INTRODUCTION

The cultivation and climatic requirements of persimmon have been extensively covered by previous authors.^1-7 These reviews have shown that persimmon can be cultivated over a wide range of climatic environments, from temperate through tropical zones. This review describes the ecophysiology of persimmon and discusses the environmental limitations to production.

Origin and Distribution

Persimmon is a member of the genus Diospyros containing over 400 species,⁸ which occur predominantly in tropical and subtropical environments. Species tend to be evergreen, but several species are deciduous and adapted to warm temperate climates. Diospyros kaki L. is the major commercial species. Other species, D. virginiana L., D. lotus L., D. oleifera Cheng, D. digyna Jacq., and D. blancoi A. DC., are of relatively minor importance.

The mountains of central China are the centre of origin and primary centre of diversity for D. kaki, and Japan is a secondary centre.⁹ The wild form of persimmon, D. kaki var sylvestris Makino grows in mountain areas in central and western China to an altitude of 1150m.¹⁰D. kaki is hexaploid (2n = 90)¹¹ and the wide diversity in fruit shape and form suggest probable alloploid origins.¹² Morphological, geographical and cytological evidence suggests that D. oleifera (syn. D. roxbergia Carriere) is a parent of D. kaki .¹³ The origin of the other parental species is not known but it could be D. hexameria Wu., a species closely related to D. oleifera from southern China that has a ribbed fruit.

Persimmon has been cultivated in China for several thousand years, where over 2000 cultivars have been selected,¹⁴ and was introduced to Japan about 1300 years ago.¹⁵ In Japan two distinct forms have been selected, astringent and non-astringent, which can be further sub-divided into pollination constant and pollination variant types.¹⁰ The pollination constant astringent (PCA) form is the oldest and comprises almost all the Chinese cultivars and several Japanese cultivars. Pollination variant astringent and non-astringent (PVA, PVNA) forms originated in Japan about 1200 years ago and show flesh darkening when pollinated. The flesh darkening reaction is associated with a low ascorbic acid content in the flesh,¹⁶ high polyphenol oxidase activity¹⁷ and ethanol production in seeds.¹⁸ The pollination constant non-astringent (PCNA) persimmon is the most recent form, originating approximately 500 years ago in Japan.¹⁹ It was derived from PCA cultivars, but has a different tannin composition.²⁰ The PCNA form is generally free of astringency at harvest; post-harvest treatment to remove astringency are not required.

Table 1: Climatic Characteristics Of Persimmon-Growing Locations.

The distribution of persimmon to countries outside Asia has occurred within the last 150 years. Commercial cultivation occurs between latitudes 45• north and south of the equator (Table 1). Over one million tonnes of persimmon are produced annually from an area of approximately 235,000 hectares.²¹ The major producers are China, Japan, Brazil, Korea and Italy. Minor producers include Israel, U.S.A., New Zealand, Australia, Spain, Georgia, Egypt and Chile.