Resource Information
     
Hot-Water Immersion of Chrysanthemum Cuttings, Hawaii, 1992  
     

By: A. H. Hara, T. Y. Hata, and B.K.S. Hu

Beaumont Agri. Res. Center, University of Hawaii-Manoa, 461 W. Lanikaula Street, Hilo, Hawaii 96720, Phone (808) 935-2885, Fax (808) 969-7923

HOST: Chrysanthemum: Chrysanthemum morifolium 'Iridon'

EXPERIMENTAL PROCEDURE
Phytotoxicity trials were conducted from 29 Oct through 4 Dec 1992. Chrysanthemum tip cuttings (2.5 inch) were immersed in 49oC water from 0 to 10-min at 1-min intervals. Each treatment time consisted of 24 cuttings except 0 and 5-min exposure times which consisted of 22 cuttings. Immediately following treatment, all cuttings including the control were cooled in a water bath at ambient temperature (26.1oC) for five minutes. Cuttings were subsequently basal treated with 0.1% indole-3-butyric acid rooting powder (IBA), planted in vermiculite in plastic trays, and kept under mist (13 s mist every 2.5 min) in a fiberglass greenhouse. Eleven days after treatment, data were taken on the percentage of cuttings with roots, mean length of the three longest roots, mean number of roots and mean dry weight of the root mass from 12 cuttings (4 reps of 3 cuttings per rep) selected at random from each time interval. The remaining cuttings were transplanted in 3 inch plastic pots containing a 3:1:1 mixture of peat, vermiculite and perlite; and placed randomly on a bench in a fiberglass greenhouse. Data on plant height, and percent survival were taken 36 days after treatment.

RESULTS
Cuttings survived hot-water immersion from 0 through 6-min; however, immersion > 7-min resulted in lower rooting percentage, survival of cuttings, and vegetative growth. There was no significant difference in root length among 1 and 2-min immersion and the control. There was no significant difference in the mean number of roots between 1-min immersion and the control.

Mean + SD growth of chrysanthemums

Exposure
time(min)		 Vegetativea
Growth(cm)		 Percent
Survival(n)		 Rootingb
Percentage		 Root
Number		 Rootc
Length(cm)		 Root Dryc
Weight (g)
0 15.5 + 1.3 100.0 (10) 100.0 40.6 + 4.7a 8.2 + 0.5a 0.2004 + 0.0097a
1 14.6 + 0.9 100.0 (12) 100.0 38.3 + 3.8a 8.0 + 0.7a 0.1392 + 0.0159b
2 15.7 + 1.6 100.0 (12) 100.0 26.9 + 4.6b 7.4 + 0.2ab 0.0932 + 0.0155c
3 12.5 + 1.2 100.0 (12) 100.0 22.8 + 4.8b 5.3 + 0.5bc 0.0376 + 0.0094d
4 10.5 + 1.4 100.0 (12) 100.0 7.8 + 1.9cd 2.7 + 0.8de 0.0092 + 0.0045e
5 10.8 + 1.4 100.0 (10) 100.0 7.9 + 0.6cd 2.2 + 1.0def 0.0069 + 0.0036e
6 11.6 + 2.0 100.0 (12) 100.0 17.6 + 2.7bc 3.5 + 1.3cd 0.0181 + 0.0054de
7 6.1 + 1.4 83.3 (12) 58.3 3.3 + 2.6d 0.5 + 0.2ef 0.0005 + 0.0006e
8 6.4 + 1.3 75.0 (12) 58.3 1.4 + 1.7d 0.4 + 0.2f 0.0008 + 0.0017e
9 5.9 + 1.2 41.7 (12) 41.7 4.5 + 2.8d 0.8 + 0.5ef 0.0018 + 0.0015e
10 7.5 + 1.4 91.7 (12) 66.7 3.2 + 2.0d 1.0 + 0.8ef 0.0027 + 0.0029e

a Data taken 36 days after treatment.
b Data taken 11 days after treatment (n=12).
c Data taken 11 days after treatment. Anova significant at P < 0.0001. Means followed by the same letter in a column are not significantly different by Scheffe's multiple comparison procedure.