Yamakogane

Fixed across four places

"Etsunan No.12" was crossed in 1941 at the Konosu Testing Site of the Ministry of Agriculture and Forestry Agricultural Experiment Station, taking "Kinki No.34" (Norin No.22) as the mother and "Kinki No.33" as the father; in 1944 the F3 seed was received at the Ministry's designated paddy rice breeding trial site in the Niigata Prefectural Agricultural Experiment Station, from 1947 selection and fixing were pursued at the Ministry's Nagaoka Agricultural Improvement Laboratory, in 1950 the F9 seed was received at the Ministry's Fukui Agricultural Improvement Laboratory, and in 1951, on transfer to the Ministry's designated trial at the Fukui Prefectural Agricultural Experiment Station, it was given the line name "Etsunan No.12" and distributed to the relevant prefectures and others while regional suitability was examined. Kyoto adopted it as a semi-recommended variety from 1955 and Fukui as a recommended variety from 1956. In 1956 it stands at F15.

One sentence names five places.

Konosu (the cross) → Niigata (F3) → Nagaoka (from F6) → Fukui (F9) → Fukui Prefectural (from F10). The cross was in 1941; the fixing report is from 1956, at F15.

Fifteen years, four places. Long even beside Koshihikari's nine years to the line name Etsunan No.17.

"Kinki No.34" (Norin No.22)

Look at how the mother is written.

taking "Kinki No.34" (Norin No.22) as the mother

The Norin number is added in brackets after the line name. Paddy Rice Norin No.22 has no historical document and no page of its own here, but this one line confirms that Kinki No.34 is Norin No.22.

That is Koshihikari's mother. So Yamakogane is Koshihikari's half sibling.

It took after its mother, defects included

Its habit resembles Norin No.22

Its lodging resistance, like Norin No.22's, is weak.

The shape of the plant and the tendency to fall over, both from the mother. Resemblance is not only good news.

Having said that, the document proposes how to use it.

Broadly, its productivity is high under low fertiliser, dense planting and late planting, while on fertile fields and in heavily fertilised plots losses from lodging are large.

Cut the fertiliser and plant densely and it yields. Put it on rich land and it falls over and costs you. If the variety cannot be changed, change the field you put it in.