Mutsukogane

This document alone dates in the Western calendar

"Fukei No.62" was crossed in 1954 at the Fujisaka Testing Site of the Aomori Prefectural Agricultural Experiment Station, taking "Norin No.22" as the mother and "Towada" as the father; in the winter of the same year the F1 generation was shortened in a glasshouse, and in 1955 the F2 was grown in bulk in the field for seed.

Every historical document this site quotes gives its years in the Shōwa era. Shōwa 16, Shōwa 21, Shōwa 29.

Mutsukogane's document alone uses the Western calendar. 1954, 1955, 1956, 1958, 1959, 1961, 1963. Shōwa never appears once.

Natsuminori's document set the character out as a bulleted list. Yamaseshirazu's set the history out as a list of fields. This time it is the way the years are written.

The shape of a source changes with where and when it was written. Even inside one database nothing is uniform — here is one more instance.

Sent from Aomori to Kagoshima and back

In the winter of the same year the F1 generation was shortened in a glasshouse, and in 1955 the F2 was grown in bulk in the field for seed. In the spring of 1956 the F3 seed was sent to the Rice Breeding Section of the Kagoshima Prefectural Agricultural Experiment Station, where over two years the generations were shortened by direct-sown bulk culture in the nursery bed, advancing from F3 to F6. In 1958 the F6 panicles were moved to the Fujisaka Testing Site and the F7 grown in lines by panicle for line selection.

1954 Aomori, Fujisaka  cross → F1 in a glasshouse
1955 Aomori, Fujisaka  F2 in the field
1956 Kagoshima         F3 seed sent down
1957 Kagoshima         direct-sown nursery beds carry it to F4, F5, F6
1958 Aomori, Fujisaka  F6 panicles brought back; line selection from F7

Aomori → Kagoshima → Aomori. A variety for cold country, fast-forwarded in warm country and brought home.

Nikisakae (Saikai No.75)'s document shows the same trick: "to shorten the breeding period, the F1 was raised at the station's Ibusuki Testing Site from that winter into the following spring" — Ibusuki, in Kagoshima. Two generations a year across prefectural lines, used the same way at two different stations.

More than eight-tenths of the prefecture was mid-maturing

Rice growing in Aomori Prefecture has advanced towards safe, high yields centred on the mid-maturing Towada and Fujiminori, but on the other hand one strongly feels that planting has concentrated too much on mid-maturing varieties. (More than eight-tenths of the whole prefecture.)

More than eight-tenths of the prefecture, mid-maturing.

Leaning on safe, productive varieties brought the cropping season together into one point. Then transplanting and harvest both arrive at once, and hands run short.

With Towada and Fujiminori being a little too early, the breeding of a fine late variety ripening somewhat later has been sought.

To replace its father Towada, it was made with Towada as the father. Its mother Norin No.22 is Koshihikari's mother, which makes Mutsukogane Koshihikari's half sibling.

Its cold tolerance is stronger than "Norin No.17"'s and "Towada"'s, and as a late variety it holds fairly strong resistance

What ripens late meets the cold. Made later, and still more cold-tolerant than its father.