Growth, Coloration, and Subsequent Coloration after Removal of Film in Spring Red Leaf Lettuce Covered with Near Ultraviolet Ray-absorbing Film

• Published in: Horticultural Research (Japan) Vol. 16; no. 2; pp. 169 - 175
• Main Authors: Sato, Fumio, Yamauchi, Norihito
• Format: Journal Article
• Language: Japanese
• Published: THE JAPANESE SOCIETY FOR HORTICULTURAL SCIENCE 2017
• Subjects: anthocyanin; cultivar variations; plastic-tunnel culture; UV
• ISSN: 1347-2658; 1880-3571
• DOI: 10.2503/hrj.16.169

This study was carried out to investigate the effects of covering with near ultraviolet ray-absorbing (UVA) film on the growth and coloration of spring red leaf lettuce and to evaluate the subsequent coloration after removal of the film. The daily mean temperature and light quantity under the UVA film were similar to those under ultraviolet transmitting film. The growth of ‘Variety-nouaka’, ‘Black rose’, and ‘TLE-496’ was promoted by covering with UVA film, while that of ‘Red fire’, ‘Red falder’, and ‘Early span’ was not affected. Covering with UVA film decreased the leaf anthocyanin content by 30 to 40% in ‘Red fire’, ‘Red falder’, and ‘Early span’, and by 60 to 70% in ‘Variety-nouaka’, ‘Black rose’, and ‘TEL-496’. The leaf anthocyanin content at 3 days after the removal of the UVA film was higher than that just before removal in all varieties except ‘Red fire’. In ‘Variety-nouaka’ and ‘Black rose’, the increase in the leaf anthocyanin content occurred mostly until when the integrated light quantity of near ultraviolet rays reached around 600 W∙h∙m–2 after the removal of UVA film.