One cross, several varieties

One cross does not yield one line. Split the hybrid population, send it to different places and select it separately, and it becomes different varieties.

Setting the historical documents against one another, four groups can be confirmed as coming from a single cross.

Cross	Year	Place	What came out
Norin No.22 × Norin No.1	1944	—	eleven lines (out of the same cross)
Kinki No.35 × Kinki No.34	1941	Konosu Testing Site	Koganenami (Etsunan No.5), Yaeho (San'in No.47)
Norin No.22 × Norin No.14	1946	Konosu Testing Site	Wakasa (Etsunan No.15), Yamahonami (Etsunan No.18)
Chukyoasahi × Norin No.22	1945	Tokai Branch	Chiyohikari (Tokai No.6), Yamabiko (Tokai No.7)

In every case, two or more historical documents agree on the year, the place, the mother and the father.

They divide in three different ways

The prefectures divide

Koganenami and Yaeho — the seed of one cross went to two prefectures.

	Route	Adopting prefecture
Etsunan No.5 Koganenami	Niigata → Fukui	Fukui
San'in No.47 Yaeho	Shimane → Izumo → Shimane	Shimane

Different places of selection, and the documents write different suitable ground: Koganenami "the flat country of Kanto-Tosan and the mid-mountains from Fukui southwards", Yaeho "a late variety for the mid-mountains generally and the mountain districts".

The eleven lines out of Koshihikari's own cross are the same shape — split between Fukui (Etsunan No.14 and No.17) and Tohoku (Ou No.224 and No.225), and fixed at different generations.

The maturity divides, in the same prefecture

Wakasa and Yamahonami are different. Even the route was the same — crossed at Konosu, handed to Izumo, taken over by Fukui the next year.

And still what came out divided.

	Maturity
Etsunan No.15 Wakasa	early
Etsunan No.18 Yamahonami	late-mid

One lot of seed, one place of selection, and the maturity split. The selector is pulling different things out of a single population.

The line numbers run consecutively

Chiyohikari and Yamabiko are Tokai No.6 and Tokai No.7 — two lines out of one cross, given consecutive line names.

The two documents agree on the year (1945), the place (the Tokai Branch), the mother (Chukyoasahi) and the father (Norin No.22), and on the move afterwards (the Anjo Agricultural Improvement Laboratory). On this site the two relations carry the same cross identifier.

The same cross combination is not the same cross

Confuse these and you will get it wrong.

Transcribing the named rows from the listings of Koshihikari's two parents gives fourteen groups that share a cross combination, holding forty varieties between them.

Count	Cross combination	Varieties
7	Shuho/Norin No.22	万代錦, 若葉, 若葉4号, 早生若葉, うこん錦, 黄金錦, ほまれ錦
5	Norin No.22/Norin No.1	Koshihikari, Honenwase, Hatsunishiki, Yamasenishiki, Koshijiwase
4	Ou No.189/Norin No.1	玉陸奥, 豊栄, 紅錦, 岩木
3	Ban No.33/Norin No.1	Paddy Rice Norin No.50, 新3号, 新4号
3	Norin No.22/Towada	Mutsukogane, でわみのり, 601-1
2	Kinki No.35/Kinki No.34	Koganenami, Yaeho
2	Norin No.22/Norin No.14	Wakasa, Yamahonami
2	Chukyoasahi/Norin No.22	Chiyohikari, Yamabiko
2	Ou No.187/Norin No.1	Obakowase, 猪苗代1号
2	Bozu No.2/Norin No.1	早潮, 早汐
2	Norin No.1/Norin No.15	1718, 暁
2	Futaba/Kinki No.34	双近4号, 綾錦
2	Norin No.22/Shin No.4	越栄, 越かおり
2	Norin No.22/Fujisaka No.5	しなのひかり, 奈系212

The Japanese names are left as they stand for the varieties this site does not hold: no reading for them has been confirmed in a source, and this site does not invent one.

Of these, only the four groups above are confirmed as one cross. For the rest, all that is known is that someone crossed the same pair of parents.

There is a clear reason not to treat them as the same. Harukaze (Kanto No.74) has Norin No.23 as its mother and Norin No.22 as its father — the same pair as Koganenami and Yaeho. But its document gives a different year and a different place.

	Year of cross	Place
Koganenami, Yaeho	1941	Konosu Testing Site
Harukaze	1954	Kanto-Tosan Agricultural Experiment Station

A separate cross, thirteen years later, somewhere else. Treat a shared notation as a shared cross and this would be counted as one.

What this site therefore does

• A shared cross identifier is given only where two or more documents agree on year, place, mother and father. A matching cross notation is not a basis for it
• One cross has one year. If siblings' documents give different years, that is recorded as a disagreement between sources and the data is kept to one
• Where a sibling's document gives the mother and father in words, that assertion may be used, because it is not an inference from convention — and the basis is written on the page (Koshijiwase is the example)

Every named row is transcribed at Sharing one parent — every named row.