Effect of Mist Treatment on the Growth and Quality of Cut Rose 'Hanmaum' dining Summer

Abstract

During summer in Korea, the excessively high temperature causes growth retardation and quality reduction in cut roses grown in greenhouse. Mist treatments were conducted to reduce the temperature and avoid quality reduction of cut roses. The temperature change in the greenhouse, growth and quality of cut roses, and injuries caused by insects or fungi were investigated during mist treatment. Daily maximum temperature reduced as the number of mist treatment increased, resulting in 6 degrees C reduction by mist treatment for 10 seconds at 5 min interval. This temperature reduction occurred only when maximum temperature was over 40 degrees C in greenhouse, and not when it was less than 40 degrees C or rainy and/or cloudy day. Plant height and fresh weight of the cut roses were increased at the range of 10-20% by mist treatment. As frequency of mist treatment increased, however, malformed flowers increased and vase life of cut rose was largely shortened. The injuries by insects like as beet armyworm larvae and scale insect increased as well. In conclusion, it is recommended that mist treatment must be used when the daily maximum temperature in a green house is over 40 degrees C and forecasting for disease or insects should be conducted as well.