INTRODUCTION TO JAPANESE TEA PLANT VARIETIES: CULTIVARS

In 1953 the Japanese tea cultivar registration system, administered by the Ministry of Agriculture, Forestry and Fisheries (MAFF), was established and tea plant varieties were for the first time officially recognized and listed for proper nation wide use. In the 1960s the government developed and established a pragmatic standard for reproducing cultivars from cuttings, and by the 1970 years the majority of newly exploited or replanted tea gardens made use of cultivar cuttings.

It is in this movement that in a major tea region as Shizuoka the largest transformation of tea gardens, shifting from native- or seed-grown bushes to the growth of Yabukita cultivar plants can be witnessed in the period between 1975 and 1980. In succession, this development rapidly spread throughout the whole of Japan, resulting in the implementation of the Yabukita species at 77% of contemporary tea farms as a whole, and at 83% of all tea farms that employ tea bushes of any registered tea plant variety At present, the MAFF has registered 62 cultivars that are especially suitable for tea manufacturing throughout Japan.

Specifications of tea plant varieties

For the most basic division, tea cultivars are divided into 4 classes; one for each specific group of tea species – sencha, gyokuro and tencha, kamairicha, and black tea – that are being produced in Japan. Each group has its specific characteristics for the outcome of the tea, and therefore cultivars are at first instance divided into these groups in accordance with their aptitude to produce the most desirable outcome for that variety of tea.

To further specify, the cultivars that are considered suitable for the manufacturing of sencha are selected based on the prospect of a delicious sencha fragrance. Cultivars that are employed for the cultivation of gyokuro and tencha are selected with a focus on the bush’s resistance to darkness since these plants tend to reside under dense shades during the most important period of their growth. In addition, these bushes must produce a deeply dark leaf to match the desired appearance of both prestigious brands. The anticipation for kamairicha cultivars is the capacity to bring about a fragrant aroma through pan firing. And, black tea cultivars are best when the amounts of catechin in the leaf are high, and when they possess capacities to bring about a strong flavor and fragrance through fermentation.

Development of cultivars

But cultivars do not come about naturally. Cultivars are bred at national research centers where each plant undergoes a rigorous set of tests and evaluations to estimate its capacity as a preferred bush for either one of above-mentioned categories. The evaluation may take years to discover a species that matches the desirable criteria to register as a distinguished variety. Such tests are commonly conducted in six stages of which the final stage is the official registration with the MAFF registration body of tea cultivars.

Tea plant variety selection

Initially cultivars with favorable attributes were selected from a tea garden of seed-grown bushes. However, contemporarily many tea plant varieties have already been brought to existence, and new cultivars aren’t simply singled out, but the practice has come to include methods of artificial breeding bushes by crossbreeding and cross-fertilizing tea seeds of exceptional lineages with notable form and traits. The seeds obtained are then planted and cultivated to become full-grown tea bushes from which a small amount of tealeaf can be obtained and is processed in small amounts as green tea. This initial batch of tea is then sampled and analyzed through tasting.

Testing the selected bushes

From the bushes that have proven worthy during the initial tasting diagnosis cuttings are taken from which seedlings are produced. These seedlings are during their initial growth then tested for their competence during vegetative reproduction. Successively, the seedlings that have passed the tests are planted in a tea garden where they are tested for their characteristics during development as a mature tea bush. Finally, before deciding if any of the bushes that have passed all the tests are worthy for registration, cutting seedlings of the selected candidates are submitted to the primary research centrums in tea-manufacturing areas throughout Japan to further test their qualities in correspondence to the respective regional weather- and environmental conditions. Should the bushes demonstrate the petitioned personality, only then are they enlisted for nationwide recognition as a tea cultivar through registration with the tea cultivar registration system.

The 6 stages of tea plant variety selection and registration

Tea plant variety indicators

Although the sought complexions of tea plant varieties may vary for each region or purpose they are being bred for, the elements that are taken in consideration during screening are similar for most varietals. During the six stages described above cultivars are tested for the following areas. Regarding cultivation and farm management, the bushes are tested for the tree’s form [樹姿; jushi], stretch [株張り; kabuhari], and potency [樹勢; jusei]. The designations for the tree’s form are divided into ‘an open stretch’ [開張; kaichō], ‘intermediary shape’ [中間; chūkan], and ‘perpendicular’ [直立; chokuritsu]. The bush’s stretch is marked ‘narrow’, ‘intermediary’, or ‘wide’, and its potency is either ‘weak’, ‘intermediary’, or ‘strong’.

The plants are also tested for strength, weakness or averageness in enduring cold and withstanding damage through frostbite, in addition to a variety of common bugs and diseases. Since the focus on the spring harvest in Japan is strongest, bushes are also tested on the rapidity with which they awaken from their hibernation, produce young buds and become ready for harvest. The most common system is devised on the threefold ‘speedy-’ [早生; sōsei], ‘seasonal-’ [中生; chūsei], and ‘tardy-’ [晩生; bansei] growers. But more in-depth records take the yabukita cultivar as the criterion to determine the estimated amount of days the examinee is harvest ready prior to, or after this yardstick cultivar. The differences can range from one or two days to a period of over 10 days. Also a matter of scrutiny for the producer is the yield of each respective cultivar, which is also measured in terms of ‘scarce’, ‘average’, and ‘good’, with reference taken from the yabukita species, which is an average cultivar in all areas.

Final tasting assessment

Finally the teas produced from the examinees are subjected to comprehensive tasting with assessment of their qualities in 7 areas, graded on a scale of 5/5. The tested traits are ‘astringency’, ‘umami’, ‘bitterness’, ‘sweetness’, ‘aroma’, ‘liquor color’, ‘luster’ (of the dry leaf), and ‘appearance’ (also of the dry leaf). Based on this observation, it is decided for which type of tea the cultivar is suited. While some cultivars are only suited for the manufacturing of one type only – for example black tea cultivars, – other species may be versatile and possess an appeal for the manufacturing of any type of tea. These judgments are regularly complemented by comments that further specify the traits or points of caution for each individual cultivar.

To summarize, of each cultivar it is known what the bush, and the leaf looks like and how they grow; what the manufacturer may expect from the plant as to growth and yield; how well the bush grows under certain conditions; and how it lends itself to the manufacturing of a certain type of tea and what may be expected as the outcome of the taste. It are these indicators that a tea farmer takes into consideration when he plans to exploit new farmland, or replant a garden that is growing old.