Miyoshi

Miyoshi is one of the first fifteen tea cultivars Japan’s Ministry of Agriculture and Forestry ever registered, named and numbered alongside Yabukita in October 1953 as Cha Norin No. 3. Like Yabukita it began as an individual picked out of seed-grown stock, but its parent material was Uji-strain (Kyoto) zairai rather than Shizuoka zairai, and the selection happened nowhere near Uji: the seed was sown at the Ministry’s tea division in Nishigahara, Tokyo, and the chosen line was carried forward at the government’s tea experiment station, based at Kanaya, Shizuoka by the time of registration. It was released as an ordinary sencha cultivar recommended for Kyushu, Shikoku and the prefectures near Shizuoka — never for its own Uji homeland. Unlike Yabukita, it never found scale: it is essentially absent from current cultivar literature, and the only recent trace of it this research found is a living plant in the national germplasm orchard at Makurazaki, measured for a 2011 study of leaf-blade angle.

Lineage

• Uji-strain (宇治種) zairai seedling — an individual selected from seed sown at the Ministry of Agriculture and Commerce’s tea manufacturing division in Nishigahara, Tokyo, using Uji (Kyoto) native stock; not a controlled cross, so it has no recorded pollen parent.

Miyoshi, whose own old strain name was 国茶U15号, was one of three Uji-strain Nishigahara selections registered in the same 1953 cohort: the others are Asatsuyu (Cha Norin No. 2, old strain name 国茶U14号) for premium sencha, and Tamamidori (Cha Norin No. 4, old strain name 国茶U17号) for tamaryokucha. All three were grown from Uji zairai seedlings sown at the same Nishigahara facility and carried forward at the national tea experiment station. They were not the only Uji-derived entries in that round — the release paper records Sayamamidori (Cha Norin No. 5) as a Uji-strain seedling too, selected in 1935 and developed in Saitama rather than at Nishigahara. This is a different lineage from the batch that made Uji’s own reputation — Asahi, Samidori, Gokou and Uji-hikari were selected a year later, in 1954, by the Kyoto Prefectural Tea Research Institute itself, from zairai actually grown in Uji. Miyoshi’s Uji ancestry is real but institutionally once removed from Uji: the seed travelled to Tokyo before anyone selected from it. No descendants of Miyoshi are recorded in any source consulted for this record.

History

The seedlings from which Miyoshi was chosen were sown from Uji-strain (宇治種) seed at the Ministry of Agriculture and Commerce’s Agricultural Experiment Station, tea manufacturing division, in Nishigahara, Tokyo; neither the sowing date nor the exact date of selection is given in the source. What is dated is what happened next: in Taisho 10 (1921) the selected individual was transplanted to the Ministry of Agriculture and Forestry’s tea experiment station, and it was established as a fixed line in Showa 19 (1944). By the time of registration in 1953, the registry table places its breeding station at Kanaya, Shizuoka — the government’s national tea research site, forerunner of NARO’s present-day Institute of Fruit Tree and Tea Science (果樹茶業研究部門).

That registration, in Showa 28 (1953), was Japan’s first tea cultivar registration round of any kind. The Ministry of Agriculture and Forestry named and registered fifteen tea varieties at once — ten for green tea (eight sencha, one tamaryokucha, one kamairicha) and five for black tea — most of which, the release notice says, were already fairly widely grown before the paperwork caught up with them. Miyoshi was Cha Norin No. 3 in that list, alongside Benihomare (No. 1), Asatsuyu (No. 2), Tamamidori (No. 4), Sayamamidori (No. 5) and Yabukita (No. 6). The event was reported in “茶の品種登録と命名” (Registered Tea Varieties), 茶業研究報告 (Tea Research Journal) No. 2, published October 1953 — the second issue of a journal that had itself begun publication only that same year. The stated naming rationale for Miyoshi is “種子の遺伝的純度が高く、実生繁殖に適する”: its seed’s genetic purity is high, which suits it to propagation by seed.

That rationale is worth dwelling on, because it is plausibly why Miyoshi never amounted to much. In 1953 a large share of Japan’s tea was still grown from seed, where every plant in a field is a genetically distinct individual — so a line whose seedlings bred reasonably true to type, as the paper says Miyoshi’s did, was a real asset. But the industry-wide shift that carried Yabukita to dominance over the following decades was the opposite: propagation by cutting, which turns every planted bush into an identical clone and makes an individual line’s seed purity irrelevant. Once cuttings became standard, the specific virtue Miyoshi was registered for had nowhere left to matter.

No later characteristics bulletins or cultivation-area figures for Miyoshi were found in this research. It does not appear on Kyoto Prefecture’s Uji cultivar trade-body pages, in Japanese Wikipedia’s list of roughly seventy current tea cultivars, or in NARO’s national tea cultivar handbook (which covers only state-bred varieties from the mid-2000s onward); My Japanese Green Tea’s cultivar list carries it, but only as a name with its registration year and tea type. The one substantive later record found is a 2011 育種学研究 paper by Tanaka Jun’ichi on leaf-blade angle and yield, which measured Miyoshi — leaf-blade angle 33.8 degrees, below the 39.1-degree mean of the seventy entries measured — among the cultivars held in the national germplasm orchard at Makurazaki, surveyed in the winters of 2008 and 2009. That establishes that the cultivar was still alive in the national collection at that point; whether any commercial Miyoshi plantings survive is not established one way or the other by this research.

Characteristics

The 1953 registration paper classes Miyoshi as 中生種 — medium, or mid-season, budding — the same broad class as Yabukita, though no source gives a day-count relative to Yabukita, the convention this collection otherwise uses. Growth habit is upright (樹姿直立) with strong vigour (樹勢強); the leaves are long-elliptical and green (葉形長楕円形で緑色); yield is rated high (収量多く). The trait the release paper foregrounds is high fruit-set (結実性大) combined with high genetic purity when grown from seed, which together made Miyoshi well suited to propagation by seed rather than by cutting. As tea, it is recorded only as making a good ordinary sencha (普通煎茶として品質良好), recommended for Kyushu, Shikoku and the prefectures near Shizuoka.

Beyond that bare 収量多く, no yield figure is given, and no disease resistance or cold hardiness rating at all is given for Miyoshi specifically — unlike several of its 1953 cohort-mates, whose entries in the same release paper do note such traits (Tamamidori’s cold hardiness and disease susceptibility, for instance, are both stated). Nothing is invented here to fill that gap. Given how completely the industry moved away from seed propagation in the decades after 1953, the one trait Miyoshi was registered for stopped being worth anything, which is a plausible explanation for why, of the fifteen cultivars in Japan’s first registration round, it is one of the very few to have left almost no trace in the later record.