PHYSIOLOGICAL POSTHARVEST BEHAVIOUR OF FLORAL ROSE STEMS (Rosa hybrida L.) IN RESPONSE TO PHOSPHORUS APPLIED IN PREHARVEST

During growth development of flowers, phosphorus nutrition is a factor that may influence the life of the flower in the vase. The objective of this study was to evaluate the effect of five levels of phosphorus (P) 0, 0.5, 1.0, 1.5 and 2.0 me.L-1 of P applied in pre-harvest, by using an open hydroponics system, on the physiological postharvest behavior of floral rose stems (Rosa hybrida L.) 'Classy' and 'Vega'. The variables assessed during the vase life of floral stems were: leaf and floral transpiration, leaf and petals swelling potential. In addition, the concentration of anthocyanins in petals at the time of harvest was evaluated. The pre-harvest application of P had a significant effect only on leaf transpiration; however, it was demonstrated that the longest vase life (15.8 days) of 'Classy' compared to 'Vega' (11.7 days) was directly associated with increased swelling potential in leaf and petals, higher floral transpiration and lower leaf transpiration rates in 'Classy'.