Effects and Mechanisms of Oil Cakes on the Growth of Cucumber (Cucumis sativus L. ) Under Continuous

Fxperiments on the effect of soil amendment with rape (Brassica chinensis L. ) seed cake, cot-ton (Gossypium hirsutum L. ) seed or sesame (Sesamum indieum L. ) seed cake on the growth of cucumberseedlings under a continuous cropping system were conducted in a greenhouse environment. The results indica-ted that two applications of sesame seed cake (0.1 and 0.5 %, w/w) increased the growth of cucumber, but therape oil cake showed a negative effect at a rate of 1.5% (w/w). The sesame seed cake was separated into four fractious(Ⅰ, Ⅱ, Ⅲ and Ⅳ) according to the polarity, and all four fractious had a positive effect on the growth of cucumbers un-der a continuous cropping system. Fraction number Ⅲii was isolated into 25 proportions by silicon column, and only ole-ic acid, palmitic acid and octadecanoic acid were identified in proportion 10 by GC-MS in which 93.3% was oleic acidand palmitic acid. The oleic acid had a significant and positive effect on cucumber growth under salt stress at the level30 mmol and showed slight resistance to several pathogenic fungi.