Effects of Different Concentrations of GA3 and BA Treatments, Storage Temperature and Duration on Rhizome and Subsequent Growth of Calla Lily Pot Plant (Zantedeschia aethiopica cv. childsiana)

Calla lily, an ornamental bulbous plant from Araceae family (consisting of seven species) is characterized by spadix inflorescence and utilized for cut flower as well as for pot plant. A greenhouse study was conducted in university college of Agriculture and Nature Resources of Tehran University, to evaluate the quantitative and qualitative characteristics of pot plant of Calla lily. The type of design was a completely randomized design of factorial arrangement and three replications. Experimental factors included preplant treatment with three levels of gibberellic acid (0, 100, 200 ppm) and three levels of benzyl adenine hormone (0, 100, 200 ppm) as well as two levels of storage temperature (10ºc, 20ºc) and two levels of rhizome storage duration (4 & 8 weeks). The results indicated that effect of duration of preplanting storage of rhizomes was significant on the number of days from planting to emergence. Also, storage temperature exerted a significant effect on this trait at 1% level. A temperature of 10ºC delayed the number of days from planting to emergence. According to significant four way interaction, maximum shoot number (7.67 shoots per rhizome) was obtained when 4 weeks of storage temperature of 20ºC × gibberellin solution at (200ppm) × benzyladenin solution at 200ppm were applied. However, a minimum of shoot number (1 shoot for every rhizome) was observed when 8 weeks of storage × temperature of 10ºC × dipping rhizomes in distillated water × foliar spraying with distillated water were employed. A comparison of means in evaluation of interaction effects of four factors indicate that plants which are related to treatment number 16, had the highest leaf area. This treatment was related to plants the rhizomes of which were dipped (during preplanting) in 200ppm gibberellin solution and were stored for four weeks in a temperature of 20ºC with their foliage being sprayed by distillated water. Meamwhile, application of gibberellin caused the increase in rhizome diameter (at the end of experiment) to be less than that in control treatment. So, maximum increase in rhizome diameter was observed in control treatment.