Article | . 2016 Vol. 34, Issue. 6
Occurrence of White Rust and Growth of Chrysanthemum ‘Baekma’ by Control of Relative Humidity with Night Ventilation and Heating in the Greenhouse



Depratment of Horticultural Science, Mokpo National University1
Institute of Natural Resources, Mokpo National University2




2016.. 845:859


PDF XML




This study was conducted to examine the effect of nighttime ventilation and heating on changes in temperature and humidity, the occurrence of white rust, and growth of standard chrysanthemum (Dendranthema grandiflorum) ‘Baekma’ in a greenhouse. For the ventilation treatments, the mean nighttime humidity in the control greenhouse, which had a closed side window, was higher (94.5%), but the humidity in the natural and natural+fan ventilation treatments was lower (74.3% and 72.8%, respectively). The rate of occurrence of white rust at 34 days after treatment was 100, 98.3, 75.6, and 43.3% for the control, fan ventilation, natural ventilation, and natural+fan ventilation treatments, respectively. The number of infected leaves and telia were the lowest in the natural+fan ventilation treatment compared with the other treatments. The growth of the chrysanthemum 'Baekma' was significantly suppressed in the control because of the occurrence of white rust and high humidity, while plant height, number of leaves, stem diameter, and fresh weight were the greatest in the natural+fan ventilation treatment. For the heating treatments, the mean nighttime temperature of the control (RH 95% heating), which was heating and held at 95% humidity, was 18.4°C, while the temperature of the heating treatment, which was held at 70% relative humidity (RH 70% heating) was 25.8°C. The rate of occurrence of white rust (34.4%), number of infected leaves (0.9), and telia (1.0) were the lowest in the RH 70% heating treatment compared with the other heating conditions. Also, the RH 70% heating treatment showed the best growth in terms of plant height, stem diameter, number of leaves, and fresh weight. Therefore, the natural+fan ventilation and RH 70% heating treatments were effective for the control of white rust and the growth of standard chrysanthemum ‘Baekma’ in a greenhouse.



1.   

2.   

3.   

4.   

5.   

6.   

7.   

8.   

9.   

10.   

11.   

12.   

13.   

14.   

15.   

16.   

17.   

18.   

19.   

20.   

21.   

22.   

23.   

24.   

25.   

26.   

27.   

28.   

29.   

30.   

31.   

32.   

33.   

34.   

35.   

36.