Pulsing on the postharvest physiology of two cultivars of Polianthes tuberosa L.

The effect of pulsing on the postharvest behavior of cut tuberose was evaluated in the cultivars ‘Mexican Single’ and ‘The Pearl’. Spikes of both were harvested with 1 or 2 of their basal buds open and treated with 20% sucrose and 200 mg of hydroxyquinoline citrate (sucrose + HQC). Pulsing increased the relative fresh weight of spikes, although water uptake in ‘The Pearl’ was greater regardless. After 5 days, visual quality was scored as ‘excellent’ and ‘good’ in ‘Mexican Single’ and ‘The Pearl’, respectively, and the greatest number of open and of senescent flowers occurred in the latter independent of pulsing. CIE L*C*h values and total sugars increased more noticeably among pulsed florets in ‘The Pearl’, whereas higher rates of respiration occurred in the unpulsed spikes of ‘Mexican Single’. Catalase activity was constant in ‘The Pearl’, although superoxide dismutase and peroxidase activities were higher and similar to, respectively, those of ‘Mexican Single’. These differences in physical, physiological and enzymatic behavior are important to consider when developing postharvest conservation and management strategies that are specific for each variety.