Effect of chlormequat (cycocel) on the growth of ornamental cabbage and kale (Brassica oleracea) cultivars 'Kamome White' and 'Nagoya Red'

Abstract

The effect of concentration and application method of chlormequat (cycocel), a plant growth retardant, on plant height and some other traits in Brassica oleracea cultivars 'Kamome White' and 'Nagoya Red' was assessed. Plant growth retardants are commonly applied to limit stem elongation and produce a more compact plant. The experiment was done as a factorial in randomized completely blocks design (RCBD) with four replications. Plants (40 days after transplanting) were sprayed and drenched with 500, 1000 and 1500 mg l(-1) cycocel. In each experiment, control untreated plants. Data were recorded the 60 and 90 days after transplanting. Based on analysis of variance (ANOVA), the effect of different treatments and their interaction on all traits was significant at 0.05 or 0.01 level of probability. Treatment of 1500 mg l(-1) cycocel resulted in about 50 and 20% shorter plants than control plants, 60 and 90 days after transplant. The growth of Brassica oleracea cultivar 'Kamome White' and 'Nagoya Red' decreased with increased cycocel concentration. Foliar sprays of cycocel controlled plant height of both cultivars. Results indicated that the shortest plants (9.94 and 11.59 cm) were those sprayed with 1500 mg l(-1) cycocel in cultivar 'Kamome White' after 60 and 90 days, respectively. The largest number of leaves (33.94) and highest leaf diameter (9.39 cm) occurred in cv. 'Nagoya Red', when drench was used. Maximum dry matter (14.31%) accumulated in cv. 'Nagoya Red', treated with spray.

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Journal of Environmental Biology, Vol. 36, 273-277, January 2015© Triveni Enterprises, Lucknow (India)
Introduction
Ornamental cabbage and kale (Brassica oleracea)
(Brassicaceae) is an important landscape plant for fall, winter and
spring gardens and parks. This attractive plant is resistant to cold.
Commercial value of ornamental cabbage and kale depends on
its height. Due to excessive stem elongation of ornamental
cabbage and kale in fall and early winter, there is a challenge for
maintaining a short, as shorter plants are more attractive and
easier to handle during marketing and planting. Plant growth
regulators are commonly applied to limit stem elongation and
produce a more compact plant. Production of high quality,
compact pot plants may be achieved through the use of plant
growth retardants, including cycocel (Messinger and Holcomb,
1986; Tayama et al., 1990). Effectiveness of plant growth
retardants depends on time and method of application,
concentration, type of species and cultivar, and type of target
organ as well physiological and environmental conditions
(Pobudkiewicz and Nowak, 1994; James et al., 1999). The most
common methods of application of growth retardants are foliar
sprays and media drenches (Al-Khassawneh et al., 1996). Plant
growth retardants can delay cell division and elongation of aerial
parts the plant as well restrict gibberellins biosynthesis, resulting
in reduced internodes and vegetative growth (Magnitskiy et al.,
2006). Cycocel is applied as foliar spray and drench. Adding
cycocel has also proved to be effective in controlling growth of
some other plants (Al-Khassawneh et al., 1996; Rossini Pinto et
al., 2005; Leclerc, 2006). Proper doses of cycocel foliar spray and
Effect of chlormequat (cycocel) on the growth of ornamental
cabbage and kale (Brassica oleracea) cultivars 'Kamome White' and
'Nagoya Red'
alicife@gmail.com
12 22
Abdollah Gholampour , Davood Hashemabadi *, Shahram Sedaghathoor and Behzad Kaviani
1Department of Horticultural Science, Rasht Branch, Islamic Azad University, Rasht, Iran
2Department of Horticultural Science, Rasht Branch, Islamic Azad University, Rasht, Iran
*Corresponding Author E-mail:
4147654919,
4147654919,
Abstract
Key words
The effect of concentration and application method of chlormequat (cycocel), a plant growth retardant, on
plant height and some other traits in Brassica oleracea cultivars 'Kamome White' and 'Nagoya Red' was
assessed. Plant growth retardants are commonly applied to limit stem elongation and produce a more
compact plant. The experiment was done as a factorial in randomized completely blocks design (RCBD)
with four replications. Plants (40 days after transplanting) were sprayed and drenched with 500, 1000 and
-1
1500 mg l cycocel. In each experiment, control untreated plants. Data were recorded the 60 and 90 days
after transplanting. Based on analysis of variance (ANOVA), the effect of different treatments and their
-1
interaction on all traits was significant at 0.05 or 0.01 level of probability. Treatment of 1500 mg l cycocel
resulted in about 50 and 20% shorter plants than control plants, 60 and 90 days after transplant. The growth
of Brassica oleracea cultivar 'Kamome White' and 'Nagoya Red' decreased with increased cycocel
concentration. Foliar sprays of cycocel controlled plant height of both cultivars. Results indicated that the
-1
shortest plants (9.94 and 11.59 cm) were those sprayed with 1500 mg l cycocel in cultivar 'Kamome White'
after 60 and 90 days, respectively. The largest number of leaves (33.94) and highest leaf diameter (9.39
cm) occurred in cv. 'Nagoya Red', when drench was used. Maximum dry matter (14.31%) accumulated in
cv. 'Nagoya Red', treated with spray.
Brassicaceae, Chlormequat, Drench, Ornamental cabbage and kale
Publication Info
Paper received:
22 June 2013
Revised received:
19 December 2013
Accepted:
31 March 2014
JEB Journal Home page : www.jeb.co.in
E-mail : editor@jeb.co.in
Journal of Environmental Biology
ISSN: 0254-8704 (Print)
ISSN: 2394-0379 (Online)
CODEN: JEBIDP

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Journal of Environmental Biology, January 2015
drench rate need to be assessed because they can either inhibit
or promote growth and development of cabbage and kale plant
growth depending on the amount used. Therefore, the aim of the
current study was to evaluate the effect of different methods and
concentrations of cycocel on some growth characters especially
plant height in Brassica oleracea cultivars 'Kamome White' and
'Nagoya Red'.
Materials and Methods
Plant materials and treatments : Seeds of ornamental cabbage
and kale (Brassica oleracea) cultivars 'Kamome White' and
'Nagoya Red' were obtained from Takii and Sakata Company
(Japan). Investigation was carried out on experimental field in
Rudesar city, located in the northern part of Iran with annual mean
rainfall of 958.6 mm; mean annual temperature of 17.3°C; mean
annual relative humidity of 78% and mean annual evaporation of
1044.2 mm, respectively.
Seeds were sown on August, 23 2010 in pots filled with
50% cocopeat, 30% perlite and 20% sand. Uniform size seedlings
(approximately 3-4 true leaves) were potted 40 days after seeding
in plastic pots filled with clay, manure, compost and sand
(1:1:1:1). Plants were treated with foliar and drench application @
-1
500, 1000 and 1500 mg l cycocel, 40 days after potting. Control
plants were sprayed and drenched with 6 ml per pot and 60 m l per
plant water.
Growth parameters : First data was calculated 60 days after
transplanting. Then plants were transferred to same pots and
same soil. Second data was calculated 90 days after
transplanting. Plant height was recorded 60 and 90 days after
potting. Leaf number, leaf diameter and dry matter percentage
were recorded 90 days after potting. Plant height and leaf
diameter were measured by a ruler. Leaf number was by obtained
counting from the center of each plot and
their mean was calculated. To obtain the plant dry matter, they
were cut from crown and dried at 105°C for 24 hr.
Statistical analysis : The experimental design was randomized
completely blocks design (RCBD) with factorial arrangement of
treatment consisting of four cycocel concentrations × two
treatment methods (spray and drench) × two cultivars ('Kamome
White' and 'Nagoya Red') × sixteen treatments totally × four
replications, 64 plots and 256 pots). Data were subjected to
analysis of variance (ANOVA) using MSTATC statistical software.
Mean comparison was carried out by employing Duncan's
Multiple Range test at α = 5%.
Results and Discussion
Based on the analysis of variance (Table 1), the effect of
different treatments and their interaction on plant height after 60
and 90 days of transplanting was significant at 0.01 level of
probability. There was no significant difference observed in the
effect of cultivar + kind of method on plant height after 60 days, but
was significant after 90 days. The interaction effect of cultivar +
method + concentration on plant height after 60 and 90 days was
significant at 0.01 and 0.05 level of probability, respectively. The
effect of cultivar on plant height was significant after 60 and 90
days (Table 1), and 'Kamome White' was better than 'Nagoya
Red'. Also, spray method had better effect on plant height after 60
and 90 days and caused shorter plant height than drench method.
Plant height decreased linearly with increasing cycocel
concentration (Table 2, Fig. 1 and 2). The effect of cycocel
concentration on plant height, at both stage of measurement (60
and 90 days), was significant. Plants of Brassica oleracea
cultivars 'Kamome White' and 'Nagoya Red' treated with cycocel
-1
were shorter than control plants (Fig. 1 and 2). 1500 mg l cycocel
treatment produced shortest plants (10.79 cm after 60 days and
the number of leaves
A. Gholampour et al.274
Table 1 : Analysis of variance (ANOVA) for the effect of different concentrations of cycocel, application method and type of variety on plant height,
number of leaves, leaf diameter and dry matter of ornamental cabbage and kale (Brassica oleracea)
Source of variations df Mean of squares
Plant height Plant height Number of leaves Leaf diameter Dry matter
after 60 days after 90 days after 90 days after 90 days
Replication (R) 3 0.018 0.103 0.346 0.092 0.043
** ** ns ** **
Cultivar (A) 1 5.581 10.360 0.00 2.610 59.946
** ** * ** ns
Method (B) 1 4.332 3.446 0.879 0.696 0.001
** ** ** ** ns
Concentration (C) 3 56.666 50.876 177.279 6.531 0.026
ns * ns ns ns
A × B 1 0.066 0.086 0.035 0.071 0.008
** ** * ** ns
A × C 3 0.901 0.232 0.560 0.629 0.054
** ** ns ns ns
B × C 3 1.398 0.602 0.496 0.150 0.175
** * * ns ns
A × B × C 3 0.158 0.052 0.569 0.134 0.057
Error 45 0.019 0.013 0.178 0.060 0.144
Total 63 - - - - -
CV (%) - 1.04 0.77 1.40 2.86 2.88
ns * **
: Non significant, : Significant at 5%, : Significant at 1%

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12.56 cm after 90 days) than control plants (15.20 cm after 60
days and 16.66 cm after 90 days). Among all treatments,
-
interaction effects of 'Kamome White' + spray method + 1500 mg l
1 of cycocel had least plant height (9.94 cm after 60 days and
11.59 after 90 days) (Table 2).
One of the most important application of plant growth
retardant is elevation of plant quality, especially ornamental
plants by reduction of vegetative growth. Plant growth retardants
decrease the internode length and eliminate the apical
dominance (Lee et al., 1999). Plant growth retardants increase
cytokinins which enhances the amount of leaf chlorophyll
(Rossini Pinto et al., 2005). Some of the most important factors
concerning plant growth retardants are type, time, number,
application method and concentration of growth retardant
(Cramer and Bridgen, 1998). Cycocel is an important plant growth
retardant. Several studies have revealed effectiveness of cycocel
in decreasing plant height (Rossini Pinto et al., 2005; Olivera and
Browing, 1993; Garner, 2004; Karlovic et al., 2004; Hashemabadi
and Zarchini, 2010). Studies of Al-Khassawneh et al. (2006) on
growth and flowering of Iris nigricans showed that cycocel
reduced plant height only at the highest drench concentration.
These researchers revealed that cycocel spray at higher
-1
concentrations (1000-1500 mg l ) reduced plant height. In the
current study, cycocel caused decrease in plant height in
ornamental cabbage and kale (Brassica oleracea) cultivars
'Kamome White' and 'Nagoya Red'. Karlovic et al. (2004) reported
decreasing height in Chrysanthemum by 2000, 3000 and 4000
-1
mg l cycocel. Hashemabadi and Zarchini (2010) showed that
-1
least stem length (29.93 cm) was obtained by using 1500 mg l
cycocel in rose. Saffari et al. (2004) sprayed Rosa damascena
-1
with cycocel and found that 3000 mg l cycocel decreased stem
275Effect of cycocel on growth of B. oleracea
Fig. 1 : The effect of different concentrations of cycocel on plant height of
Brassica oleracea cultivar 'Kamome White'. Left to right; 0, 500, 1000 and
-1
1500 mg l cycocel
Fig. 2 : The effect of different concentrations of cycocel on plant height of
Brassica oleracea cultivar 'Nagoya Red'. Left to right; 0, 500, 1000 and
-1
1500 mg l cycocel
10
9
8
7
6
5
4
3
2
1
0
Treatment
Fig. 3 : Effect of different treatments on leaf diameter of ornamental cabbage and kale (Brassica oleracea)
Leaf diameter (cm)
A1 A2 B1 B2 C1 C2 C3 C4 A1C1 A1C2 A1C3 A1C4 A2C1 A2C2 A2C3 A2C4
8.38b 8.78a 8.48b 8.69a
9.22a 8.91b 8.45c
7.75d
9.15a 8.68b
7.98c 7.72c
9.3a 9.14a 8.92ab
7.78c
Journal of Environmental Biology, January 2015

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Journal of Environmental Biology, January 2015
276
length by 5 cm as compared control. Increased application rates
did not positively influence plant development when compared to
-1
the lower rates used in the study. Cycocel (1000 and 2000 mg l )
decreased Zinnia plant height (Hojjati et al., 2009). The current
study confirms to these studies. Cycocel, also, reduced plant
height in Euphorbia and Bougeinvillia (Shekari et al., 2004), Rosa
(Saffari et al., 2004) and Pelargonium (Latimer et al., 1994). In
ornamental cabbage and kale and many ornamental plants,
spraying was the better than drenching, for decreasing plant
height (Garner, 2004). These results are consistent with our
findings. Other plant growth retardants such as prohexadione-
Ca, uniconazole, paclobutrazol, bayleton and daminozide are
applied for decreasing plants growth as spray or drench (Gibson
and Whipker, 2000; Bazzocchi and Giorgioni, 2003).
Based on the analysis of variance (Table 1), the effect of
application method of cycocel, variety, concentration, interaction
effect of variety and concentration and interaction effect of variety,
method and concentration on leaf number were significant at 0.05
level of probability. Also, the effect of different concentration of
cycocel on leaf number was significant at 0.01 level of probability.
Mean comparison obtained from the data showed that the largest
number of leaves per plant (33.94 and 33.88) was obtained from
'Nagoya Red' treated with drench without cycocel (control) and
variety of 'Nagoya Red' without cycocel, respectively (Table 2).
The production of leaf by drench method was higher than spray
method.
Based on analysis of variance (Table 1), the effect of
application method of cycocel, variety, concentration and
interaction effect of variety and concentration on leaf diameter
were significant at 0.01 level of probability. But, interaction effect
of variety and method, method and concentration as well as
variety, method and concentration on leaf diameter were not
significant on leaf diameter. Mean comparison obtained from the
data showed that maximum leaf diameter (9.39 cm) was obtained
from 'Nagoya Red' treated with drench and without cycocel
(control) (Table 2). Minimum leaf diameter (7.51 cm) was
-1
obtained from 'Kamome White' treated by spray with 1500 mg l
A. Gholampour et al.
Table 2 : Mean comparison of the effect of different concentrations of
cycocel, application method and type of variety on plant height, number
of leaves, leaf diameter and dry matter of ornamental cabbage and kale
(Brassica oleracea)
Traits
Treatments Plant height Plant height Number of
after 60 days after 90 days leaves after
(cm) (cm) 90 days
bba
Kamome White (A1) 12.96 14.61 30.22
aaa
Nagoya Red (A2) 13.55 15.41 30.22
bbb
Spray (B1) 12.99 14.78 30.10
aaa
Drench (B2) 13.52 15.24 30.34
aaa
Control (C1) 15.29 16.66 33.70
-1 b b b
500 mg L (C2) 13.88 15.89 32.08
-1 c c c
1000 mg L (C3) 13.08 14.92 28.84
-1 d d d
1500 mg L (C4) 10.79 12.56 26.25
cdb
A1B1 12.73 14.34 30.13
bca
A1B2 13.19 14.87 30.31
bbb
A2B1 13.26 15.21 30.08
aaa
A2B2 13.85 15.61 30.36
aba
A1C1 15.23 14.44 33.53
ccb
A1C2 13.61 15.40 31.97
ddc
A1C3 12.46 14.48 28.88
ffd
A1C4 10.57 12.09 26.50
aaa
A2C1 15.35 16.89 33.88
bbb
A2C2 14.15 16.37 32.19
ccc
A2C3 13.71 15.37 28.81
eed
A2C4 11.02 13.02 26.00
aaa
B1C1 15.29 16.65 33.78
ccb
B1C2 13.65 15.68 32.06
eec
B1C3 12.95 14.70 28.56
ggd
B1C4 10.11 12.07 26.00
aaa
B2C1 15.29 16.68 33.63
bbb
B2C2 14.10 16.09 32.09
ddc
B2C3 13.22 15.15 29.13
ffd
B2C4 11.47 13.04 26.50
aba
A1B1C1 15.27 16.41 33.75
cdc
A1B1C2 13.52 15.08 32.00
efd
A1B1C3 12.22 14.26 28.75
hie
A1B1C4 9.94 11.59 26.00
abab
A1B2C1 15.19 16.48 33.31
ccc
A1B2C2 13.69 15.73 31.94
ded
A1B2C3 12.70 14.70 29.00
ghe
A1B2C4 11.19 12.59 27.00
aaa
A2B1C1 15.31 16.89 33.81
cbc
A2B1C2 13.79 16.29 32.13
cdd
A2B1C3 13.68 15.13 28.38
hhe
A2B1C4 10.29 12.54 26.00
aaa
A2B2C1 15.39 16.88 33.94
bbbc
A2B2C2 14.50 16.45 32.25
ccd
A2B2C3 13.75 15.60 29.25
fge
A2B2C4 11.75 13.49 26.00
In each column means followed by the same letters are not significantly
different at 5 % level of probability using DMRT.
Fig. 4 : Effect of different treatments on dry matter of ornamental
cabbage and kale (Brassica oleracea)
Variety
Nagoya Red Kamome White
12.22b
14.16a
Dry matter (%)
14.5
14
13.5
13
12.5
12
11.5
11

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Journal of Environmental Biology, January 2015
cycocel (Fig. 3). Results showed that leaf diameter in 'Kamome
White' (8.38 cm) variety was less than that of 'Nagoya Red' (8.78
cm).
Studies of Al-Khassawneh et al. (2006) on growth and
flowering of Iris nigricans showed that maximum number of
leaves (average of 12.2-13.6) was obtained when plants were
-1
untreated with cycocel and paclobutrazol, sprayed with 250 mg l
-1
paclobutrazol, or drenched with 0.25 mg l . Our finding is
consistent with these results. Study of Agrawal and Dikshit (2008)
on Achras sapota demonstrated positive effect of cycocel on leaf
number. The current study showed that the highest dry matter
percentage was obtained from untreated plants with cycocel. In
agreement with our finding, Al-Khassawneh et al. (2006) also
showed that untreated plants had highest dry leaf weight. Study of
Garib Sahi (2009) on Zinnia elegans revealed that spraying plants
-1 -1
with 2000 mg l cycocel and 1 mg l CaCl increased dry weight of
2
leaves and roots.
Table 1 shows that only the effect of variety on dry matter
was significant at 0.01 level of probability and other treatments
had no significant effect on this trait. Table 2 shows that dry matter
percentage in 'Nagoya Red' (14.16%) was higher than that of
'Kamome White' (12.22%). Mean comparison obtained from the
data showed that highest dry matter percentage (14.31%) was
obtained from 'Nagoya Red' treated by spray without cycocel
(Table 2). Least dry matter percentage (11.99%) was calculated
from 'Kamome White' treated with drench without cycocel (Fig. 4).
-1
In conclusion, 1500 mg l of cycocel resulted in shorter
plants than control plants. The growth of Brassica oleracea
cultivar 'Kamome White' and 'Nagoya Red' decreased with
increase in cycocel concentration. Foliar sprays of cycocel
controlled plant height of both cultivars.
Acknowledgments
The authors would like to thank the Islamic Azad
University, Rasht Branch, especially Dr. Amirteimouri for their
financial support.
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277Effect of cycocel on growth of B. oleracea