Effects of relative humidity, calcium supply, and forcing season on tulip calcium status during hydroponic forcing
2003
Nelson, P.V. | Kowalczyk, W. | Niedziela, C.E. Jr | Mingis, N.C. | Swallow, W.H.
The tulip (Tulipa gesneriana L.) cultivars ‘Abra’, ‘Christmas Marvel’, ‘Golden Melody’, and ‘Jingle Bell’ were forced hydroponically during two early forcing periods (FPs) and ‘Golden Melody’ and ‘Oscar’ during two late FP. Treatments were factorial combinations of two relative humidity (RH) levels (42 and 82%) and five Ca(NO3)2 levels (0, 2.5, 5, 10, and 20 mM). The study was conducted in growth chambers at a constant 19 °C and a 14 h daylength in which 70 μmol s−1 m−2 PPF was provided by cool white florescent lamps. Calcium uptake and accumulation were less at 82% RH as compared to 42% RH; however, the incidence of Ca deficiency symptoms did not increase at the higher RH. A 2.5 mM Ca(NO3)2 solution prevented Ca deficiency symptoms in all cultivars except ‘Abra’ during all FP. Plants in FP4 (26 March–18April) weighed less and accumulated less Ca than the same cultivars in the earlier FP. Calcium uptake and transpiration were lower in distilled water and 20 mM Ca(NO3)2 than other Ca(NO3)2 treatments after day 22 in FP1 (22 December–26 January). Total Ca content was lower in the flowers of ‘Golden Melody’ tulips forced in distilled water than the Ca(NO3)2 treatments. Calcium dry weight (DW) concentration and total Ca content in the flowers of ‘Golden Melody’ tulips forced at 42% RH were higher than at 82% RH. Total Ca content in the flowers of ‘Golden Melody’ tulips decreased from FP3 to FP4.
显示更多 [+] 显示较少 [-]