Pests and diseases of persimmon (Diospyros kaki) in Europe and Greece: epidemiology, differential diagnosis and action thresholds

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

Persimmon is being planted in Greece continuously and the area is increasing year on year, with new orchards all over Greece and with growers organising around the crop [20]. The phytopathological problems are increasing along with the area. Greek orchards already record mealybugs under the calyx, wax scales, mussel scale, sooty mould on the foliage and Mediterranean fruit fly attack. What follows is what is recognised in each case, what it is separated from and where the action threshold lies.

1. Greek persimmon growing today, and the three reasons the problems grow together with the area

A 2023 account of the new orchards in Pella gives the shape of the orchard [20]: cultivars Rojo Brillante and Jiro, palmette at 3.5 by 2 metres for growers coming from peach and plum, open vase at 4 by 5 metres for the rest, that is 500 to 700 trees per hectare, bearing from the third year. The cultural background is covered in the article on growing persimmon.

These orchards are for the most part young, and age is the factor that explains why the problems grow together with the area. Three things happen to every crop that passes from the young planting phase into the mature orchard phase, and all three have already happened to persimmon elsewhere in the Mediterranean.

Inoculum accumulates. Foliar and fruit pathogens overwinter in fallen leaves and dead wood. A three year old tree has neither leaf litter nor dead wood. A fifteen year old tree has both. In South Africa, which has grown persimmon in a Mediterranean climate since 1998, orchards began to show dieback and cankers at fifteen years of age [12].

Density closes the canopy. At 3.5 by 2 metres the planting closes quickly. Foliage dries later, spray penetration falls, and the wetting hours each fungus needs are reached more easily.

Pathogens travel with planting material. Circular leaf spot did not exist in Spain before the crop grew there. It appeared when the crop grew, in Valencia in 2008, and the first formal report was published in 2010 [5].

Sources: 5 12 20

2. Circular leaf spot, Plurivorosphaerella nawae: epidemiology, infection window and the role of the irrigation system

The pathogen is Plurivorosphaerella nawae, formerly Mycosphaerella nawae, EPPO code MYCONA [7]. It was first described in Japan in 1929 and is prevalent in Korea. In Spain it was detected in 2008 in Valencia province [5], and in Italy it was reported in 2021 [6].

Symptoms are necrotic leaf spots, chlorosis and premature defoliation. The fungus infects the leaves only. The fruit, however, ripens early, softens and drops as a consequence of defoliation, and that is where the severe economic losses come from [2].

2.1 Where the inoculum overwinters, and under what conditions ascospores are released

The fungus reproduces in pseudothecia formed in the leaf litter. Ascospores mature in spring and are released when temperature and moisture coincide. In the Spanish measurements, made in a wind tunnel under controlled temperature [3]:

• Release begins around 10 °C and increases exponentially to 16 °C. Because persimmon vegetative growth starts above 10 °C, temperature is not a limiting factor when susceptible tissue is available.
• With 0.1 to 0.5 mm of water, that is with dew, very few ascospores are released. With 1 to 50 mm significant numbers are released. 1 mm is enough, and larger volumes of water do not increase the number further.

2.2 Infection period and latent period: the difference between Spain and Korea

The difference between the two countries is the central finding, and it shows exactly how dangerous it is to import a foreign calendar.

The Spanish conclusion is that the fungus adapted to semi-arid conditions by altering its period of inoculum production to coincide with rains and with the availability of susceptible tissue. Temperatures were limiting neither for release nor for infection, and ascospores disseminated and infected under relatively dry conditions [2] [4].

2.3 What is documented to work and what does not

Three things are documented and transfer, because they do not depend on any Greek product approval.

Post-infection sprays are ineffective. In Spain preventive spring applications showed good efficacy, while post-infection ones did not work [2]. With a latent period of four months, by the time the lesion appears the season has already been decided.

The leaf litter is the inoculum. Removing infected leaf litter is described as critical for reducing inoculum, and it is the main measure in organic production, where conventional fungicides are not available. The litter can be incorporated and decomposed in the soil by ploughing or similar tillage. Burning and composting are also effective, but more costly [2].

Forecasting is feasible. The ascospore discharge test detects physiologically mature ascospores in the leaf litter one to two weeks before they are released. The technique is now used in Spain within a decision support system that predicts the onset of release and the infections that follow [2]. It is the kind of tool Greece would need before, not after, a first epidemic.

In Spain the disease has in recent years been managed with three to four sprays covering the spring infection period [2]. The active substances used there are not named here, because approvals are national. What is permitted on persimmon in Greece is shown only by the Ministry database [22].

Sources: 2 3 4 5 6 7 22

3. Angular leaf spot, Pseudocercospora kaki, and Pestalotiopsis leaf spot: separation by lesion shape and number

Two further leaf spots attack the foliage and neither touches the flesh of the fruit. Their damage is indirect and delayed, as with circular leaf spot: they strip the canopy before its time, so the current crop stays smaller and the tree fails to build the carbohydrates that finance next year's flowering [1].

3.1 Angular leaf spot, Pseudocercospora kaki

The cause is a species of Pseudocercospora, most likely Pseudocercospora kaki [1], which is also recorded in Taiwan as one of the common persimmon pathogens [14]. The shape of the lesion is the feature: the veins stop its spread, so the spot comes out angular rather than round.

Survival is as hyphae inside the leaves and leaf bases, and spores last five to six months in fallen leaves. Dissemination is chiefly by water [1]. Two details transfer as they stand, because they do not depend on climate: there is a varietal difference in susceptibility, with Izu appearing susceptible, and the disease is worse under netting, evidently because netting holds humidity and slows leaf drying.

3.2 Pestalotiopsis spp. leaf spot, with shoot cankers in Spain

It produces large greyish brown circular lesions with concentric rings, usually one to three per leaf, with small black fruiting bodies visible on the lesion surface. When lesions cover more than one third of the leaf, defoliation follows. It also attacks the calyx sepals, one to four per fruit, with brown to black necrotic areas, and this leads to premature ripening and fruit drop [1].

The European connection is direct: in Spain the disease also causes cankers on shoots, and the pathogenicity of Pestalotiopsis diospyri was demonstrated on sweet persimmon there [1]. Pestalotiopsis clavispora is also isolated from postharvest stem-end rots in Spain [8], so the genus works both in the field and in the cold store.

Sources: 1 8 14

4. Anthracnose of fruit and shoots, Colletotrichum spp.: latent infection from fruit set to harvest

The nomenclature needs care, because three names circulate for things that are not the same. In China, where persimmon is native, Colletotrichum gloeosporioides is described as the major pathogen of the crop in almost all areas where it is extensively grown, with economically important losses [13]. The small scattered specks are attributed to the same species, while the sunken lesions on leaves and fruit are attributed to Colletotrichum kaki [1]. True persimmon anthracnose, however, is today attributed to Colletotrichum horii, a species reported in Asia, Oceania and South America, which causes lesions on fruit and shoots and requires intensive spray programmes [2]. It is not established in Europe, and section 18 treats it as a threat.

The interesting finding is that these specks are associated with a stress factor that confines the disease to this form instead of letting it become full anthracnose, something also shown in avocado [1].

The mechanism is the same as in every latent fruit infection. The fruit is susceptible from fruit set to harvest, the fungus penetrates the peel and remains dormant until ripening, and wakes when the fruit ripens, is injured or is stressed [1]. C. gloeosporioides overwinters as mycelium in and on diseased tissue, its conidia are water-borne and spread by splashing rain, so infection is highest during the wettest periods of the growing season [13].

The factors linked to anthracnose severity are all cultural and transfer intact [1]: orchard age above twenty years, large trees that are hard to spray in the upper third, light pruning that holds moisture on leaves, fruit left unpicked acting as a spore source, prunings left under the tree, and proximity to abandoned orchards of other hosts. The genus Colletotrichum attacks avocado, mango, banana, fig and others, so in Greece the neighbouring fig is the practical equivalent of the Australian avocado.

Sources: 1 2 13

5. Cankers, twig blight and wood diseases, Diaporthe, Eutypella and Botryosphaeriaceae: entry through pruning wounds

The most obvious symptom is not the canker but sporadic and delayed budbreak in spring. New shoots emerge with small yellow leaves and an elongated, etiolated form. New laterals die back from the tip, and whole sub leaders die back towards the central leader without dormant buds breaking. One year old shoots show ink dark cankers, and a cut reveals internal wood that is necrotic or stained [1].

The Australian work left the cause open, with isolations of Phomopsis and Diplodia but no proof of pathogenicity [1]. The picture was clarified in South Africa, in a Mediterranean climate, where the crop was introduced in 1998 and fifteen year old orchards began to show dieback and cankers [12].

Two elements of the same work are directly usable. The first is the entry route: wood pathogens enter mainly through pruning wounds and sucker wounds, and their spores are air-dispersed [12]. In Australia a second route is added, the fresh leaf scars during leaf fall [1].

The second is the rootstock. Of the two orchards used for pathogenicity tests, one was grafted on Diospyros kaki and the other on Diospyros virginiana. Mean lesion length after four months ranged from 30.7 mm to 53.9 in the first and from 36.7 to 65.2 in the second, with a statistically significant difference in favour of D. kaki [12]. In Spain, correspondingly, Botryosphaeriaceae were detected on pruning wounds and in trunk cankers, but at low prevalence [2].

Sources: 1 2 12

6. Grey mould, Botrytis cinerea, and sooty mould: two problems associated with the calyx

6.1 Grey mould, Botrytis cinerea

Botrytis cinerea produces discrete grey lesions on young leaves and calyces, which enlarge, coalesce and lead to premature senescence and leaf fall. Calyx damage significantly reduces fruit size, and infected petals sticking to the young fruit leave scars [1].

The only quantitative figure is also the most useful: four to six hours of free water on the plant surface are required for spores to germinate and infect [1]. In the field it ranks as a minor disease, more frequent in cooler climates. In the cold store it changes weight: in Spain grey mould is one of the pathogens causing latent stem-end rots and is also isolated from fruit after storage [8].

6.2 Sooty mould: a symptom of sap sucking insects, not a disease of the plant

Sooty mould is not a disease of the plant. It is fungi of the genera Capnodium, Fumago, Scorias and others, growing on the honeydew of sap sucking insects without penetrating the tissue [1]. The damage is twofold and entirely indirect: it reduces the light reaching leaf and calyx, hence photosynthesis and fruit size, and it downgrades the fruit commercially.

The conclusion is categorical: if the insects are controlled, sooty mould is controlled, and the single most important measure is restricting the movement of ants into the canopy [1]. For fruit already covered, cleaning is done with water and detergent and light brushing, and some growers have built semi automated washing systems using pressurised water [1].

Sources: 1 8

7. Postharvest rots in storage: alternaria black spot, stem-end rots and wound rots

Here the Mediterranean experience is the fullest that exists, because Spain and Israel store large volumes of astringent cultivars and have measured the problem.

7.1 Alternaria black spot, Alternaria alternata, the main postharvest disease

Black spot is by a considerable margin the most important postharvest disease of Rojo Brillante in Spain, irrespective of season and orchard, in both latent and wound infections [8]. In Israel it is the main factor that impairs quality and reduces the storability of Triumph [9].

The figures are serious. In commercial Spanish packinghouses in the Valencia area, losses of up to 30% of fruit from black spots on the peel have been observed [8].

This bears directly on Greek practice. In the article on deastringency the storage limit for Rojo Brillante at 1 °C with 1-MCP is given as about 40 days. At 40 days black spot has not had time to show. The observed limit is therefore not only a matter of firmness: it is also the point at which black spot does not have time to become visible. Anyone who tries to push storage to three months will meet the Spanish problem.

7.2 Where and when the fruit is infected, and the role of irrigation

Three findings change how the problem is handled, and none of them concerns the cold store.

Inoculum is everywhere and present all season. In Spain the various inoculum sources were broadly distributed within affected orchards, and A. alternata conidia proved highly tolerant of dry periods, so airborne inoculum was available throughout the growing season [2].

Latent infections concentrate at the end. They were most frequent during the three-month period before harvest [2]. That defines the window in which protecting the fruit makes sense.

The damage starts at the stem end, and irrigation defines it. In Israel it was shown that the fungus colonises the upper, stem-end tissue and not the bottom end. The stem end produces more ethylene and carbon dioxide in early stages, and in later stages has greater cracked area and reduced chlorophyll [10].

7.3 Latent pathogens and wound pathogens: two groups needing different management

Species list from the Spanish survey [8].

The most useful figure for management is that Rhizopus stops growing below 8 to 10 °C, so the speed of precooling is the critical measure, with a target of 10 °C [1].

7.4 What is permitted in the European Union, and how much the timing of the intervention matters

In Spain and the other European Union countries no conventional fungicide is permitted for postharvest treatment of persimmon, so control relies on a combination of alternative methods [8]. The same holds in Australia [1]. What applies in Greece is shown only by the Ministry database [22].

Two results deserve particular attention. The first concerns deastringency itself. In trials with short 48 hour gaseous treatments, carbon dioxide at 95 kPa reduced black spot by 30 to 40% after 40 days at 1 °C, but the reduction had disappeared by 82 days. After 10 days at 20 °C no treatment significantly reduced incidence, and severity was in some cases higher on treated fruit [11]. The treatment the grower already applies to remove astringency is not simultaneously protection against rot.

The second concerns the timing of the field intervention. In Israel, a preharvest application fourteen days before harvest, combined with the commercial chlorine dip, reduced the infected area by 60% compared with the dip alone, while the corresponding application thirty days after fruit set gave only 3% [9]. Timing, that is, matters twenty times more than the intervention itself. The chlorine dip is an Israeli commercial practice and is not an approved postharvest treatment for persimmon in the European Union.

Sources: 1 2 8 9 10 11 22

8. Diseases of the collar and the root system: crown gall, vascular wilt and root rots

8.1 Crown gall, Agrobacterium tumefaciens

The cause is the soilborne bacterium Agrobacterium tumefaciens, which infects mainly through wounds, that is at grafting and transplanting. The bacterium survives in soil for two years and more waiting for a host [1]. The disease hits young plants hardest and often kills them, while older ones weaken but usually survive.

Two points are reassuring. First, Diospyros kaki is the most resistant species of the genus to crown gall. Second, the disease is described as minor and rarely seen in persimmon orchards [1]. The measure with the best return is avoiding new wounds and, on ground with a history, growing grasses for up to three years before replanting.

8.2 Vascular wilt at the collar, and the identification problem

Collar wilt is attributed to the bacterium Pseudomonas solanacearum, under its former name [1]. That organism is today named Ralstonia solanacearum, is on the EPPO A2 list and is a Union quarantine pest, listed in Annex II B of Regulation (EU) 2019/2072 [19] [21].

The picture described is useful as a symptom, independently of the cause. In young trees wilt is rapid, preceded by heavy leaf fall, and the leaves that remain hang almost vertically. In older trees the decline is slow, about two years, without yellowing, with small pale leaves, sparse foliage, sunburn on bare branches, and prolific flowering with fruit that never reaches marketable size. Wilt usually shows in late summer, when crop load is heaviest, and a transverse cut at the collar shows extensive staining of the outer growth rings [1].

8.3 Root rots and Phytophthora

The symptoms are pale yellow foliage, weak flushes, and in severe infections rapid death, with black roots and rotted fine root tips. In Australia Cylindrocladium and Pythium species are implicated, while it is notable that Phytophthora is rarely isolated from persimmon roots despite repeated attempts [1]. In Spain root rot problems caused by Armillaria mellea and Rosellinia necatrix were recorded, but at low prevalence [2]. In Taiwan Phellinus noxius, Ganoderma lucidum and again Rosellinia necatrix are recorded [14].

One reference figure places the problem at its proper scale: it is common for a persimmon orchard to lose 5 to 10% of its trees over ten years [1].

In Greek conditions, with an irrigated orchard and often heavy soils, Phytophthora at the collar deserves more attention than the Australian literature gives it, and it is separated from the other root rots by the pattern in the field: Phytophthora gives patches where water stands, while the other causes give scattered individual trees. Collar rots in fruit trees generally are analysed in a separate article.

The measures are purely managerial and transfer: transplanting young trees promptly so the root system does not spiral in the pot, mounded rows and drainage at problem points, annual mulching, and monitoring soil moisture with an instrument rather than by estimate [1].

Sources: 1 2 14 19 21

9. Phytoplasmas in declining persimmon: yellowing, reddening and dieback with no finding at the root

This is the newest addition to the list and appears in no manual of the crop. In Mehriz, Yazd province, Iran, that is in semi-arid conditions comparable to the Mediterranean, persimmon trees were found with yellowing, reddening, dieback and general decline [15].

By polymerase chain reaction, from symptomatic trees only, two different phytoplasmas were identified, 'Candidatus Phytoplasma omanense' of the 16SrXXIX group and 'Ca. P. australasiae' of the 16SrII-D subgroup, in some cases as a multiple infection in the same tree. The researchers explicitly call for a systematic survey to establish the extent of the phenomenon [15].

Sources: 15

10. Mealybugs, Planococcus citri and Pseudococcus spp., and the decisive contribution of ants

Mealybug is the pest of greatest practical importance for persimmon, and it is the pest Greek growing has already met: infestation of persimmon fruit by Pseudococcus comstocki has been recorded and is analysed in a separate article. Three species are recorded on persimmon, Planococcus citri, Pseudococcus longispinus and Pseudococcus calceolariae [1], all three present in the Mediterranean. Planococcus citri is also recorded as a significant persimmon pest in Taiwan [14].

The biology of Planococcus citri, as given for Queensland: adult female about 3 mm, covered in white mealy wax, life cycle four to six weeks in summer, with the female laying up to 600 eggs over about a fortnight and hatching in a week [1].

What decides management is not the mealybug but the ants. Ants feed on the honeydew, carry mealybugs from fruit to fruit and drive off their natural enemies. The finding is explicit: high ant densities dramatically reduce parasitism and predation, while low densities appear to have little effect [1].

The technical detail of trunk banding is worth writing down, because it is usually done wrong: the sticky material is not applied to the bark. A band of straight trunk is first wrapped with soft padding 100 mm wide, with a 20 to 30 mm overlap, and the gel goes onto the padding [1]. The bark is then not damaged and the band is easy to renew.

Three natural enemies are recorded, and all are commercially available in Europe [1]: Cryptolaemus montrouzieri, which needs six to eight weeks after release to bring the population under control, Leptomastix dactylopii, which is a parasitoid of Planococcus citri only and will not touch the other species, and Anagyrus, which parasitises first and second instars. The specificity of Leptomastix is the reason species identification comes before any release decision. The biology, temperature requirements and release rates of beneficials are analysed in a separate article, with Greek data.

Sources: 1 14

11. Soft scales, wax scales Ceroplastes spp. and mussel scale: three groups needing different management

The species of immediate Greek relevance is the fig wax scale, Ceroplastes rusci, which attacks both fig and persimmon and has been recorded in Greece. It is analysed in a separate article, which is also where its Greek figures come from.

The other soft scales recorded on persimmon are the same species a Greek grower already knows from olive and citrus.

Sizes and cycles are species biology and transfer. The number of generations and the action thresholds are Australian and are given as an order of magnitude [1].

11.1 Mussel scale: an armoured scale with no honeydew

Mussel scale is an armoured scale and is recorded on persimmon [1]. It differs from everything above in three ways that change management.

• It produces no honeydew. So there is no sooty mould to draw attention and no ants to show the way. Detection comes only from looking at the fruit and the bark.
• The scale cover protects. The waxy cover makes most contact products ineffective at every stage except the crawlers, exactly as with wax scale.
• The damage is commercial. The flesh is not affected, but the fruit is rejected at grading and, for export, at phytosanitary inspection.

The general message of all the scales is that parasitism does the work when it is allowed to. Parasitism rates reaching 90% for one wasp on a wax scale and 85% for another in a particular region are recorded, and in wet weather the entomopathogenic fungus Verticillium lecanii causes up to 90% mortality in green coffee scale [1]. Those rates collapse under broad spectrum sprays and under ants.

Sources: 1

12. Orange spiny whitefly, Aleurocanthus spiniferus: a Union quarantine pest already present in Greece

Aleurocanthus spiniferus is the only species in this article that is simultaneously a quarantine pest, present in Greece and has persimmon among its hosts. It has been on the EPPO A2 list since 1994, transferred in 2009, and is a Union quarantine pest listed in Annex II B of Regulation (EU) 2019/2072 since 2019 [16] [21].

Its European distribution, according to the EPPO database, covers Greece, Italy including Sicily, Croatia, Montenegro, Albania, France including Corsica and Georgia, all with restricted distribution, while in Austria, Belgium and Czechia the species has been eradicated [16]. In Greece its presence was recorded in 2016 on Corfu [17]. In Italy it had appeared earlier, in Apulia.

Field identification is made from the puparium and not from the adult: black, oval, immobile bodies on the underside of the leaf, with characteristic spines, and abundant honeydew with heavy sooty mould below. The species is analysed in a separate article.

Sources: 16 17 21

13. Fruit flies, Ceratitis capitata and Bactrocera dorsalis, and brown marmorated stink bug Halyomorpha halys

13.1 Mediterranean fruit fly, Ceratitis capitata

Persimmon is a host of Ceratitis capitata [1]. The species is analysed in a separate article.

13.2 Oriental fruit fly, Bactrocera dorsalis

Bactrocera dorsalis bears directly on European persimmon growing. In Italy it has been detected since 2022 in Campania, Emilia-Romagna, Lombardy, Trentino and Veneto, with the status "transient, under surveillance, under eradication". In Campania 114 specimens were caught in the infested zone by the end of September 2023, with about 3,300 traps under a national action plan, 1,000 mass trapping traps, and a ban on moving host fruit out of the zone [18]. It is also recorded as a significant persimmon pest in Taiwan [14].

The detail that concerns persimmon: in Emilia-Romagna three males were trapped inside a persimmon orchard, and the fruit sampled there was not found infested [18]. That is, the insect enters the orchard, but infestation of persimmon fruit was not documented in those surveys. This is a useful distinction and should not be inflated in either direction.

13.3 Brown marmorated stink bug, Halyomorpha halys

Halyomorpha halys has an extremely wide host range and is present in Greece. Its position in Greek fruit growing makes it an expected visitor to persimmon, with the typical picture of feeding punctures and sunken deformations under the skin. It is analysed in a separate article.

Sources: 1 14 18

14. Eriophyid mites, thrips, leafhoppers, defoliating moths and earwigs: monitoring and thresholds

Eriophyid mites, with Aceria diospyri on persimmon, usually pass unnoticed. The only figure worth keeping is the speed: from egg to adult in one week under favourable conditions, with several generations a year and overwintering in axillary buds [1].

Thrips come with an admission worth transferring verbatim, because it is rare: there is no spray threshold and no number of thrips has been linked to economic damage, and the presence of thrips does not mean damage will follow, even in large numbers in flowers [1]. Monitoring is by beating branches onto a white surface and with yellow sticky traps.

Leafhoppers carry a threshold of 20% of green twigs infested, with a very useful addition: if more than half of the sampled egg rafts produce parasites, the population can be expected to decline on its own [1].

Defoliating moths justify intervention when defoliation exceeds, or is likely to exceed, 30%, and leaf rollers when more than 5% of flowers or fruit is infested [1]. In Taiwan Spodoptera litura is also recorded as a significant pest [14].

Earwigs, with Forficula auricularia, are the most misread group. They chew the leaf margin and disappear during the day, so the damage is attributed to other causes. They are also predators.

Snails are a Greek problem in fruit trees, and the white Mediterranean snail is analysed in a separate article.

Sources: 1 14

15. Abiotic damage mistaken for disease: herbicide toxicity, sunburn, cracking and physiological fruit drop

In a new crop, where experience is missing, most of the questions reaching an agronomist do not concern pathogens.

15.1 Contact herbicide toxicity, pyraflufen-ethyl

Contact herbicides that act by oxidative destruction of the cell membrane, such as pyraflufen-ethyl, produce, when droplets drift, discrete necrotic spots at the point where each droplet landed. On persimmon the picture is strikingly misleading, because the spots are round and dark and resemble anthracnose or black spot.

Four features separate the toxicity from the pathogen, and none of them needs a laboratory:

• The distribution on the tree. Damage is densest low down, near the height of the spray boom, and thins out upwards. No fungal leaf spot behaves like that.
• The distribution in the block. It follows the row that was sprayed and the wind direction of that day, not the damp spots.
• The timing. Spots appear within a few days of the spray and do not enlarge afterwards. Fungal lesions enlarge and coalesce.
• The absence of progression. No new spots appear on leaves that emerged later.

15.2 Sunburn, cracking, surface scarring and physiological fruit drop

Fruit sunburn. Persimmon holds its fruit on the tree late, often after leaf fall has begun, so the fruit is exposed. The lesion is on the side facing the sun, pale at first and then brown, and has none of the margins that fungal lesions have.

Cracking. An abrupt change in water availability, whether rain after drought or irregular irrigation, splits the skin. The crack then becomes an entry for Alternaria, Penicillium and Rhizopus, so the final picture is rot and the cause is irrigation [10].

Surface scarring. Corky lines from rubbing on a branch or netting, from wind damage to young fruit, or from surface insect feeding. It is a commercial problem, not a pathological one.

Fruit drop after set. In persimmon physiological drop is heavy and is linked to the balance between crop load and growth, to the cultivar and to the pollination regime. Before a pathogen is sought, the physiological cause is ruled out. Cultivar questions are covered in a separate article on Maxim and in an article on Rojo brilliante, and pruning, which also determines canopy aeration, separately.

Sources: 10

16. Differential diagnosis: causes that give almost the same picture, and the feature that separates them

17. Action thresholds, sampling units and the annual monitoring calendar

The table that follows gives sampling unit, frequency and threshold together, that is the entire method and not just a number [1].

Source for the whole table [1]. The months in the original are southern hemisphere and have been rendered as crop stages.

Sources: 1 2 3 4 9 10

18. Exotic persimmon pathogens at risk of introduction into the Mediterranean, and their common entry route

This section is not alarmism. It is the list the Spanish drew up after the circular leaf spot experience, that is by people who have already been surprised once [2].

Sources: 2 14

19. Sources

The numbers in the text refer to the list below.

• [1] State of Queensland, Department of Agriculture and Fisheries (2017). Integrated Pest and Disease Management Manual for Persimmon, 2nd Edition, November 2017. Licensed under Creative Commons Attribution 4.0 International. Source for the biology and symptoms of the diseases and pests, for the action thresholds of Table 2, for the sizes and cycles of the scales, for the natural enemy data, and for eight of the thirteen photographs. Full text read. Images carrying a third party photographer credit were not used.
• [2] Vicent, A., Mira, J.L. and Bassimba, D.D.M. (2018). Fungal diseases of persimmon in semi-arid areas: adaptive strategies and future risks. Acta Horticulturae 1195:127-132. Source for the pathogen's adaptation mechanism to semi-arid conditions, for the ineffectiveness of post-infection sprays, for leaf litter management and the forecasting system, for the persistence of Alternaria inoculum and the three-month period of latent infections, for the root rots and Botryosphaeriaceae in Spain, and for the whole future risks section. Full text read.
• [3] Vicent, A., Bassimba, D.D.M. and Intrigliolo, D. (2011). Effects of temperature, water regime and irrigation system on the release of ascospores of Mycosphaerella nawae. Plant Pathology 60(5):890-908. Source for release beginning at 10 °C and increasing exponentially to 16 °C, for the 1 mm water threshold, and for the dramatic reduction of ascospores under drip irrigation compared with flood. Results read through review [2], not from the original.
• [4] Vicent, A., Bassimba, D.D.M., Hinarejos, C. and Mira, J.L. (2012). Inoculum and disease dynamics of circular leaf spot of persimmon caused by Mycosphaerella nawae under semi-arid conditions. European Journal of Plant Pathology 134(2):289-299. Source for the ascospore release period from late March to mid July peaking in April and May, for the infection period April to June at 12 to 24 °C, and for symptoms appearing 120 to 127 days after full bloom. Results read through review [2], not from the original.
• [5] Berbegal, M., Pérez-Sierra, A., Armengol, J., Park, C.S. and García-Jiménez, J. (2010). First report of circular leaf spot of persimmon caused by Mycosphaerella nawae in Spain. Plant Disease 94(3):374. Source for the first report of circular leaf spot in Spain and for its detection in Valencia in 2008.
• [6] Hassan, O. and Chang, T. (2025). Phylogeny, morphology, epidemiology, and control strategies for Plurivorosphaerella nawae, the causal agent of circular leaf spot in persimmon. Research in Plant Disease 31(1):1-16. Source for the whole Korean column of the comparison table: release period with 96.5% from mid June to mid July, infection range 17 to 24 °C, latent period of 33 to 34 days in May and 11 days in August, 90% of spores within two hours of wetting, and the absence of a resistant cultivar. Full text read.
• [7] EPPO Global Database. Plurivorosphaerella nawae (MYCONA). Source for the valid name and the synonym, and for the fact that the organism is not on the EPPO A1 or A2 lists and that no distribution record is maintained for it.
• [8] Palou, L., Montesinos-Herrero, C., Tarazona, I., Besada, C. and Taberner, V. (2015). Incidence and etiology of postharvest fungal diseases of persimmon (Diospyros kaki Thunb. cv. Rojo Brillante) in Spain. Plant Disease 99(10):1416-1425. Source for the separation of latent and wound pathogens with the species of each, for losses of up to 30% of fruit in Spanish packinghouses, for black spot becoming the main limiting factor after 1-MCP was adopted, and for the absence of approved postharvest fungicides in the European Union. Full text read.
• [9] Kobiler, I., Akerman, M., Huberman, L. and Prusky, D. (2011). Integration of pre- and postharvest treatments for the control of black spot caused by Alternaria alternata in stored persimmon fruit. Postharvest Biology and Technology 59(2):166-171. Source for latent infection in the orchard and symptom development two to three months after entry into storage at 0 °C, and for the difference between 60% and 3% for the preharvest application fourteen days before harvest versus thirty days after fruit set. Full text read.
• [10] Biton, E., Kobiler, I., Feygenberg, O., Yaari, M., Kaplunov, T., Ackerman, M., Friedman, H. and Prusky, D. (2014). The mechanism of differential susceptibility to alternaria black spot, caused by Alternaria alternata, of stem- and bottom-end tissues of persimmon fruit. Postharvest Biology and Technology 94:74-81. Source for colonisation at the stem end rather than the bottom end, for the greater cracked area and reduced chlorophyll there before harvest, and for increased irrigation enlarging the cracked area and the susceptibility to black spot. Full text read.
• [11] International Society for Horticultural Science (2018). Evaluation of short postharvest gaseous treatments for inhibition of Alternaria black spot of persimmon 'Rojo Brillante'. Acta Horticulturae 1195. Source for the 30 to 40% reduction at 40 days at 1 °C with 95 kPa carbon dioxide, for the loss of that reduction by 82 days, and for greater rot severity on treated fruit. Publisher abstract read.
• [12] Moyo, P., Mostert, L., Bester, M. and Halleen, F. (2016). Trunk disease fungi associated with Diospyros kaki in South Africa. Plant Disease 100(12):2383-2393. Source for the list of species isolated from cankers, pruning wounds and dieback, for the confirmation of their pathogenicity, for symptoms appearing in fifteen year old orchards in a Mediterranean climate, for pruning wounds as the main entry route, and for lesion lengths of 30.7 to 65.2 mm with a difference in favour of the Diospyros kaki rootstock. Full text read.
• [13] Zhang, J.-Z. (2008). Anthracnose of persimmon caused by Colletotrichum gloeosporioides in China. The Asian and Australasian Journal of Plant Science and Biotechnology 2(2):50-54. Source for C. gloeosporioides being the major persimmon pathogen in almost all areas of extensive cultivation in China, for overwintering as mycelium in diseased tissue, and for conidia being dispersed by splashing rain. Full text read.
• [14] Duan, C.-H., Chang, C.-M., Su, C.-C., Pan, H.-R. and Wang, C.-C. (2017). Phyllosticta capitalensis causes black spot on persimmon (Diospyros kaki) fruit in Taiwan. Australasian Plant Disease Notes 12:36. Source for the description of circular sunken black spots 1 to 2 mm across on mature fruit and for the list of common persimmon pathogens and pests in Taiwan. Full text read.
• [15] Esmaeilzadeh-Hosseini, S.A., Babaei, G., Mateeti, S.T., Pacini, F. and Bertaccini, A. (2025). Detection and identification of diverse phytoplasmas in declining persimmon plants. Microorganisms 13:645. Source for the symptoms of yellowing, reddening, dieback and decline in persimmon in Iran, and for the identification of the phytoplasmas 'Ca. Phytoplasma omanense' and 'Ca. P. australasiae' in symptomatic trees only. Full text read.
• [16] EPPO Global Database. Aleurocanthus spiniferus (ALECSN), categorisation and world distribution. Source for listing on the EPPO A2 list in 1994 with transfer in 2009, for listing in Annex II B of Regulation (EU) 2019/2072 from 2019, for the European distribution, and for the note that records before 2011 may concern Aleurocanthus camelliae.
• [17] Kapantaidaki, D.E. et al. (2019). Presence of the invasive whitefly Aleurocanthus spiniferus (Hemiptera: Aleyrodidae) in Greece. EPPO Bulletin 49(2). Source for the first record of the species in Greece, on Corfu. Publisher record read.
• [18] EPPO Reporting Service. Update on the situation of Bactrocera dorsalis in Italy. Source for the five Italian regions, for 114 specimens in Campania by the end of September 2023, for the traps of the national plan, for the status "transient, under eradication", and for the three males in a persimmon orchard in Emilia-Romagna with no fruit infestation.
• [19] EPPO Global Database. Ralstonia solanacearum (RALSSL), datasheet. Source for the former name Pseudomonas solanacearum corresponding to today's Ralstonia solanacearum, for listing on the A2 list and in Annex II B, and for the absence of persimmon from the host list.
• [20] Paisiadis, S. (2023). Persimmon: how the new plantings are done, first Producer Group founded in Pella. Agrotypos, 28 November 2023, in Greek. Source for the continuing expansion of the area in Pella, for the founding of the first Producer Group, for the cultivars and for the planting distances. A press account, not a scientific publication.
• [21] Commission Implementing Regulation (EU) 2019/2072. Source for the status of Union quarantine pests and for the fact that the EPPO A1 and A2 lists are not identical with Union quarantine status.
• [22] Greek Ministry of Rural Development and Food. Database of approved plant protection products, in Greek. Source for what is permitted on persimmon in Greece. Approvals are national, valid in Greece only, and they change, so the check is made before every intervention.