報告書番号

V09039

タイトル（和文）

アブラギリ、シナアブラギリおよびカントンアブラギリの油脂生産量の推定

タイトル（英文）

Estimation of seed oil yields of Vernicia cordata, Vernicia fordii and Vernicia montana around Japan

概要 （図表や脚注は「報告書全文」に掲載しております）

国内13ヶ所のアブラギリ属の生育地を選定し、3種の果実量・種子量を2ヶ年にわたり調査し、自然条件下における油脂生産性を評価した。1本あたりの油脂生産量はアブラギリでは0.005～2.0kg/年、シナアブラギリでは0.004～1.9kg/年であった。カントンアブラギリの1本あたりの油脂生産量の上位の値は他の2種より2桁低かった。また、雌花序率50％以上のアブラギリでは樹齢や胸高直径と油脂生産量との間に正の比例関係が認められた。シナアブラギリでは、静岡・京都・岡山で樹齢や胸高直径と油脂生産量との間に正の比例関係が認められた。植栽した場合の30年生までの単位面積あたりの油脂生産量を試算したところ、アブラギリの油脂生産量は30年生で180kg/ha/年に達した。一方、シナアブラギリでは15年生で400kg/ha/年となり、以降油脂生産量増加は頭打ちとなった。以上のことから、アブラギリ属3種のうち、油脂生産性の高い樹種としてシナアブラギリが有望と考えられた。

概要 （英文）

The seed oil productions of Vernicia cordata (Thunb.) Airy Shaw, Vernicia fordii (Hemsl.) Airy Shaw and Vernicia montana Lour. were investigated by field survey around Japan. The survey was carried out from 2007 to 2008 at four areas for V.cordata, at eight areas/sites for V.fordii and one area for V.montana.
V.cordata and V.fordii began bearing fruit at 7-year and 5-year old respectively, but on V.montana the beginning age of fruit bearing could not be found by lack of juveniles.
In 2007, the oil yields per tree of V.cordata ranged 0.007-2.6 kg in Chiba, 0.05-1.1 kg in Fukui, 0.015-2.4 kg in Shimane and 0.003-1.4 kg in Yaku Is. V.fordii trees yielded oils at 0.08-0.8 kg in Tokyo, 0.2-0.9 kg in Shizuoka, 0.5-1.8 kg in Kyoto, 0.8-1.7 kg in Osaka, 0.002-0.4 kg in Hyogo, 0.006-0.45 kg in Okayama and 0.05-0.2 kg in Yamaguchi. The highest yields were found in Chiba for V.cordata and in Kyoto for V.fordii. The yield of V.montana in Okinawa was a tenth to a hundredth of the values of the other two species.
Significant positive correlations were found on V.cordata between the tree age in Chiba and Shimane or the diameter at breast height in four areas and the oil yield per tree. V.cordata trees were divided into two groups by the relative number of inflorescence with female flowers to total in individual tress: relative female inflorescence under 50% and at or above 50%, and re-analyzed the correlations. Much better positive correlations were found on V.cordata with relative female inflorescence at or above 50% in four areas between the tree age or the diameter at breast height and the oil yield per tree . On V.fordii, significant positive correlations were found between the tree age, the tree height or the diameter at breast height in Shizuoka, Kyoto and Okayama and the oil yield per tree. No significant correlation was found between the tree age or the tree size on V.montana in Okinawa.
The oil yields per hectare were calculated using the fitted equations of the oil yield per tree against the diameter at breast height, those of the diameter at breast height against the tree age, and the cited planting density (105 trees/ha for V.cordata or 216 trees/ha for V.fordii). The oil yield could be reached at 180 kg/ha at 30-year old on V.cordata, while saturated over 15-year old V.fordii at 400 kg/ha.

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