Harvest Time and Cold Storage Duration of Lilium Oriental Hybrid Bulbs Affects Their Morphological Characteristics and Sugar Contents

Morphological characteristics and constituents in Lilium bulbs change depending on the harvest time and storage duration, and these changes affect bulb quality. This study was carried out to examine the impacts of different harvesting times and storage duration on the nose size and carbohydrate content of Lilium Oriental ‘Siberia’ and ‘Sorbonne’ bulbs.  For the harvest time study, bulbs were harvested weekly from September to November in a field farm in Taean, Korea. For the cold storage duration study, bulbs were harvested late November in the farm and stored at 0 °C. Bulbs were measured for morphological characteristics and total sugar and free sugar contents. As a result, bulb weight increased as time passed up to mid-October and then decreased due to a reduction of moisture content in bulbs. Regardless of cultivar, nose size increased with delaying the harvest time. Total sugar and sucrose contents increased as time passed to early November due to continuous translocation and accumulation of photosynthate. In the relation of cold storage duration with bulb characteristics, nose size increased with extending cold storage in both cultivars. During the storage period, monosaccharides (fructose and glucose) decreased until the end of March and then increased, whereas, sucrose showed a reverse trend. Total sugar was maintained at a certain level during the cold storage. Changes in carbohydrates content are considered to be related to the activity of enzymes involving carbohydrate metabolism and to affect nose growth in lily bulbs. This study was partially published in Flower Research Journal in 2012.