Effects of supplemental UV-C and blue light at night on the control of cucumber disease and the growth

In order to find the effect of supplemental light at night on the control of cucumber disease and the growth, cucumber variety Jin you 35 was used as experimental materials, by the method of supplementing UV-C (253.7 nm), blue light (460 nm), blue light/UV-C composite light at night, four treatments including: UV-C, blue light, blue light/UV-C and no lighting (CK), to explore the effect of different light on the control of cucumber diseases and growing development in greenhouse. The results showed that the control effect of powdery mildew in cucumber was 96.01% under the UV-C treatment, and the control effects at the blue light and blue light/UV-C were not obvious compared with CK. The effect of different light on the control of downy mildew was insignificant. The activities of POD, CAT, PAL, chitinase and β-1, 3-glucanase, and the contents of lignin treated with UV-C were significantly higher than those of the control. Blue light and blue light/UV-C had no significant effect on the activities of antagonistic enzymes. All treatments had no significant effect on the plant height, stem diameter, leaf area and yield of cucumber. The result of this study provides a theoretical basis for the control of cucumber disease in greenhouse. (authors)