多収環境におけるNFT低段栽培トマトの収量と根系の比較解析

摘要

NFT養液栽培において，多収環境(C0_2施用および钿霧冷房）で管理すると慣行栽培に比べて，16品種の平均で収量が40%向上した.年間収量に換算すると，今回調査した品種の内，最高の収量を示した'CF桃太郎J'でも20kg·m~（-2）であり，オランダなどで報告されている収量に到達するには，C0_2施用期間の延長および，湿度制御の適切な導入が必須である.多収環境では根系の活性が高く維持されていたが，NFT低段栽培においては品種間の収量と出液速度との相関は低く，比較的短期の栽培では相対的に根の寄与率は低くなると推察され，多収環境に保つことによって地上部の同化産物を増やすこと等の方がより重要だと考えられる.%The average yield of 16 tomato cultivars was 40% greater under high-yielding conditions (including extension of C0_2 enrichment and appropriate humidity control) than under conventional NFT conditions. The highest-yielding cultivar was CF Momotaro J, which gave 20 kg m~-2 under year-round cultivation. High-yielding environmental controls must be introduced into Japan to give the high tomato yields seen as in the Netherlands. Under low-truss nutrient film technique (short-term cultivation), root activity was significantly higher under high-yielding conditions than that under conventional conditions, but the correlation between yield and bleeding rate on each cultivars was not so high. These results suggest that the contribution of root activity to yield in short-term cultivation was lower than in long-term cultivation on the previous report. Therefore, this suggests that an increase in the amount of matter assimilated is the primary factor associated with high yield in short-term cultivation.