The production of high-quality persimmon fruit is critical to sustain and grow the consumer demand in domestic and export markets.
Asia produces most (43%) of the world’s persimmons. Consumers in Asian countries prefer sweeter fruit. In highly competitive and consumer-driven markets, persimmon growers must consistently supply fruit that meets or exceeds consumers’ expectations.
Demand for persimmons in Australia is increasing because of consumer trend for healthier food options, increased immigration from Asian countries and growth in export markets.
Collectively this creates an opportunity for persimmons to become a mainstream product in Australia, says Dr Tahir Khurshid from NSW Department of Primary Industries at Dareton in Far Western NSW.
He says the marketing season is currently as short as three to four months (March-June), due to the heavily reliance on two mainstream varieties ‘Jiro’ and ‘Fuyu’. So, Australia needs access to new varieties to extend the harvest season.
Dr Khurshid said there is a need for a non-astringent variety which matures earlier than ‘Jiro’. Jiro matures in mid-March to early-April in Queensland and mid-April to early-May in NSW, South Australia, Victoria and Western Australia depending on the growing season.
The other variety, ‘Fuyu’, matures later than ‘Jiro’ and is followed by ‘Suruga’, a hybrid of Hanagosho x Okugosho. ‘Suruga’, however, is not widely planted throughout Australia due to its limitations. Therefore, a late maturing variety is needed that should follow ‘Fuyu’. The production and marketing season can be extended for the availability of persimmons in Australia.
Hort Innovation has funded a project ‘National Persimmon Varietal Evaluation Program’ led by Dr Khurshid. Dr Khurshid has 18 years’ experience in evaluating rootstocks and varieties.
One of the main objectives of this funded project is to import early and late maturing varieties to extend the growing persimmon season across Australia. This article will present the current progress relating to the importing of an early maturing variety for the Australian persimmon industry.
Dr Khurshid visited the persimmon industries in Spain and Portugal in 2018 and then the major persimmon producing countries of Japan, South Korea and China in October 2019 (just before the Covid19 outbreak occurred in China in December 2019). In Japan Dr Khurshid negotiated to import the early maturing variety ‘Taishu’.
However, to import a variety from any country is not an easy task due to the strict quarantine requirements in Australia and the cost involved to import and maintain a variety in Australian quarantine. The other confounding issue is the opposite growing seasons in Japan which makes it very difficult to import budwood or seeds from countries of Northern hemisphere.
Import of ‘Taishu’ into Australia
‘Taishu’ was imported in November 2020 for the first time as budwood from Miyazaki University, Japan. The budwood was securely placed with ice packs in a polystyrene box to reduce the probability of disease development and insure its entry into Australia.
The post entry quarantine services group, Department of Agriculture and Water Resources in Australia (now DAWE) grafted the budwood to the Diospyros kaki rootstocks on arrival and put the budwood in a cool room to induce dormancy. This allowed them to successfully graft four trees after the completion of dormancy. The trees were healthy and grew in the Department’s post entry quarantine services group.
The trees have now been released from quarantine, and they are at Dareton as ‘Taishu’ mother trees. The budwood will be produced for further multiplication and to establish trials plantations across Australia. This can take up to 3–4 years.
Characteristics of ‘Taishu’
‘Taishu’ is a Japanese persimmon (Diospyros kaki Thumb) that was released by the Persimmon and Grape Research Centre of the National Institute of Fruit Tree Science, Akitsu, Higashi-Hiroshima, Japan in 1994. Taishu was registered in Japan in 1995.
In Kagwa prefecture, it is mainly cultivated in Ayagawa town and Takamatsu city. In some production areas of Kagwa prefecture the variety is grown for its early production and shipped as ‘blue’ persimmon for their refreshing sweetness and texture.
The fruit is distinguished by its large size, pollination constant non-astringent type (PCNA), and excellent eating quality. ‘Taishu’ resulted from the cross ‘Fuyu’ x ‘II iG' made in 1977. ‘II iG' is a PCNA selection, whose ancestors are ‘Jiro’, Hanagosho’, and ‘Okugosho’. ‘Taishu’ was primarily selected at Akitsu in 1984 and has been tested as a clonal selection at 31 locations in 29 prefectures under the fourth persimmon regional trials initiated in 1977.
‘Taishu’ fruit is roundish flat in shape, weighing an average of 320g (1.3 times larger than ‘Fuyu’), ripens in early to late October in Japan and South Korea, which equates to mid-April to early May in Australia. Larger fruit size and high sugar content are the main characteristics of interest for this variety.
The fruit is also rich and very juicy compared to other non-astringent persimmons such a ‘Jiro’ and ‘Fuyu’. Total soluble solid content in the juice is 17.7% (1.7% higher than ‘Fuyu’). The skin of the fruit is a light orange coloured in Japan; however, Dr Khurshid assumes that it will have better and deeper colour, particularly in southern parts of Australia. The fruit has slight cracking habit at the calyx end. ‘Taishu’ has a shelf life about two weeks longer than ‘Fuyu’.
‘Taishu’ is adaptable to similar production areas as ‘Fuyu’. The tree is moderately vigorous, and intermediate between upright and spreading type in shape. It produces female and male flowers. Its shoots produce male flowers quite easily, leading to the reduction of female flowers and it will be important to produce vigorous shoots constantly by crop management, because vigorous shoots produce female flowers.
Dr Khurshid said ‘Taishu’ variety will be included for wider planation as non-astringent variety for the Australian persimmon industry within next five years.