Vergara - 1976 - Physiological and morphological adaptability of ri

RICE PRODIlCTH-TTY IN ("IAlh“i|AT1(-‘ REGIONS OF JAPAN 451
Table 1. Average valuea for 1961-1971 of not production (Pn). number of days from transplanting
to maturity (t), mean crop growth rate tor the same period (mean CGR), and yield
of brown rice in dry matter (Y) at various locations in Japan [Murata and TogarL, 1976].
North Pn t Mean CGR Y
Station latitude Variery 9lm= (S.D.) days g-m-~day-' glml
Akita 39°41 Yoneshiro 1286 i 115 124 10.37 4B3
Miyoshi 1415 x 116 131 10.80 489
Sendai 38'13‘ Fukei 72 1598 z 143 123 13-93 552
Others 1595 i 166 124 12.86 558
Tekada 37°05‘ Honenwase 1365 1 60 1 10 12.40 524
Fulcui" 36°04‘ Manryo 1640 :1: 195 136 12.06 567
Nagano 38°39‘ Honenwase 143B 1 108 112 12.84 527
Manryo 1727 a; B5 12B 13.49 600
Konoru 36°02‘ Tamayodo 1439 i 93 1U? 13-45 492
Nihonbare 1555 1 77 120 12.06 497
Fukuyama 34'30' Manryo 1449 1 71 108 13.42 511
Na katashinsenbon 1507 1 46 119 12 .66 510
Chikugo 33°12‘ Helyoku early season 1631 1 136 127 12.84 555
normal season 1591 i 1B9 113 14.08 564
‘Takada in 1967-68. Fukui in 1959471.
Net production and mean CGR
The highest S-y-‘ear average annual net production. 1,727 g/sq m was attained by
a late-maturing variety’. Manry-"o, at Nagano. a station in a basin with an elevation
of 364m in the mountainous region of Middle Japan‘ The second highest
value, 1,640 g/sq m, was obtained with the same variety at Takada and Fnkui,
stations along the coast of the Japan Sea, nearly equaled by the 1.631 g/sq m
attained by the early season tiflltiywwltru at Chikugo. the southernmost station.
The single-year record high in net production was 1.974 g/sq m attained by
a late-maturing variety’. Kinpa. at Fukui in 1970.
The locational differences in net production were not very large. since even the
lowest value. 1.286 g/sq m. which was tibSBfVBd at Akita. the northernmost
station. is equal to 74.5% of the highest. but quite significant differences did
exist. Although the lowest net production was found at the northemmost
station. no clear general relationship can be found between geographical location
and net production,
On the other hand, the mean CGR which was obtained by dividing net production
by the number of days from transplanting to maturity was highest with
itormal season culture at Chikugo, 14.08 g - sq m ' - day l, followed by 13.49
g - sq m“ ' day" at Nagano and 13.45 g-sq m" - day-l at Konosu. The lowest
value was 10.37 g - sq m-* - dayi-l at Akita. Mean CGR, therefore. seems generally
to increase as the location shifts from north to south. A positive correlation eoeffieicnt
of0.604. significant at 5% level, was found between the mean CGR and
the corresponding mean temperature from transplanting to maturity.
Thus it appears that a considerable part of the locational difference in net
production depends on two factors, the difference in the number of days from
transplanting to maturity and the mean temperature during the same period.
At each station. on the other hand. net production was generally higher in