Persimmons are sub-tropical, climacteric fruit, externally attractive with very little acidity and primarily sweet flavour. It belongs to the order Ebenales, Family Ebenaceae and genus Diospyros. The family Ebenaceae includes 6 genera and 400 species and the genus Diospyros includes 200 species of which only four species are cultivated. The Pronounciation of Persimmon is puh-si-muhn. The tamil name of this fruit tree is சீமைப் பனிச்சை.
This fruit was originated from sub-tropical region of China and Japan and they have been grown in China, Korea, and Japan as an important food source from prehistoric time. Many cultivars have been developed in these three countries. Diospyros kaki (Japanese Persimmon), Diospyros virginiana (Common Persimmon), Diospyros lotus and Diospyros oleifera are the cultivated species of genus Diospyros. D. kaki is native to China, Korea and Japan from which the large fruited garden and Orchard cultivar come. D. virginiana is native to United State and is smaller fruited and sweeter than kaki. D. lotus and D. oleifera are native to China and Korea whose seedling are only used for rootstock. China, Korea, Japan and Brazil are leading producer in the world.
In Nepal various varieties of Diospyros kaki and some indigenous strains are cultivated. Basically in ancient time astringent cultivar are cultivated in Nepal but nowadays the cultivation of pollination constant non-astringent (PCNA) type cultivar like Jiro and Fuyu is becoming popular (E.P. Simkhada, H. Gemma, 2005).
In this part, We will discuss all about the structure of Persimmon tree in detail as below:-
The height of the tree can reach up to 4.5 – 18 meters in height.
Persimmon plant bear ovate or obovate leaves that are shiny on top and pubescent beneath and are usually 7.6-17.8 cm long. Its branches are tender and brittle and are easily damaged by wind.
Persimmon is a dioecious plant however some plant may have hermaphrodite flower. So, plant may be monoecious, dioecious and polygamous-dioecious. Flowers are produced laterally on current season growth. Generally, the cultivar of commercial value only has female flowers, which produces seedless fruits. It bears yellowish white flower. Female flowers are large and cream colored with dark green four lobed calyx. Male flowers are small and occurred in 2-3 flowered cluster. Flowering starts in mid of March and continues up to second fortnight of April. The staminate (Male) flowers have 16 to 24 stamens while pistillate flowers have eight staminodes (Sterile stamen that does not bear pollen).
Botanically the fruit is called berry. The shape of fruit may be flat to round or elongated. The weight of fruit ranges from 50 to 300 g. The matured fruits are yellow to orange in color and become visually attractive. There is an enlarged persistent calyx at the base of fruit. Persimmon fruits are usually produced in clusters.
Classification of Persimmon
•Oriental Persimmon (D. kaki)
Oriental persimmon is commonly known as Japanese persimmon and is usually grown in China, Japan and Korea. The haploid chromosome number of D. Kaki is 15. However, the cultivar of D. kaki are tetraploid or hexaploid possessing 60 or 90 chromosome. Some cultivar of persimmon has high soluble tannin content that is responsible for astringency in Persimmon fruit. Astringency is a sensation that results when tannin bind salivary proteins and cause them to precipitate or aggregate, that produces a rough ‘sandpapery’ or dry sensation in mouth. According to the level of astringency upon harvest Persimmon fruit are classified as: Astringent type with high soluble tannin content and Non-Astringent type with low soluble tannin content and are also called as sweet persimmon. In astringent and non-astringent categories there are cultivars in which fruit astringency is affected by pollination (Pollination Variant) and the cultivar in which fruit astringency is not affected by pollination (Pollination Constant). In pollination constant type of cultivar the flesh color of seeded mature fruit turns orange-yellow but in pollination variant type of cultivar the flesh surrounding the seeded locule becomes brown through polymerization and oxidation of tannins.
Broadly speaking, This fruit can be classified into following four group on the basis of change in flesh color:-
1.Pollination Constant Non-astringent (PCNA)
In this type of cultivar, the cessation of tannin cell during the fruit development results in natural astringency removal and there is no significant change in the flesh color.
2.Pollination Variant Non-astringent (PVNA)
The seed produce large amount of acetaldehyde during the middle stage of development of fruit resulting in natural astringency removal and flesh color of fruit darken.
3.Pollination Constant Astringent (PCA)
The seed of this type of cultivar scarcely produce acetaldehyde and ethanol. Due to which flesh color does not change by seed formation and fruit produce astringent taste even it has large number of seed.
4.Pollination Variant Astringent
The seed of this type of cultivar produces less amount of acetaldehyde, so the coagulation of tannin is restricted around seed and astringency remains in the flesh and change in flesh color is restricted around the seed.
•American Persimmon (D. virginiana)
This is called common Persimmon and commonly grown in United States. The diploid chromosome number of American Persimmon cultivar is 90.
Some non-astringent varieties are as follows:-
It is the most popular non-astringent variety. An average temperature of 15oC or higher is required for its cultivation. It has pale yellow flesh with sweet taste and consist of 2 to 4 seeds per fruit. It is harvested in November.
This is second mostly cultivated variety and it is known for its excellent fruit quality and fine texture. The average weight of a fruit is 250 to 260 g. The harvesting season is late October to early November.
This is an old variety and has beautiful appearance. It is known for its fine texture and sweet taste. Fruit drop during maturation is the major problem associated with this variety. The average fruit weight is about 159 g.
This is a new and promising variety. This tree is vigorous and gives a good yield and have average fruit weight of 200 g. It has good storage ability.
Some astringent variety of are given below.
Astringency is due to tannins in flesh.
It has vigorous growing habit. It produces seedless fruit and fruit are flat in shape. The flesh of fruit of this variety becomes soft after treatment for removal of astringency. So, this variety cannot be kept for long duration. Fruits are generally harvested from mid October to November.
Fruits of this variety are suitable for making dried product and fruits are usually oblong-shaped. Fruit become dark after treatment for the removal of astringency. Average fruit is 230 to 240 g. It may produce seeded or seedless fruits and fruits are generally harvested after middle of October.
This variety is free from the problem of alternate bearing. Fruits are round shaped with rough texture.
This variety also have vigorous growing habit. Large sized fruits with good storage ability are produced. This variety is suitable for the removal of astringency. Average weight of fruit is 250 to 300 g. Fruits are harvested in November as it is the late variety.
For the successful cultivation of Persimmon, We need to many things about the requirements of this plant which are explained below:-
Persimmon can be cultivated in warm temperate and sub-tropical region. The mid hill region of Nepal at an elevation of 1000 m to 1800 m is found suitable for Persimmon cultivation. This fruit can be grown in east-west range of mid hills area of Nepal. The agro-climatic condition of surrounding area of Kathmandu valley is suitable for Persimmon cultivation. The fruit has been successfully grown at an altitude of 1,830-2,500 m in China and above 1000 m in Indonesia. Suitable range of temperature is 14-22oC. The annual temperature for perfect sweet persimmon ranges from 14.6-15.7o C. Perfect sweet persimmon need warmer temperature than astringent type to remove astringency. Perfect sweet persimmon is week winter hardiness and it suffers from winter chilling injury when exposed to temperature below -15o C while the astringent type persimmon fruit can tolerate temperature below -25o C.
Persimmon grow best on loamy soils. Light, Sandy soil are not suitable for Persimmon cultivation. This fruit cultivation can also be done in heavy clay soil if good drainage facility is available. A pH range of 5.5 to 6.5 (5-7) is preferred for cultivation of this fruit.
Persimmon can be cultivated or propagated by both sexual and asexual methods:-
Mature seeds are used to propagate rootstocks. The fresh seeds of Persimmons can be used to grow seedlings. For better germination, seeds should be stratified approximately at 45 C for 60-90 days. Now, these seeds can be grown in boxes at 70 F. Seedlings are lined out in the spring when the soil temperatures are 55°F or higher. For better lateral root development, Seedlings should be transplanted when they become 6 to 8 inches tall. Seedlings can be grafted at the end of one season’s growth, when the rootstock and scion are dormant. Germinates best at 28oC.
Under asexual propagation, We have Grafting, Cutting, Top Working and Micropropagation which are explained below:-
Grafting is the process of unification of stock and scion of two different plants of same species. For this fruit, Dormant period is the best period for grafting when the rootstocks become ⅓ inch in diameter. The diameter of scion should be ¼ to ⅓ inch with height of about 3 to 5 inches and 2 to 4 buds. It is important to take scion from a healthy and well lignified parent plant during winter dormancy period.
The various method of grafting used in the propagation of persimmon plant includes:-
1.Whip and tongue graft
The rootstock and scion should be between 1/4-1/2 inch and equal in diameter. First cut both stock and scion diagonally and second cut down the stem of both stock and scion. After the rootstock and scion have been prepared in this way, the two are inserted into each other, then bound and wrapped with parafilm or wax.
2.Cleft (Wedge) Graft
Cut off a few inches off the top of the rootstock to remove any dead wood, then split it down the middle approximately 2-3 in. A scion of nearly the same diameter should be inserted into a wedge and slid into the split in the rootstock. Bind and wrap to prevent desiccation.
In this method, we should make a deep cleft at the end of scion and a wedge at the end of rootstock. After that, the wedge of rootstock is fitted inside the cleft of the scion.
4.Side Veneer Graft
The scion should be prepared by making one long slice at an angle, with a very short one on the opposite side. For rootstock, cut the stem from the side which goes inward as we go downward and then insert the scion in that cut. The scion should be inserted into this cut, bound, and wrapped.
To propagate rootstocks with cutting use softwood cuttings, root with bottom heat under mist, and treated with indole-3-butyric acid (IBA). The procedure of cutting techniques includes the following steps:-
➡️The cuttings of persimmon should be taken during mid spring after new leaf and twig emerges on the branches. Prepare a rooting pot before gathering the cuttings so they can be potted quickly after.
➡️Take a 6 inch pot and fill it with perlite and sand at the ratio of 1:1. After that, add water in the pot mixture until the water flows out from the drainage hole at the base of the pot.
➡️Now, take a 4 to 6 inch long softwood cutting of Persimmon. Sever the cutting 1/8-inch below a leaf node using sharp, clean shears. Make the cut straight across rather than angled. The leaves of the cutting should be removed from the lower half. It helps to reduce transpiration and increase the chance of successful growth.
➡️Measure out 1 tablespoon of 0.1-percent IBA (indole-butyric acid) rooting hormone talc and spread it on a sheet of paper. Now, dip the cuttings into this hormone. This helps to increase the rooting.
➡️Make the hole in the pot mix deep enough to hold the bottom half of the persimmon cutting. Insert the hormone-treated end of the cutting into the planting hole and press the moistened sand mixture firmly against the stem.
➡️Place the potted persimmon cutting inside a lightly shaded, ventilated cold frame. Warm the bottom of the pot with a propagation mat set to 75 F. Close the ventilation on the cold frame at night and whenever daytime temperatures fall below 60 F.
➡️Mist the cuttings with water twice daily to keep the leaves hydrated and we should check the moisture level of pot mix before misting. Add water whenever it feels mostly dry in the top 2 inches. Do not let it dry out completely.
➡️Check for roots in approximately one month by gently tugging on the base of the persimmon cutting. Feel if it is affixed to the sand mixture by roots. Remove the propagation mat one week after rooting.
Transplant the persimmon cutting into a 10-inch container filled with mildly acidic potting soil one month after rooting. Grow it under light shade during the summer with 2 inches of water per week.
It is done during late February to mid March. Trees (3-8 years old) grafted at 1m height with 5-10 scions.
Micropropagation is the technique of producing large number of plants from a plant tissue. Micropropagation produces identical plants. Though it is an expensive procedure, it helps when there is a limited source of plant tissue.The plants produced by micropropagation perform better.
For example, micropropagated trees of cultivars of persimmon:- ‘Jiro’ and ‘Hiratanashi’ grow easily and more quickly than grafted trees and showed less shock at transplant compared to grafted trees.
Adequate water is required for the establishment of newly planted trees. Frequent irrigation for 2 to 4 times per week is required after planting. The quantity of irrigation is determined by several factors including rainfall, soil type and evapo-transpiration. On maturity fruit become more drought tolerant.
Water availability is essential during the main growth phase in first few month of season. However, water availability is important during flowering and fruit set. Regulated deficit irrigation (RDI) applied early in the season reduces fruit drop but leads to production of smaller fruit during harvest time and if RDI applied later in the season, fruit color development took earlier (Ali Sarkhosh, October 2020). This plant is susceptible to water stagnation condition as it causes root asphyxiation. So, the field should be properly drained.
When natural precipitation is unable to fulfill the water requirement of plant, irrigation is applied in July and August. The method of irrigation depends upon water availability and tradition. In some areas infiltration from furrows is employed and in some area localised irrigation are also used. Micro sprinklers and drip irrigation are effective means to supply water.
A total of 2-2.5 m3 water per plant is administrated. In Nepal, irrigation is carried out by the submersion of beds or depression created around the plant. Two or three watering are administrated during August and September.
The nutritive needs of persimmon vary in the different periods of the life cycle. During bearing phase, the plant’s requirement of nutrients varies over the course of the year, above all as a function of the various vegetative and productive phases: sprouting, growth of buds and leaves, flowering, fruit set, fruit development, flower induction, ripening, accumulation of reserves, entry into dormancy.
From the nutritional point of view, the phase of bud growth is particularly critical. This phase has an intense pace and for such a brief period of time, and at the beginning it takes place exclusively thanks to the nutritional reserves accumulated the previous year since persimmon has a late foliation. The general recommendation of a fertilizer in a soil which contains sufficient nutritive substances and has undergone good basic fertilization, annual doses of 100-150 kg of N, 50-70 kg P2O5, and 70-100kg of K2O are able to supply an adequate nutritional support for persimmon (Bellini E. ( ed.), 2002).
A research was conducted in south-korea by using the split application of oil cake in non-astringent persimmon tree. In this study zero (control), single application (150 kg N/ha in April), two applications (105 and 45 kg N/ha respectively in April and July) and three applications (60, 45 and 45 kg N/ha respectively in April, June and August). Fruit yield was found higher in three split application (Byeong-Sam Kim, 2016).
This fruit is planted during July or early August. A pit of 1 m3 is dug. Spacing depends upon cultivar and soil type. For dwarf, semi-dwarf and vigorous cultivars spacing should be 5.0 *2.5 m, 5.0 *3.0 m and 6.0* 4.5 m respectively.
There are some activities to carried out after the plantation of tree and before its harvesting which are called Intercultural Operations. Some intercultural operations to be performed in period of this fruit cultivation are:-
Training and Pruning
Persimmon tree need to be trained to provide a structural strength, to make intercultural operation easier and for Better light penetration.
Dwarf cultivar are suited to Centre leader system of training whereas semi-dwarf cultivar are suited to palmette system.
Pruning is also an important practice. The best time to prune Persimmon is in the winter while the tree is dormant. The diseased, dead and broken branches are completely removed while all other branches are trimmed to 1/3 to a bud. Summer pruning is also practiced. Summer pruning improves the fruit size and color. Heavy pruning should be avoided.
Fruit thinning is important to regulate the crop load and it also helps to overcome the alternate bearing tendency of crop. The crop regulation can be done through judicious pruning during the winter. Thing of fruit can be done either manually or by the application of chemicals. Hand thinning is done just after the first natural fruit drop or after 3 weeks of flowering. Fruit should be placed 6 inches apart in order to prevent rubbing damage to adjacent fruit.
Fruit Growth and Development
In Persimmons, fruit develops from flowers borne on large inflorescence of current season growth. In most of the Persimmon varieties fruit develops parthenocarpically and leads to the production of seedless fruit. However, in some varieties where pollen are available seeded fruit are also found. Persimmon fruit is a climatric fruit and is botanically berry consisting of homogeneous parenchymatous pericarp.
The fruit development occurs in two periods. The first period is about two months and second period is about approximately two and half month. Fresh weight and diameter increases while the percentage of nitrogen decreases rapidly during the first period and in second period increase in diameter is somewhat slower. Fresh weight increases at a lesser rate during the second period, and the percentage of nitrogen decreases slowly for a time and abruptly increases as maturity is approached. Dry weight accumulation occurs rapidly during the second period i.e. about 70-75% of dry weight accumulation occurs during this period. The persimmon fruit have high levels of sugar and organic acids and moderate levels of fatty acids which significantly change during maturation and ripening.
The major organic acids found in Persimmon fruit were citric acid and malic acids, which increases through the immature and mid-ripe maturity and then level decreases during the overripe fruit. At maturation stage fruit color changes from green to yellow-orange or red.
Persimmon fruit are harvested during autumn. Proper handling of during and after harvest is essential to obtain good quality Persimmon for higher market price. Generally, this fruit is clipped from the fruit trees by the help of secateurs.
At harvesting, calyx is left attached to the fruit. Generally, two or three peaking period are required depending upon the cultivar and seasonal conditions. Fruits harvested at immature stage do not soften evenly after harvest and may be partly astringent and generally lack flavor. So, the persimmon fruit should not be harvested during immature stage. Non-astringent type can be picked when firm, beginning in the yellow/orange phase through full color. Astringent type should be picked at full color, when soft or nearing softness.
Persimmon fruit become ready to harvest when they are fully orange-yellow to orange-red in color and there should be no visible green background. Fruit maturation is also accompanied by increased soluble solids content (SSC), reduced fruit firmness and fruit astringency. In Pollination Constant Non-astringent (PCNA) type cultivar, soluble solid measurement is a good indicator of fruit maturity.
Some Persimmons fruits are astringent in taste. Astringency is due to the water soluble tannins. Tannins are found in large special cell ‘tannin cells’ which are scattered on the flesh of the fruit. Various treatment are followed to convert this soluble tannin to insoluble form. In certain cultivar, the acetaldehyde and ethanol produced by the seed coagulate or condense the soluble tannin into insoluble form and astringency is removed.
✓Removal of Astringency
Some cultivar of persimmon bear fruits that produce astringency and require special post- harvest treatment before commercialization to remove astringency. For the removal of astringency there should be condensation of soluble tannins with the acetaldehyde that accumulated under anaerobic condition. Following are the methods employed to remove astringency in this fruit:-
1.Warm water treatment
It is the traditional method of removing astringency in Persimmons fruit. In this method, fruits are dipped in warm water at 40oC for 15 to 24 hour. However, it deteriorate the fruit quality and so not commonly used.
2. Alcohol Treatment
In this method ethanol is commonly used. For the removal of astringency at first the persimmon fruit are packed in a cartoon of about 5 to 15 kg and are sealed after spraying them with aqueous ethanol (30% to 40%). After this the fruits are stored at the temperature of 10 to 15oC for about 10 to 15 days (Kato, 1990). This method produces firm, high-quality fruits with jelly-like texture, sweet taste, and good orange color. This takes comparatively long time. So, this method is commercially impractical.
3. Carbon Dioxide Treat
CO2 treatment is usually applied for near table-ripe fruit. In this method Persimmon fruit are kept in high CO2 concentration for about 1 to 3 days. This method can be employed commercial production of Persimmon as short period is required.
4. Dry ice method
Dry ice method can also be employed for astringency removal. 20 kg of fruit requires 240 g ice dry ice and after 5 days astringency is completely removed. Due to chilling damage by dry ice, fruits have short shelf life of 1 day.
Persimmon fruits are also sensitive to chilling injury at low temperature. Chilling injury is a major cause of deterioration of persimmons during marketing. Many fruits including Persimmon need suitable storage temperature to prevent from chilling injury. Browning, intense gelation and softening are chilling injury symptoms in persimmon fruits. 0°C temperature and relative humidity >80% is the best storage condition for Persimmon (Khademi, 2012).
Diseases and Pest
Diseases and pest can destroy our cultivation totally. Therefore, It is necessary to know all the diseases and pest for the successful cultivation of Persimmon.
Some of the diseases are explained below:-
1. Persimmon Anthracnose
Img Source:- Research Gate
It is the fungal disease caused by Colletotrichum gloeosporioides. It is the fungal disease thriving in wet condition and often appear in spring. Anthracnose symptoms first appear in spring on twigs, leaves and fruit as darkish oval or elliptic spots. Under favourable condition, these adjacent lesion may coalesce and form large sunken necrotic lesion. Anthracnose also causes the immature fruit drop in Persimmon. Selection of resistant variety and maintainance of proper drainage facility would be beneficial to overcome this problem.
Img Source:- Vikaspedia.in
It is caused by Agrobacterium tumifaciens. It causes tumours and cancer like growth in lower stems and roots. The bacteria may enter through wounds in plant surface. Mechanical injuries of roots and other plant parts by cultivation equipment, animals and insects are also the important point.
3.Root and crown rot:
It is caused by phytopthora spp.
It is caused by Botrytis cinerea
It feed the plant sap from leaf and stem. Honey dew and sooty mold further disfigure infected plant which may eventually be killed.
It leads to copius honey dew production and high probability that sooty mold fungus will disfigure host plant and foliage of adjacent plant species.
In case of fruit flies adult are not so destructive. Larvae feeding in fruits are most damaging. It causes internal rotting of fruits associated with maggot infestation. Infected young fruits becomes distorted, callused and usually drop.
4.Twigs girdlers and borer
Major damage is caused by larva which creates galleries (mine) between bark and wood. A full grown larva may bore from 1 to 2 inches deep in the wood of bark.
Problems in Persimmon Cultivation
Here, We have listed some of the problems that you may face during the Persimmon cultivation:-
Fruit trees show many irregularities in bearing habit. During one year the fruit tree bears heavily whereas little or no production in following year. The tendency of fruit tree to bear heavily on alternate year is called as biennial bearing. Persimmon fruit also exhibit such problem. Fruit thinning, deblossoming and light summer pruning can be adopted to overcome the alternate bearing problem.
Thus – Persimmon is a great and delicious fruit that has many advantages. We can earn decent from the cultivation of this fruit.
1. Govind Raj Joshi (AFU, Chitwan, Nepal)
2. Hari Khatri (AFU, Chitwan, Nepal)
3. Himal Gautam (AFU, Chitwan, Nepal)