Persimmon: growing the crop from the soil to the cold store

Persimmon fruit on the tree — Figure 1. Persimmon at colour break. The crop has a reputation for being easy — and that reputation is exactly what costs money, because it hides three points where mistakes cannot be undone: water salinity, nitrogen, and harvest timing.

Savvas Pastopoulos, Agronomist MSc — Pastopoulos Agronomics, Neos Mylotopos, Pella, Greece

In Greece the persimmon is moving from the household garden to the commercial orchard, with the first organised producer groups forming in Pella [1]. The crop has three traps that do not forgive: it is among the most salt-sensitive fruit trees, excess nitrogen reduces yield instead of raising it, and storage quality is decided by soil calcium, not by sprays.

70–100hectares of commercial plantings in Greece [1]

< 0.65dS/m maximum irrigation water conductivity [2]

80–90kg N per hectare — above that, yield falls [2]

+20%fruit firmness from correct soil pH and calcium [2]

A note on units Greek growers work in stremmata; this English edition uses hectares throughout. 1 ha = 10 stremmata. Where the Greek edition gives «μονάδες ανά στρέμμα» (units per stremma, meaning kg of nutrient per stremma), the figure here is multiplied by ten to give kg/ha.

Contents

Where the Greek crop stands
Soil, climate and the water question
Cultivars and the four astringency groups
Planting, spacing and training
Pollination and fruit drop
Nutrition — and a correction
Diseases and pests
Harvest and postharvest
The key points
Sources

1. Where the Greek crop stands

Commercial persimmon plantings in Greece are estimated at 70 to 100 hectares, with average production of about 2,000 tonnes per year [1]. Two cultivars dominate: Rojo Brillante, which requires a deastringency treatment before consumption, and Jiro, eaten directly after harvest [1].

The tree is grown even in northern districts, tolerating temperatures down to −18 °C [1]. The first organised producer group is being founded in Pella.

Scale puts things in perspective

In Spain, production went in twenty years from quantities too small to appear in ministry statistics to 500,000 tonnes. The country now ranks third worldwide after China and Korea, with 90% of production in Valencia and based on Rojo Brillante [5]. Greek production of 2,000 tonnes is 0.4% of that.

And one observation that bears directly on planning in Greece: the shift towards PCNA cultivars, which need no deastringency, is proving difficult even in Spain, because compatible rootstocks adapted to Mediterranean soils are lacking [5].

2. Soil, climate and the water question

Persimmon tolerates some waterlogging, but excess water leads to increased shoot growth, higher incidence and severity of root rots, nutrient imbalances — some elements become toxic under waterlogged conditions — and leaching of nutrients from the root zone [2]. Where the depth of well-drained soil is marginal, mounds are used, though they dry out faster and may require up to 20% more water [2].

Salinity is the number one design mistake

Persimmon is sensitive to irrigation water quality. Conductivity should preferably be below 0.65 dS/m and chloride below 80 mg/L [2]. Every new water source is tested before use and existing sources are tested regularly.

In the leaf, the chloride standard has been set conservatively at 0.4%, because above 0.8% yield and fruit quality are adversely affected [2].

The practical measure: where water is marginal, heavier irrigations are required from time to time so that accumulated salts are flushed out of the root zone [2], and rootstocks with some salinity tolerance are chosen. In Israel, pulse irrigation is also used to alleviate salinity problems [2].

Soil pH is not a detail. Maintaining pH between 6.5 and 7.0 and soil calcium above 8.0 meq/100 g can increase fruit firmness by 20% and storage life by two to three weeks [2].

When fruit calcium is decided — and why it cannot be fixed later

Calcium uptake is determined in the window from budbreak to fruit set. There is a strong correlation between the mean minimum temperature of the six weeks preceding fruit set and leaf calcium; minimum temperatures of 10 °C and below markedly reduce uptake [2].

Uptake is also reduced by soil moisture stress, soil waterlogging and high humidity [2].

One error identified in practice: poor calcium uptake has been linked to micro-tube irrigation systems where the soil profile was insufficiently wetted during the critical period from flowering to three months after fruit set [2]. What matters is the wetted profile, not the emitter rating.

Sources: 1 2 5

3. Cultivars and the four astringency groups

Persimmon cultivars are classified by two independent criteria that combine into four groups [4]:

Astringency at harvest — astringent (A) or non-astringent (NA).
Effect of pollination on flesh colour — pollination-constant (PC), where fertilisation does not change the colour, or pollination-variant (PV), where the flesh darkens around the seeds and stays pale without them.

Group	Meaning	Examples and practical consequence
PCNA	Non-astringent, pollination-constant	Jiro, Fuyu. Eaten firm straight from the tree. No deastringency needed
PVA	Astringent, pollination-variant	Rojo Brillante. Deastringency treatment is obligatory
PVNA	Non-astringent only when seeds form	Quality depends on pollination — commercially unstable
PCA	Astringent regardless of pollination	Hachiya and similar. Eaten only fully soft or after treatment

Why this governs the whole orchard design In PV cultivars, a pollinator inside the orchard changes the product: it darkens the flesh and creates seeds. In Rojo Brillante, grown seedless, a pollinator is unwanted. In PCNA cultivars such as Jiro the question does not arise. A pollinator is therefore not planted "to be safe" — it is planted only if the specific cultivar requires it.

There is also Ribera Sun, a spontaneous mutation of Rojo Brillante with fruit about 30% larger in volume and weight, grown in exactly the same way. The cultivar is covered in detail in The persimmon cultivar Rojo Brillante.

4. Planting, spacing and training

There are no dwarfing rootstocks in persimmon This rules out very high-density plantings and the training systems that go with them [3]. Anyone planning a persimmon orchard with the logic of a modern apple or a cherry on Gisela is planning it wrong.

Spacing depends on cultivar vigour, soil fertility and training system [3]:

Vigour	Open vase	Central leader	Palmette
Moderate	5.0 × 4.0 to 5.0 × 4.5	5.5 × 4.5 to 5.5 × 5.0	4.5 × 3.0 to 4.5 × 3.5
High	5.0 × 4.5 to 5.0 × 5.0	5.5 × 5.0 to 5.5 × 5.5	4.5 × 3.5 to 4.5 × 4.0
Very high	5.0 × 5.0 to 5.5 × 5.5	5.5 × 5.5 to 6.0 × 6.0	4.5 × 4.0 to 4.5 × 4.5

On shallow or poor soils, with moderately vigorous cultivars, spacing can come down to 4.5 × 4.5 m [3]. Pruning has its own article: Pruning persimmon in the cultivar Rojo Brillante.

5. Pollination and fruit drop

Growth starts late, in April, and flowering occurs in the first ten days of June. Fruit set and productivity are positively correlated with pollination where it occurs [3]. Rojo Brillante, however, like Kaki Tipo, shows very high parthenocarpic fruit set [3] — it sets abundant fruit without fertilisation, and that is precisely why it is grown without a pollinator.

Fruit drop in persimmon is mainly a nutritional and hormonal matter, not a pollination one. Two documented causes:

Excess nitrogen. High rates increase fruit drop and reduce final yield [2].
Excess phosphorus. Above 235 kg/ha, phosphorus causes nutritional imbalance and impairs zinc uptake; zinc deficiency causes drop of young fruit [3].

The chain that is rarely connected Too much phosphorus → blocks zinc → the small fruit drop. The grower sees fruit drop and suspects pollination or weather. The cause may lie in the base fertilisation applied months earlier.

Sources: 2 3 4

6. Nutrition — and a correction

6.1 Nitrogen is not a friend

Past a point, nitrogen reduces yield

Nitrogen is the main regulator of yield and quality, but both very low and very high rates reduce yield, through poorer set and increased fruit drop [2].

Higher rates give slightly larger fruit but lower total yield, and at the same time reduce sugars, firmness and storage life [2]. It is one of the few cases where the grower pays twice: for the fertiliser, and in the quality lost.

6.2 The two schools — and why they disagree

Source	Nitrogen	Phosphorus	Potassium
Australian handbook [2]	80–90 kg/ha, optimum	—	—
Mediterranean guide [3]	100–150 kg/ha	50–70 kg P₂O₅/ha	70–100 kg K₂O/ha
Annual removal, per tree [3]	502 g	104 g P₂O₅	436 g K₂O

To this removal add 509 g CaO and 95 g MgO per tree [3]. At a density of 500 trees per hectare, 502 g of nitrogen per tree corresponds to roughly 250 kg N/ha — far above what either guide recommends applying. The difference is normal: a large part returns to the soil through leaf fall and prunings.

Removal is not fertilisation This is the commonest error in nutrition arithmetic. Removal measures what the tissues contain; fertilisation covers only what leaves the farm for good, after subtracting recycling from leaf fall and prunings and adding uptake efficiency. The two sets of figures must never be compared directly.

Correction to an earlier version of this article

The previous version stated that a yield of 40 t/ha requires about 25 units of potassium per stremma, and immediately after that international literature gives «around 120 kg of potassium per hectare, a figure entirely consistent».

25 units/stremma × 10 = 250 kg/ha ≠ 120 kg/ha

The two values differ by a factor of two and are not consistent. The Mediterranean recommendation is 70 to 100 kg K₂O per hectare [3]. The correction is recorded here explicitly.

6.3 The limits of leaf analysis

Index, one month before harvest	Target value
Leaf nitrogen	1.8 – 2.2%. Above 2.2% storage life is greatly reduced; above 2.5% quality deteriorates [2]
Leaf potassium	1.5 – 2.0% for maximum productivity and quality [2]
Calcium to potassium ratio	greater than 1.5 [2]
Calcium to nitrogen ratio	greater than 1.5 [2]
Leaf chloride	below 0.4% [2]

The finding that is rarely mentioned in the trade

Foliar applications of calcium and boron have only a small effect on fruit quality and storage life. Responses are variable and inconsistent, up to ten applications may be needed for any effect, the products are very expensive, and reliable field data on their efficacy is often not available [2].

Shelf life, by contrast, is strongly correlated with leaf calcium, which is governed by soil pH and soil calcium [2]. The investment belongs in the soil, not in the sprayer.

Potassium needs care in the opposite direction. Once exchange sites are saturated, surplus potassium leaches and displaces calcium and magnesium, accumulating in the subsoil [2]. Its effects on quality are variable — sugars and firmness increased only in some seasons [2]. The subject is analysed in Antagonisms and synergies among plant nutrients.

Calcium and magnesium are not remobilised within the plant, so they must be continuously available in the soil through the growing season [3]. Soil-applied boron increased fruit size and advanced ripening, with no phytotoxicity even at high rates [3].

Sources: 2 3

7. Diseases and pests

In Europe the persimmon remains a hardy species and is not an attractive host for very damaging pests [3]. That does not mean it has no problems — it means they are few, specific, and usually underestimated.

7.1 Two fungal genera dominate

In Florida, where the crop has been evaluated systematically since the 1980s, the two major limitations on production are fungi of the genus Botryosphaeria and of the genus Cercospora [4]. Leaf spot fungi cause premature defoliation and stress the tree [4].

Early autumn defoliation is not a cosmetic issue Early autumn defoliation delays and sometimes stops crop ripening altogether [4]. Persimmon is harvested late and the fruit can stay on the tree a further month for more colour and sugar [4]. A tree stripped early has no such option, however well the rest of the season went. Controlling leaf spot is an investment in sugars, not in foliage.

Susceptibility varies considerably by cultivar. In evaluations at Monticello, Florida, resistance to wood damage by Botryosphaeria scored from 3.5 to 8.0 on a ten-point scale depending on cultivar [4], and some cultivars are described explicitly as prone to premature defoliation or to late-season pathogens [4].

7.2 Scales and the other pests

In Europe the damaging pests are the Mediterranean fruit fly and the sesia [3]. In Florida the recorded pests are wood borers, psylla, and soft and armoured scales [4].

Four pests of direct relevance to Greek persimmon are covered separately on the site, with phenology and treatment timing:

The wax scale of fig and persimmon — Ceroplastes
Persimmon fruit damage by Pseudococcus comstocki
The orange spiny whitefly — Aleurocanthus spiniferus
The brown marmorated stink bug — Halyomorpha halys

Sources: 3 4

8. Harvest and postharvest

8.1 The order of things

In non-astringent cultivars harvest is by colour: the disappearance of green and the development of yellow to orange-red indicates marketable fruit [4]. They are eaten firm and are easier to store and market.

In astringent cultivars such as Rojo Brillante, fruit is harvested firm and given a deastringency treatment. The internationally established protocol, from the IVIA work in Valencia, is 95 to 98% CO₂ for 24 hours at 20 °C and 90% relative humidity. In Japan an alternative is used: spraying with 35 to 40% ethyl alcohol and holding in a sealed container for 10 days at 20.5 °C [4].

The temperature trap in the CO₂ treatment Exactly the same carbon dioxide treatment at 15 °C is clearly less effective and astringency remains. Concentration and time are not enough — temperature is an equal parameter. The full procedure, with the measurements and the usual mistakes, is analysed in The deastringency process for Rojo Brillante persimmon.

8.2 How long it keeps

Category	Storage behaviour
Astringent	Harvested soft or close to it, therefore they do not store well [4]
Non-astringent	Up to 30 days at room temperature. Colour intensifies, sugars stay the same, weight falls 7 to 10% [4]
Individually wrapped, refrigerated	In Japan, individually wrapped in thin polyethylene and stored at 0 °C for 4 to 5 months, with quality retained [4]

Only fruit free of imperfections stores well over a long period [4]. And early cultivars such as Izu have a shorter shelf life than late ones such as Fuyu [4].

8.3 The calyx — where everything meets

A physiological disorder of July becomes a rot in November

The calyx stops growing in July, while the flesh continues to enlarge until harvest. A cavity forms on one side of the calyx, causing uneven ripening, poor storage, and — above all — a site for disease infection [4]. It appears more often in non-astringent cultivars, and is less likely where the calyx is large relative to the fruit at flowering [4].

In commercial packinghouses in Valencia, losses on Rojo Brillante fruit were attributed to three fungi, with pathogenicity confirmed by Koch's postulates: Lasiodiplodia theobromae, Neofusicoccum mediterraneum and Neofusicoccum luteum [6]. Symptoms were irregular brownish soft lesions, mainly under and surrounding the calyx, expanding rapidly at room temperature, turning dark, and producing abundant white to grey mycelium [6].

The connection: all three species belong to the Botryosphaeriaceae — the same umbrella genus recorded as a major limitation in Florida [4]. The damage starts at the calyx region. Handling at harvest, stem cutting, selecting fruit without calyx separation, and packinghouse hygiene count as much as field sprays.

Sources: 4 6

9. The key points

What to take away

Water quality is checked before planting. Conductivity below 0.65 dS/m and chloride below 80 mg/L [2].
With marginal water, periodic heavier irrigations to flush salts out of the root zone [2].
Nitrogen above the optimum reduces yield, sugars, firmness and storage life [2].
Storage quality is built in the soil: pH 6.5 to 7.0 and calcium above 8.0 meq/100 g give +20% firmness and two to three weeks more life [2].
Foliar calcium and boron have only a small effect, with variable results and up to ten applications needed [2].
Too much phosphorus blocks zinc and drops the small fruit [3].
There are no dwarfing rootstocks — very high-density plantings are ruled out [3].
A pollinator only where the cultivar requires one. In Rojo Brillante seeds are unwanted.
Early autumn defoliation stops ripening [4].
Postharvest rots start at the calyx and are caused by Botryosphaeriaceae [6].

10. Sources

The numbers in the text refer to the list below.

[1] Persimmon: how the new plantings are made, first producer group founded in Pella (in Greek). AgroTypos. Source for the Greek area of 70 to 100 hectares, production of 2,000 tonnes, the dominance of Rojo Brillante and Jiro, tolerance to −18 °C, and the first producer group in Pella.
[2] Sweet persimmon grower's handbook — Persimmon nutrition and Key issues. Queensland Department of Primary Industries, Persimmon information kit, reprint with information current in 2005 (and the soil, water and nutrition chapter). Source for conductivity below 0.65 dS/m and chloride below 80 mg/L in irrigation water, heavier irrigations to flush salts, pulse irrigation in Israel, the 0.4% leaf chloride standard, optimum nitrogen of 80 to 90 kg/ha, the leaf range of 1.8 to 2.2% with storage life greatly reduced above 2.2%, the calcium to potassium and calcium to nitrogen ratios above 1.5, pH 6.5 to 7.0 with soil calcium above 8.0 meq/100 g giving +20% firmness and two to three weeks of storage, the small effect of foliar calcium and boron, the critical period of calcium uptake and the role of temperatures below 10 °C, mounds, and the effects of waterlogging.
[3] Bellini, E. and Giordani, E. Cultural practices for persimmon production. Options Méditerranéennes, Series A, number 51, CIHEAM. Source for the absence of dwarfing rootstocks, planting distances by training system and vigour, the low fertilisation demand, rates of 100 to 150 kg N/ha, 50 to 70 kg P₂O₅/ha and 70 to 100 kg K₂O/ha, annual removal per tree, the effect of phosphorus above 235 kg/ha on zinc uptake, the parthenocarpic fruit set of Rojo Brillante, and the description of persimmon as a hardy species in Europe.
[4] Sarkhosh, A., Andersen, P. C. and Huff, D. M. Japanese Persimmon Cultivars in Florida. SP101/MG242, UF/IFAS Extension, revised edition. Source for the classification into astringent and non-astringent and into pollination-constant and pollination-variant, Botryosphaeria and Cercospora as the major limitations, premature defoliation delaying or stopping ripening, the pests, the sugars, storage up to 30 days at room temperature with 7 to 10% weight loss, Japanese storage at 0 °C for 4 to 5 months, deastringency with 35 to 40% ethyl alcohol, and calyx separation in July as an entry point for infection.
[5] Badenes, M. L., Gil-Muñoz, F. and Blasco, M. (2022). Persimmon production in Spain. Acta Horticulturae 1338:17–20, ISHS. Source for Spanish production of 500,000 tonnes, 90% of production in Valencia, third place worldwide after China and Korea, and the difficulty of expanding PCNA cultivars for lack of compatible rootstocks adapted to Mediterranean soils.
[6] Palou, L., Montesinos-Herrero, C., Besada, C. and Taberner, V. (2013). Postharvest fruit rot of persimmon (Diospyros kaki) in Spain caused by Lasiodiplodia theobromae and Neofusicoccum spp. Journal of Phytopathology. Source for the three pathogens causing postharvest rot in commercial packinghouses in Valencia, the position of the lesions under and around the calyx, rapid expansion at room temperature, and confirmation of pathogenicity by Koch's postulates.

Disclaimer

This text is for information only. The fertilisation rates and nutrient ranges given are indicative and drawn from foreign literature, obtained under different soil and climate conditions. They are not a recommendation to apply. Final rates are set after soil, water and leaf analysis and an on-site assessment.

Plant protection products. Any use is governed exclusively by the approvals of the competent authority of the country of use and by the product label. The approvals listed at fyto.plantprotect.gr are issued by the Greek Ministry of Rural Development and Food and are valid in Greece only; they do not apply to other countries. Foreign publications frequently cite active substances that are not permitted in the European Union.

Foliar sprays: spraying trees carrying fruit can cause fruit marking and leaf burn. A prior trial on a limited number of trees is required, with the same product at the same rate, followed by 5 to 7 days of observation before general application. Spraying is done in the late afternoon or early morning, never in a heatwave and never on foliage under water stress.

Every intervention is carried out at the user's own responsibility, following an on-site assessment by a licensed agronomist. Pastopoulos Agronomics accepts no liability for the use of the information in this text.