EFFECT OF SOME PRE AND POST-HARVEST TREATMENTS ON THE KEEPING QUALITY OF POINSETTIA CUT-FLOWERS: II. VASE LIFE AS AFFECTED BY AGRICULTURAL PARACTICES AND HOLD SOLUTIONS.

A comprehensive postharvest study on poinsettia cut flowers was carried out during the two successive seasons of 1997/98 and 1998/99 at the Veget. and Flor. Dept., Faculty of Agriculture, Mansoura University to evaluate the effect of a Super Grow fertilizer at 0.0, 0.3, 0.6 and 0.9 g/plant once weekly combined with different irrigation levels of 150, 300, 450 and 600 ml/plant once every 3 days and different flower holding solutions as follows : sucrose (15 g/L), silver nitrate (25 ppm), boric acid (10 ppm), citric acid (10 ppm) and their interaction on vase life and quality of cut poinsettia flowers.
                The obtained results indicated that the heaviest flowers weight (19.87 %) resulted from treated plants with the fertilizer at 0.9 g/plant, irrigated with 450 ml/plant combined with holding flowers in citric acid (10 ppm) + sucrose (15 g/L) solution. Moreover, the highest water uptake (3.26 ml/fl), the best positive water balance (0.94 ml/fl./day) and the longest vase life (19.75 days) were produced from plants treated with the fertilizer at  0.9 g/plant, irrigated with 450 ml/plant and combined with holding flowers in silver nitrate (25 ppm). However, the fertilized plants with 0.3 g/plant and irrigated with the minimum water level of 150 ml/plant showed almost half the vase life prementioned (9.0 day) when hold in water only in the first season.
                The present study recommended that applying Super Grow fertilizer at 0.9 g/L once every week, with irrigation level at 450 ml/plant once per 3 days and combined with holding flowers in silver nitrate (25 ppm) to obtain the longest vase life and best quality of poinsettia cut flowers.