Petunia axillaris is a very important economically cherished plant because of its ability to produce beautiful fragrant flowers that come in different colours, which invariably gives an aesthetic value. However, it is important to deepen the understanding for possible culture improvement. This study examined the effect of three watering frequencies on the growth and survival of Petunia from juveniles. The treatments consist of low water application (once in a week), normal application (twice per week) and high-water application (thrice per week). The following data were collected from the seedlings; plant height, number of flowers, number of dead plants. Also, destructive sampling was carried out to assess length and width of leaf, root depth, as well as number of leaves and number of dead leaves. Statistical analysis was performed with R-studio software. Growth and survival rate performances were significantly (p < 0.05) affected by watering frequencies. The multivariate analyses of principal component (PCA), showed that, all growth parameters except the number of dead leaves were correlated positively to each other. The results indicated that high flexibility of the species to be cultured with minimum requirements of water supply equating to reduction in production costs.

1. Effect of Watering Frequencies on the Growth and Survival of Petunia Axillaris in a Controlled Environment
Effect of Watering Frequencies on the Growth and Survival
of Petunia Axillaris in a Controlled Environment
*1Chinedu Felix Amuji, 2Salvador Hernández Navarro
1Department of Crop Science, Faculty of Agriculture, University of Nigeria, 410001 Nsukka, Enugu State, Nigeria
2Department of Agricultural and Forestry Engineering, Higher Technical School of Agricultural Engineering, La Yutera
Campus, Madrid Avenue 44, 34071 Palencia, Spain
Petunia axillaris is a very important economically cherished plant because of its ability to produce
beautiful fragrant flowers that come in different colours, which invariably gives an aesthetic value.
However, it is important to deepen the understanding for possible culture improvement. This
study examined the effect of three watering frequencies on the growth and survival of Petunia
from juveniles. The treatments consist of low water application (once in a week), normal
application (twice per week) and high-water application (thrice per week). The following data were
collected from the seedlings; plant height, number of flowers, number of dead plants. Also,
destructive sampling was carried out to assess length and width of leaf, root depth, as well as
number of leaves and number of dead leaves. Statistical analysis was performed with R-studio
software. Growth and survival rate performances were significantly (p < 0.05) affected by watering
frequencies. The multivariate analyses of principal component (PCA), showed that, all growth
parameters except the number of dead leaves were correlated positively to each other. The results
indicated that high flexibility of the species to be cultured with minimum requirements of water
supply equating to reduction in production costs.
Key words: culture, management, ornamentals, plant performance.
INTRODUCTION
Petunia axillaris is an annual plant in the family
Solanaceae. The plants are grown solely for their aesthetic
value. In other words, they are ornamental plants grown
for decorative purposes in gardens and landscape design
projects, as household plants, for cut flowers and
specimen display (Cantor et al., 2015). The aesthetic
features displayed by the plant includes; the stem, bark
and most importantly the flowers which occur in different
colours depending on the species gene. It has been
reported that Petunias can tolerate relatively harsh
conditions and hot climates (Brown and Moncada, 2018).
Water is one of the most important factors that affects the
biological make up of plant growth and health; it is
essential for many plant processes like photosynthesis,
nutrient transport, and cell expansion and development
(McElrone et al., 2013). Irrigated agriculture is the leading
use of water by humanity (Shortle and Griffin, 2001).
Generally, plants response to water stress in different
ways ranging from adaptive changes and/or deleterious
effects (Chaves et al., 2002). For ornamental plants, they
may become smaller and look less appealing resulting in
lower revenue or a longer growing period even in a nursery
setting (Jones and Tardieu, 1998). The irrigation of farms
has made it possible for crops to be grown in the deserts,
greenhouses and other normal natural unsuitable
conditions.
Physiological responses of plants are frequently used as
accurate indicators of plant water stress (Bhattacharjee
and Saha, 2014), which usually involve tissue size
measurements as an indicator. These are done using
appropriate equipment and the variability due to growth
compared. Assessment of petunia plant growth to
determine the actual quantity of water required to save and
minimise labour cost, was done in this work. This attempt
*Corresponding Author: Chinedu Felix Amuji,
Department of Crop Science, Faculty of Agriculture,
University of Nigeria, 410001 Nsukka, Enugu State,
Nigeria. Email: felix.amuji@unn.edu.ng; Tel: +234 803
757 9415; Co-Author 2
Email: inpaisal@iaf.uva.es; Tel:
+34 979 108350; Fax: +34 979 108440
Research Article
Vol. 5(2), pp. 086-091, November, 2019. © www.premierpublishers.org, ISSN: 3369-9526
International Journal of Horticultural Science and Ornamental Plants

2. Effect of Watering Frequencies on the Growth and Survival of Petunia Axillaris in a Controlled Environment
Amuji and Navarro 087
to study the effects of different watering frequencies on this
valuable plant’s (Petunia axillaris) seedling growth in the
nursery will provide the much-desired practical information
for accurate culture practice. This information will
invariably assist the farmers and growers to be able to
maximize the benefits inherent in the processes involved
given a similar condition. Therefore, this research was
formulated with the specific objective of determining the
best watering frequency (irrigation) for petunia plant
seedling raised in the nursery at juvenile stage from
sowing date to first six weeks of growth.
MATERIALS AND METHODS
Location
The plants were grown at the greenhouse (Plant
Environment Laboratory) of Higher Technical School of
Agricultural Engineering, University of Valladolid, Palencia
campus, Spain (420251N, 40301W). The greenhouse was
maintained at constant temperature and humidity
throughout the period of the experiment. Potted media
containers with great surface for optimal stability during
cultivation and transportation were used. The media was
‘Sustrato 28®’; a plant season substrate produced by
Pindstrup-Mosebrug SAE. E-09140 Sotopalacios, Burgos,
Spain. It was supplied in bags of 100 litres with the
following composition: 70% peat 5-20 mm, 30% black peat
0-10 mm, approximately pH 6.0 (aqueous solution),
wetting agent, an aqueous detergent which facilitates the
absorption of water, microelements and a compound of
nitrogen, phosphorus and potassium enough for the first
20-30 days. The container was ‘Maceta Termoformada
Desch 10.5cm L Baja®’ produced by Projar Grupo
Inspiring Green Technology, Spain
Experimental treatments and irrigated crop studies
The treatments consist of low water application (200ml of
water once in a week-1x), normal application (200ml of
water twice in a week-2x) and high-water application
(200ml of water three times in a week-3x). Twenty
containers filled with the media were potted having seven
days from sowing Petunia axillaris seedlings for each of
the treatments (total number of 60 plants i.e. 20 x 3). An
overtop sprinkler irrigation system was used for the
experiment. The potted plants were separated from each
other for all the treatments. The setups were observed for
five weeks’ period of the experimentation at a uniform
climatic condition in the greenhouse.
Measurements and Data collection
The following parameters were measured from all the
seedlings in the nursery and compared among the
treatments: plant height (at the third and fifth weeks),
number of flowers (at the third and fifth weeks), percentage
mortality for the plants (at the fifth week).
Destructive sampling after the fifth week of treatments
application were carried out for assessment of the
following: length of leaf (cm), width of leaf (cm), root depth
(cm) and shoot height (cm), as well as number of leaves
and number of dead leaves.
Statistical Analyses
Collected data were expressed as mean. Analysis of
variance (ANOVA) was used to determine differences
among the watering frequencies, using R-Studio version
3.6.1 scientific graphing data analysis software (R, 2019).
The differences were considered to be significant at 0.05
(P < 0.05). Tukey multiple comparison test was used to
determine the level of significant among the treatment
means. The multivariate analyses of principal component
(PCA) was also performed among all the variables
measured.
RESULTS AND DISCUSSION
There was a significant (p < 0.05) effect due to the watering
frequencies on the number of dead leaves produced by the
plants. Petunia plants with the lowest watering application
treatments (1x) had the highest number of dead leaves.
This showed that lesser the frequency of water application
on Petunia plants in nursery the more the leaves die off.
Significant (p < 0.05) differences were observed among
the treatments on number of leaves produced by the
Petunia plants. Plants with thrice per week water
applications (3x) had the highest number of leaves. The
twice per week (2x) and once a week (1x) treated plants
had similar number of leaves (Figure 1).
Figure 1: The effects of the different watering frequencies
on some measured parameters of the petunia plants.
The observations on the width and length of the Petunia
plant leaf measured suggest that; 3x treated plants had the

3. Effect of Watering Frequencies on the Growth and Survival of Petunia Axillaris in a Controlled Environment
Int. J. Hort. Sci. Ornam. Plants 088
highest values. However, from the analysis of variance
(ANOVA) result and means comparison using Tukey test,
it was observed that there was no significant difference in
leaf length and width between the 3x and 2x treated plants.
Results of this experiment indicated substantial sensitivity
of Petunia plants leaf to water stress and this was similar
to the observations of Pallardy and Rhoads (1999) on
Populus clones, Shawquat et al. (2014) on soybeans; and
also, on Petunia plants by Klock-Moore and Broschat
(2001) under subirrigation systems.
No significant effect was detected among the three
watering frequencies on the root depth. This suggested
that the plants roots developments were not altered by the
treatments. However, the water frequencies application
affected the shoot height of the Petunia plants significantly
(p < 0.05) as seen in Figure 1. The 1x treated plants had
the tallest shoots. Boutraa et al. (2010) had reported that
water application can influence the plant shoot height on
some cultivated wheat plants. The development of plant
root and shoot system is strongly influenced by growing
conditions such as water stress (Franco, 2011). However,
just as observed in this experiment, root growth can be
less affected when compared to shoot growth. A similar
result was observed on Lonicera implexa (Navarro et al.,
2008), Lotus creticus (Franco et al., 2001), Nerium
oleander L. (oleander) (Banon et al., 2006), and Silene
vulgaris (Arreola et al., 2006).
The Petunia plants are basically grown for its wide range
of flower colours, sizes and the plant architecture in
general. A mature organ of petunia flower is organized in
four concentric whorls. There are five sepals, five petals,
five stamens; and a blobbed carpel in the inner whorl (Krol
and Chua, 1993). The line graph for the number of flowers
as affected by the different water applications on the
Petunia plants are given in Figure 2. Comparable
differences were observed among the treatments at the
fifth week of application. The Petunia plants with 1x
treatments had higher number of flowers than others. This
effect was in a negative form because, lesser the water
application level the higher number of flowers. This
observation was in accordance with the submission of
Katsoulis et al. (2006) that irrigation (watering) frequency
negatively affects rose flower production. However,
Petunia plants under 3x treatments started growing
significantly (p < 0.05) taller than others from the third
week and this trend continued to the fifth week (Figure 3).
Our work also agreed with similar finding of Scheiber and
Beeson (2006), who observed quality negative response
due to reduced irrigation volumes of Petunia ×hybrida
‘Rose Madness’ on flowers and shoot mass.
Figure 2: Average plant height for different watering
frequencies treated plants at 3rd and 5th week of the
experiment
Figure 3: Average number of flowers observed in the
different watering frequencies treated petunia plants at the
3rd and 5th week of the experiment.
Highest mortality rates were observed on the petunia
plants treated with 1x. This was followed by those that
received 2x. However, very few dead plants were
observed on the 3x treated plants (Figure 4). The
multivariate analysis of Principal components (PCA) of the
parameters measured in the experiment (Figure 5 and
Table 1) showed that length of leaf had positive direct
effect on the number of leaves, shoot height and width of
leaf. This implies that the longer the leaf the more widely
developed it is, and also the taller the plant shoots system
becomes. Furthermore, this indicates that those petunia
plants with larger leaves are the tall ones. The explanation
will be that the production of larger leaves (per leaf area of
the plant) supports the petunia plant shoot growth. The
large leaf area so produced will directly correlate with more
photosynthesis and the plant will consequently grow taller
(Reich, 2004). In accordance, King (1998) reported that as
the larger leaves give advantage to an increased light
interception capacity of the plant for photosynthesis; there
is a resultant increase in the overall height of the plant
shoot.

4. Effect of Watering Frequencies on the Growth and Survival of Petunia Axillaris in a Controlled Environment
Amuji and Navarro 089
Table 1: Principal component analysis values of parameters measured
number of leaves number of dead leaves length of leaf width of leaf shoot height root height
number of leaves 1 -0.3753 0.32923 0.3288 0.09194 0.18347
number of dead
leaves
-0.3753 1 -0.04643 0.09919 0.24665 -0.3483
length of leaf 0.32923 -0.04643 1 0.82595 0.66171 -0.0225
width of leaf 0.3288 0.09919 0.82595 1 0.74306 0.07188
shoot height 0.09194 0.24665 0.66171 0.74306 1 0.11743
root depth 0.18347 -0.34836 -0.02254 0.07188 0.11743 1
Figure 4: Percentage mortality of the petunia Figure 5: Principal component analysis chart of parameters
plants at different watering frequencies. measured.
Figure 6: Petunia axillaris plants as used in the experiment.
CONCLUSION
Changes in climate and demand for water resources are
likely to cause an increased pressure to reduce water use,
especially for domestic home garden nursery growers.
Rather than give up on the process because of the
enormous challenge imposed by water scarcity in
developing countries like Nigeria, the data presented by
this investigation indicates that acceptable results can be
achieved in a plant like Petunia. Its production in the
nursery with once a week water application of 200 ml can
give plants with tall shoots and high number of flowers.
Because of the overriding importance of water to plant
growth, managing water application (irrigation) is the most
critical cultural operation in farm nurseries.
number of leaves
number of dead leaves
length of leaf
width of leaf
shoot height
root height
-1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0
-1.0
-0.8
-0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
PrincipalComponent2
Principal Component 1
Petunia axillaris plants during their
vegetative growth stage
A flower of the Petunia axillaris plant
Petunia axillaris plants during their
vegetative growth stage
A flower of the Petunia axillaris plant

5. Effect of Watering Frequencies on the Growth and Survival of Petunia Axillaris in a Controlled Environment
Int. J. Hort. Sci. Ornam. Plants 090
Further research is required to investigate this irrigation
frequency effect on petunia plants in the nursery for a
longer period of time and possible with genetically different
species. More research is also needed in the traditional
nursery setting. This right water application frequency
when discovered and adopted will save time, labour and
money for maximum benefit in petunia plant production.
And also ensures continuous production as a feature of
urban landscape and aesthetic, despite restrictions and
challenges of water supplies in most developing countries
of the world.
ACKNOWLEDGEMENTS
This study was supported by Erasmus Mundus Dream
Project scholarship at University of Valladolid, Palencia
Campus, Spain as part of master’s degree project work in
Advanced technologies for agroforestry development.
REFERENCES
Arreola, J., Franco, J. A., Vicente, M. J., Martinez-
Sanchez, J. J. 2006. Effect of nursery irrigation regimes
on vegetative growth and root development of Silene
vulgaris after transplantation into semi-arid conditions.
The Journal of Horticultural Science and Biotechnology,
81(4), 583-592.
Bañon, S., Ochoa, J., Franco, J. A., Alarcón, J. J.,
Sánchez-Blanco, M. J. 2006. Hardening of oleander
seedlings by deficit irrigation and low air humidity.
Environmental and Experimental Botany, 56(1), 36-43.
Bhattacharjee, S., Saha, A. K. 2014. Plant water-stress
response mechanisms. In Approaches to Plant Stress
and their Management (pp. 149-172). Springer, New
Delhi, India
Boutraa, T., Akhkha, A., Al-Shoaibi, A. A., Alhejeli, A. M.
2010. Effect of water stress on growth and water use
efficiency (WUE) of some wheat cultivars (Triticum
durum) grown in Saudi Arabia. Journal of Taibah
University for Science, 3(1), 39-48.
Brown D., Moncada K. 2018. “Growing Petunias”
University of Minnesota Extension Office Report.
University of Minnesota, United States of America.
(Available online at https://extension.umn.edu/flowers/
growing-petunias retrieved 15/10/19)
Cantor, M., Krizbai, E., Erzsebet, B. U. T. A. 2015. The
Behavior of Some Petunias Varieties for Improvement
the Romanian Assortment. Bulletin of University of
Agricultural Sciences and Veterinary Medicine Cluj-
Napoca. Horticulture, 72(1), 39-44.
Chaves, M. M., Pereira, J. S., Maroco, J., Rodrigues, M.
L., Ricardo, C. P. P., Osório, M. L., Pinheiro, C. 2002.
How plants cope with water stress in the field?
Photosynthesis and growth. Annals of botany, 89(7),
907-916.
Franco, J.A. 2011. Root development under drought
stress. Technology of Knowledge Transfer e-Bulletin; 2
(6): 1-3. Universidad Politecnica de Cartagena, Spain.
Franco, J. A., BaňÒ, S., Ferna Ndez, S., Leskovar, D. I.
2001. Effect of nursery regimes and establishment
irrigation on root development of Lotus creticus
seedlings following transplanting. The Journal of
Horticultural Science and Biotechnology, 76(2), 174-
179.
Jones, H. G., Tardieu, F. 1998. Modelling water relations
of horticultural crops: a review. Scientia Horticulturae,
74(1-2), 21-46.
Katsoulas, N., Kittas, C., Dimokas, G., Lykas, C. 2006.
Effect of irrigation frequency on rose flower production
and quality. Biosystems engineering, 93(2), 237-244.
Klock-Moore, K. A., Broschat, T. K. 2001. Irrigation
systems and fertilizer affect petunia growth.
HortTechnology, 11(3), 416-418.
King, D. A. 1998. Influence of leaf size on tree architecture:
first branch height and crown dimensions in tropical rain
forest trees. Trees, 12(7), 438-445.
Krol, A. R., Chua, N. H. 1993. Flower Development in
Petunia. The Plant Cell, 5(10), 1195.
McElrone, A. J., Choat, B., Gambetta, G. A., Brodersen, C.
R. 2013. Water uptake and transport in vascular plants.
Nature Education Knowledge, 4(6):2-12
Navarro, A.V. M. J. Martínez, Sánchez, J. J., Franco, J. A.,
Fernández, J. A., Bañón, S. 2008. Influence of deficit
irrigation and paclobutrazol on plant growth and water
status in Lonicera implexa seedlings. ISHS Acta
Horticulturae, 782: 299-304.
Pallardy, S. G., Rhoads, J. L. 1997. Drought effects on leaf
abscission and leaf production in Populus clones. In
12th Central Hardwood Forest Conference ed. By
Jeffrey, W., Loftis D.L., Barnes, T. and Muller, R.A.
(1999) Gen. Tech. Rep. SO-24, Asheville, NC: US
Department of Agriculture, Forest Service, Southern
Research station; 330p.
R. 2019. R Development Core Team: A Language and
Environment for Statistical Computing (Version 3.6.1).
Vienna, Austria.
Reich, A., Holbrook, N. M., Ewel, J. J. 2004.
Developmental and physiological correlates of leaf size
in Hyeronima alchorneoides (Euphorbiaceae).
American Journal of Botany, 91(4), 582-589.
Scheiber, S. M., Beeson, R. C. 2006. Petunia growth and
maintenance in the landscape as influenced by
alternative irrigation strategies. HortScience, 41(1),
235-238.
Shawquat, A. K., Mamun, A. A., Mahmud, A. A., Bazzaz,
M., Hossain, A., Alam, S., Karim, A. 2014. Effects of salt
and water stress on leaf production, Sodium and
Potassium Ion accumulation in soybean. Journal of
Plant Sciences; 2(5): 209-214.
Shortle, J. S., Griffin, R. C. 2001. Irrigated agriculture and
the environment. Edward Elgar Publishing Ltd.
Cheltenham, United Kingdom. ISBN: 1840645032

6. Effect of Watering Frequencies on the Growth and Survival of Petunia Axillaris in a Controlled Environment
Amuji and Navarro 091
Accepted 18 November 2019
Citation: Amuji CF, Navarro SH (2019). Effect of Watering
Frequencies on the Growth and Survival of Petunia
Axillaris in a Controlled Environment. International Journal
of Horticultural Science and Ornamental Plants 5(2): 086-
091.
Copyright: © 2019. Amuji and Navarro. This is an open-
access article distributed under the terms of the Creative
Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium,
provided the original author and source are cited.