Effect of rootstocks on the extension of harvest period of cucumber (Cucumis sativus L.) grown in non-renewal hydroponics

The effect of rootstocks in non-renewal solution culture of cucumber (Cucum is sativus L. cv. Shogoin-aonaga-fushinari), on sustaining yield in the lat e harvest period for autumn, spring, and summer crops was investigated. 1. Vegetative growth of 'Shogoin-aonaga-fushinari' plants at the end of the experiment was only slightly affected for the 3 seasons whether they were ungrafted or grafted on seedlings of 'Shogoin-aonaga-fushinari', 'Hokushin' or 'Aodai'. There is no evidence that rootstocks influence vegetative grow th. 2. The number of harvested fruit of 'Shogoin-aonaga-fushinari' in the summe r crop was increased by grafting on the roatstock of 'Hokushin' or 'Aodai'. The weekly number of harvested fruit which decreased in the late harvest p eriod on ungrafted plants was not observed on plants grafted on 'Hokushin' or 'Aodai' seedlings, thereby, extending the harvest season. Thus, the fruit yield in the closed nutrient flow system was sustained for a longer period by grafting 'Shogoin-aonaga-fushinari' on 'Hokushin' or 'Ao dai' seedlings.