제주 토양유형이 '제시골드' 키위 과실의 품질에 미치는 영향

Kiwifruit Quality of 'Jecy Gold' as Affected by Soil Types in Jeju Island

동일한 무가온 하우스 내에서 화산회토양(흑색, 농암갈색) 및 비화산회토양(암갈색)에 재배되고 있는 5년생 참다래 '제시골드'(Actinidia chinensis cv. Jecy Gold) 과실의 품질에 미치는 영향을 토양유형에 따라 비교하였다. 토양유형별 토양수분포텐셜은 암갈색 비화산회토양이 가장 낮았다. 개화 후 과실 종경의 비대는 토양에 따른 차이를 나타내지 않았고, 횡경비대는 암갈색 비화산회토양이 흑색 및 농암갈색 화산회토양보다 작은 경향이었다. 과실의 당도는 개화 후 140일까지는 차이가 없었으나, 140일 이후에는 암갈색 비화산회토양이 흑색 및 농암갈색 화산회토양보다 높았다. 수확 후 과실의 산함량 및 경도는 토양유형에 따라 차이가 없었다. 과즙의 과당, 포도당 및 자당함량은 각각 암갈색 토양이 $4.45{\pm}2.08$, $5.43{\pm}1.13$, 및 $2.40{\pm}0.40%$, 흑색 토양이 $2.51{\pm}0.55$, $3.53{\pm}0.86$ 및 $0.80{\pm}0.33%$, 농암갈색 토양이 $2.55{\pm}0.47$, $3.53{\pm}0.73$ 및 $0.73{\pm}0.38%$ 이었다. 따라서 과실의 당도는 토양특성에 따라 영향을 받는다. 이러한 원인은 비화산회토양인 암갈색 토양이 화산회토양인 흑색 및 농암갈색 토양보다 토양수분 보유능력이 낮기 때문으로 판단된다.

Soil types for cultivated crops are approximately compose of volcanic ash soils for black(21%) and dark brown soils(41%), and non-volcanic ash soil of red-yellow soil(17%) in Jeju Island. The effects of these soils on fruit qualities of kiwifruit 'Jecy Gold'(Actinidia chinensis cv. Jecy Gold) were investigated in non-heating plastic house. Soil moisture potential was the lowest in the red-yellow soil during fruit growth. However, transverse diameter of fruit in the red-yellow soil was tends to be smaller than in volcanic ash soils, but longitudinal length of fruit was not shown difference by soil types during fruit maturation. Soluble solids in fruit was not differed by soil types until 140 days after of anthesis, after that the red-yellow soil was the highest. No difference on acid contents and hardness of fruit by soil types. Fructose, glucose and sucrose contents in harvested fruit were $4.45{\pm}2.08$, $5.43{\pm}1.13$, and $2.40{\pm}0.40%$ for the red-yellow soil, $2.51{\pm}0.55$, $3.52{\pm}0.86$, and $0.79{\pm}0.33%$ for the black soil and $2.54{\pm}0.47$, $3.52{\pm}0.73$, and $0.73{\pm}0.38%$ for the dark brown soil, respectively. These results show that soluble solid and free sugars in fruit were affected by soil types. It is estimated that soil moisture was rapidly drought in the red-yellow soil of non-volcanic ash soil than in the black and dark brown soils of volcanic ash soil.