed the “perfect marinade” for meat because it contains enzymes that will soften the meat.
Some people can be allergic to kiwi, so some caution is required when consuming it.
Medicine
Kiwi is extremely beneficial for health because it is rich in antioxidants, vitamins, fiber, potassium and many other valuable ingredients.
Kiwi contains twice as much vitamin C as, for example, an orange or a lemon. It is also rich in other vitamins such as vitamins E and K, as well as minerals from which potassium is extracted.
Vitamins C, E and A have antioxidant effects, and research confirms that kiwifruit can reduce the risk of developing macular degeneration characteristic of the elderly. It contains zeaxanthin and lutein, which are substances found in the human eye. Lutein is an assistant in filtering harmful blue light and thus kiwi helps protect the eyes.
Kiwi protects the digestive system because it is an excellent source of fiber, and as such it fights against colon cancer. Likewise, the fiber found in kiwi can reduce the level of bad cholesterol (LDL). Kiwi also protects DNA from oxidative damage, which helps fight cancer in general.
No less important, kiwi regulates blood pressure, suppresses the negative effects of sodium and regulates heart function. In relation to cardiovascular health, research shows that kiwi reduces the level of triglycerides by as much as 15%, thus protecting the health of the heart and blood vessels.
In addition to all of the above, kiwi accelerates metabolism, improves cognitive functions, prevents the onset of asthma and promotes weight loss.
Interesting things
Kiwi as an exotic fruit comes from China and is classified as a Chinese national fruit. It spread around the world from China, from where it first arrived in New Zealand at the beginning of the 20th century. Throughout history, many male and female kiwi varieties have been discovered.
Although it may not look like the most attractive fruit, primarily because of the small hairs on the skin that will not suit many, it is an extremely juicy fruit and has a characteristic sweet and sour taste. It is an interesting fruit in itself due to its wide use, advantages and qualities.
Photo: idaun / Pixabay