Analysis of the pre- and post-sale quality of Poinsettia pulcherrima.

摘要

Poinsettia cultivars Gold Finger, Monet, Petoy Red, Success, Cortez, Freedom Bianca, Freedom Rosa, Freedom Rossa, Sonora Jungle and Sonora Marble were grown in 14-cm pots at 8 plants/m2 with one pinching in greenhouses with a night minimum temperature of 16℃ and 70% RH. Plant quality was assessed at week 48 as this marked the beginning of the sales period. Post-sale quality was assessed from week 50 to week 8 of the following year. During this period plants were kept in minimum night temperaturesof 18℃ and maximum temperatures of 22℃ , 50-60% RH and 200-1000 lux for 9-10 h/day. Leaf and bract drop were monitored every 4 days. All the cultivars yielded good quality plants with Gold Finger being the most vigorous and the Sonora cultivars the least vigorous. The Freedom cultivars exhibited exceptional ornamental value because of their good bract/leaf colour contrast, compact habit and low susceptibility to leaf yellowing. However, they do suffer from low inflorescence number and poor canopy symmetry. The cultivars with light green leaves were more susceptible to leaf yellowing and bract drop. Only the plants with dark green leaves but especially the Sonora cultivars, Freedom Rosa and Freedom Bianca exhibited lasting ornamental value.