Freesia cut flowers: pulse uptake and the effects of sucrose, 8-hydroxyquinoline sulphate and silver thiosulphate pulses : a dissertation submitted in partial fulfilment of the requirements for the degree of Bachelor of Horticultural Science (Honours) in the University of Canterbury [Lincoln College]

Abstract

Freesia x hybrid flowers were harvested from seed-grown plants over 4-5 months and used in a five experiment sequence. Three experiments investigated the effects of temperature, relative humidity (RH), dehydration and solution on the 12 hour pulse uptakes in darkness. The other experiments investigated 18-19 hour separate pulses, first at 7.5 ± 1.5°C (83 ± 4% RH) and later at 20.5 ± 1.0°C (60 ± 5% RH), of 8-hydroxyquinoline sulphate (8-HQS, “Chinosol W”, 0 – 800 mg 1⁻¹), sucrose (0 – 320 g 1⁻¹), and silver thiosulphate (STS, 0 – 1.6 mM AgNO₃ at 1:8 ratio). The vase life, floret opening and floret size of the pulsed inflorescenses were assessed at 20.5 ± 1.0 °C, 55 ± 5% RH and 12 hour diurnal 15.5 ± 0.3 µ mol m⁻² s ⁻¹ PPFD lighting with the stems in distilled water. Multiple stem replicates were used. Early season inflorescences had the longest vase life and seemed less sensitive to pulse treatment. Pulse condition did not greatly affect freesia quality. 40°C solutions did shorten vase life by 0.75 day. Dry storage did not affect postharvest.