THE EFFICACY OF LED LIGHTS AND GROWTH REGULATOR SPRAYS AT CONTROLLING CHILLING INJURY IN LEUCOSPERMUM POTTED PLANTS
Leucospermum cut flower stems are prone to chilling injury and leaf yellowing as a result of long-term cold storage below 4°C as is required when exporting Leucospermum by sea freight from South Africa to European markets. Potted plants of Leucospermum Memory (L. cordifolium selection) and Leucospermum Rigoletto (L. cordifolium × L. glabrum) were subjected to LED lighting (treatments included full, half and no light levels) and growth regulator treatments (500 mg L-1 Promalin® and MaxCelTM respectively) to evaluate their efficacy for alleviating cold-induced injuries after a three week cold storage period. The plants subjected to a full light LED treatment showed a significant reduction in chilling injury and leaf yellowing in comparison to plants subjected to the no light treatment. Promalin® and MaxCelTM showed no or little ability to reduce the associated postharvest cold storage disorders. It was concluded that LED at a light energy level of 25.03 ± 2.09 μmol m-1 s-1 was effective at reducing leaf yellowing and chilling injury. A range of Leucospermum cultivars should also be evaluated for its suitability to be placed in cold-storage with supplemented LED lighting.
Hoffman, E.W., Miller, M. and Louw, E.-L. (2015). THE EFFICACY OF LED LIGHTS AND GROWTH REGULATOR SPRAYS AT CONTROLLING CHILLING INJURY IN LEUCOSPERMUM POTTED PLANTS. Acta Hortic. 1097, 47-54
Proteaceae, leaf yellowing, long-term cold storage, pin-cushions, sea freight