저온환경이 수박의 냉해발생과 형태적 증상에 미치는 영향 = Incidence and Visual Symptoms of Chilling Injury in Greenhouse Watermelons

다국어 초록 (Multilingual Abstract)

This experiment was carried out to investigate temperature distribution in the double layer plasticgreenhouse and chilling injury to watermelons grown during a cold season. Temperatures on easternand western sides were about 6.2% and 14.7%, respectively, lower than that of central section in asouth-north oriented greenhouse. Daily mean temperature in the northern part was about 1-2oChigher than that in the southern part of the greenhouse. In terms of vertical temperature distributioninside the greenhouse, temperature at ground surface was approximately 1oC lower during the dayand 0.5oC higher during the night than that in the upper part, 2 m from the ground surface. Leafmould medium kept higher ground temperatures as compared to sandy soil, red clay soil, or clay soil.More chilling injured plants were observed in the western side as compared to the eastern side, and inthe northern and southern sides as compared to the central part of the greenhouse. A symptom ofchilling injury on leaves was upward curling, followed by chlorosis and necrosis. A severe symptom ofchilling injury to plants was the breakdown of vascular bundles. Root growth was more susceptiblethan stem or leaf growth to low temperatures. At 30oC, main and lateral roots grew vigorously, whilelateral root growth was inhibited at 22oC and root growth was stopped at 14oC and 6oC. Small andpuffy fruits with dark green surface were produced at low temperatures. In cold season cultivation ofwatermelons, it is suggested that plants be transplanted in the central part and train to sides of thegreenhouse in order to reduce chilling injuries.