　ワセウンシュウの高うねマルチ栽培園における根域制限方法の違いが樹の生育，収量，果実品質に及ぼす影響を樹齢14年生まで経時的に調査した。うねの底面幅1.0m，高さ0.5m， 1樹当たりの土量 750Ｌの高うねマルチ栽培では，うね外への根の発生は少なく，根群は深さ20～40cmに集中した。樹冠容積は根域制限の有無にかかわらず慣行栽培に比べて拡大が抑制され， 1樹当たり収量は少ないが，樹冠容積当たり収量は同等もしくは増加傾向となった。樹齢 8年生には樹冠容積，収量とも安定化した成園状態に達した。うねの底面に不透水シートを処理することにより高糖度な果実を生産することが可能となった。

　Effects of Root-restriction on Tree Growth, Yield and Fruit Quality of Wase Satsuma Mandarin in High Ridge Cultivation with Mulching. MATSUMOTO Kazunori,　Daijiro YAHATA, Kosaku USHIJIMA and Minoru KUWAHARA (Fukuoka Agricultural Research Center, Chikushino, Fukuoka 8188549, Japan) Bull. Fukuoka Agric. Res. Cent. 25:65-70 (2006)

　The effects of root restriction on tree growth, yield and fruit quality of Wase Satsuma mandarins in high ridge cultivation with mulching were investigated until the trees became 14 years old. The height and the width measurement at the base of the ridges in the high ridge cultivation was 50×100cm.　The volume of the trees under the high ridge cultivation was smaller than for trees grown by conventional cultivation. But the yield per tree volume was equal to those of conventional cultivation or higher. The growth volume and fruit yield under high ridge cultivation became stable once the trees reached 8 years old. Higher Brix readings were observed in the fruits harvested from high ridge cultivation with impermeable sheets applied at the bottom of the ridges.