Effects of Cultivars and Water Absorption Temperature on the Occurrence of Petal Curling in Cut Gerbera Flowers

When cut gerbera flowers absorb water after dry transport, some cultivars often exhibit petal curling, a phenomenon known as “Ben-sori” in Japanese. This study showed that the occurrence rate differed among gerbera cultivars, with ‘Aloha’, ‘Prime Time’ and ‘Kimsey’ being categorized as sensitive cultivars, while ‘Pinta’ and ‘Vivid’ were insensitive. In ‘Aloha’, petal curling caused the abaxial length and adaxial width of epidermal cells to be significantly shorter than in normal petals. ‘Aloha’ flowers harvested at later developmental stages were less affected by petal curling compared with those harvested at earlier stages. The petal length and width increased sharply at stage 4 (anthesis), and the development ray florets finished at stage 6 (flowers with anthers visible in three outermost rings in disk florets). Therefore, cut gerbera flowers that still have petal elongation potential may exhibit increased occurrence of petal curling symptoms. Lower absorption temperatures accelerated petal curling, and the most severe symptoms were observed at 5°C. Interestingly, when cut flowers absorbed water at 15°C, no symptoms were detected. We propose two ways to prevent the occurrence of petal curling in cut gerbera flowers: first, harvest flowers of sensitive cultivars at later developmental stages when anthers are visible in the two or three outermost rings of disk florets and second, allow water absorption at around 15°C after dry transport. These prevention strategies can resolve issues associated with petal curling for both flower retailers and customers and will improve the quality of cut gerberas.