QUALITY OF CUCUMBER FRUIT AS AFFECTED BY ROOTSTOCK

Several quality attributes of cucumber fruits grown in the spring and fall and from plants grafted onto different rootstocks were compared. The acidity of spring-grown cucumbers was highest in fruits from the 'Andong' rootstock followed by fruits from the 'Heukjong' rootstock and from intact cucumber plants. Electric conductivity (EC), an indication of the total mineral concentration, was highest in fruit juice from intact plants. In contrast, with fall-grown cucumbers, the EC was higher in fruits from plants grafted onto 'Heukjong'. The soluble solids content and sugar content of fall-grown cucumbers were higher in intact plants as compared to those from the 'Heukjong' rootstock. This coincided with the results obtained with spring-grown cucumbers. Glucose was the major sugar in cucumber fruits; 70-100% higher in concentration than fructose. The fructose content was highest in fruits from intact plants and lowest in fruit from the 'Heukjong' rootstock. On the basis of only the fructose content, the sweetness of fruits from the 'Heukjong' rootstock was about 72% of that of fruit from intact cucumbers. Fruit juice from the 'Andong' rootstock contained almost an equal amount of fructose as the juice from intact cucumbers. This clearly indicates the significance of rootstocks on sweetness. Sucrose was not detected in cucumber fruit juice.