|Plants received the same irrigation volume over each two-week period from planting to flowering (~17 weeks).
MATERIALS AND METHODS
■ Bulbs of two suppliers of ‘Nellie White’ and sized 8/9 in circumference were planted in SunGro #4 using 15-cm diameter standard plastic pots on Dec. 2, 2009. Bulb weights were 148 g and 126 g for the two suppliers, respectively. A new cultivar (‘Grace’) was also included.
Plants were placed on open-mesh benches at a spacing of 30 / m2.
Irrigation frequency was based on three different ways: (i) once / two weeks; (ii) twice / week; and (iii) four times / week.
|Fig. 1 – The effect of irrigation frequency on Easter lilies ‘Nellie White’ and ‘Grace’ (source: Hastings Inc., Oregon). PHOTOS COURTESY DR. THEO BLOM, U OF GUELPH
On March 8, the irrigation volume was increased to 500 mL over a period of two weeks. The volumes of the individual waterings were adjusted accordingly. There were two blocks (=benches) with each block having three irrigation frequencies by two suppliers and with each experimental unit containing 18 plants.
Irrigation was overhead by pouring the irrigation solution directly onto the soil surface using a graduated cylinder. No plant growth retardants were applied. All plants were grown at a temperature of 16°C D/N with no DIF until the middle of February after which it was changed to 20/20°C.
At flowering, the following measurements were taken: date of flowering; plant height from top of pot to the base of the inflorescence as well as to the highest point of the inflorescence; and number of primary, secondary, tertiary and aborted buds, as well as the number of yellow leaves.
|Table 1. The effects of irrigation frequency on flowering date, plant height, number of healthy and aborted buds, as well as yellow and total number of leaves of Easter lily ‘Nellie White.’ Data represent the mean of 56 plants.