This document discusses the effects of chemical fertilizers and gibberellic acid (GA3) on the growth of citronella plants (Cymbopogon winterianus). It outlines an experiment to evaluate how different amounts of GA3, conventional fertilizer, and slow-release fertilizer impact the vegetative characteristics, chlorophyll content, carbohydrates, nitrogen, phosphorus, and potassium levels in citronella plants. The experiment involves applying various concentrations of GA3 and fertilizers to citronella plant slips and measuring their effects on the plant's physical and chemical properties over time.

1. Photo credits: http://davesgarden.com/guides/pf/showimage/175903/#b
http://towardsramrajya.blogspot.com/2010/10/harmful-effects-of-chemical-fertilizers.html
http://www.ehow.com/facts_5969723_different-fertilizers-plants.html
http://theimperfectgardener.com/fertilizing-your-seedlings/

2. Effects of Chemical Fertilizers and Gibberellic
Acid on the Physical and Chemical
Characteristics of Citronella Plant
(Cymbopogon winterianus)
Ma. Veah Luisa O. Pascasio

3. Outline

Introduction

Objectives

Cymbopogon winterianus

Materials and Methods

4. Introduction

Conventional Fertilizer

Common inorganic fertilizer (Chen, 2006)

Slow-Release Fertilizer

delays its availability for plant uptake and use
(Shaviv, 2005)

has semi-permeable coating (AAPFCO, 2007)

5. Introduction

Effects of chemical fertilizers on plants:

Protein and carbohydrate content increased in
Stevia rebaudiana induced with conventional
fertilizer (Patil, 2010).

Vegetative growth of Cryptostegia grandiflora
developed well in slow-release fertilizer
treatment (Hussein, 2009).

6. Introduction
 Gibberellic Acid (GA3)

Simple gibberellin (Tulis, 1964)

Isolated plant growth hormone (Cohen & Paleg,
1967; Tulis, 1964)

Promotes growth and elongation of cells but
different concentrations have relative effects to
various plant species (Sakr et al., 2003)

7. Objectives

To evaluate the effects of different amounts
of GA3, Conventional Fertilizer and Slow-
Release Fertilizer on growth and chemical
composition of Citronella Plant.

Vegetative Characteristics

Chlorophyll content, Carbohydrate
content, % of Nitrogen, Phosphorus,
Potassium

8. Objectives

To evaluate the effects of Conventional
Fertilizer and Slow-Release Fertilizer
combined with different amounts of GA3 on
growth and chemical composition of
Citronella Plant.

9. Significance of the Study

This study will provide basis for
developments of fertilization techniques and
parameters needed for maximum C.
winterianus growth.

10. Cymbopogon winterianus
(Citronella)

Taxonomic Classification
Kingdom Plantae
Phylum Magnoliophyta
Class Liliopsida
Order Poales
Family Pocaceae
Genus Cymbopogon
Species winterianus

11. Cymbopogon winterianus
(Citronella)
 Average leaf
length of 1 meter
 Glaborous leaf
and basal sheath
 Glaucous and
light green
surface
Photo credits: http://davesgarden.com/guides/pf/showimage/175903/#b Source: Jayashina, P. (1999). Citronella: A Literature Review

12. Cymbopogon winterianus
(Citronella)

Have the ability to produce essential oils
(Wijesekera, 1973)

Used as insect repellents and
aromatherapeutic agents (Leite et al., 1986;
Shah, et al., 2011; Wijesekera , 1973)

13. Materials and Methods

Sowing

One-year old clumps
will be split into slips.
Photo credits:http://www.tacethno.com/cymbopogon-citratum-lemongrass.html

Will consist of 45 plants:
 15 treatments= 5 fertilization treatments, 3 GA3
treatments

3 replicates

14. Materials and Methods
 Crop-Giant Fertilizer (8 N- 8 P2O5- 8 K2O)

3. 5 or 5 g / plant every week
 Osmocote Fertilizer ( 18 N- 6 P2O5- 12 K2O)

10 or 14 g / plant monthly

15. Materials and Methods

Gibberellic Acid

25 to 50 ppm twice a month
 Chemical fertilizers and GA3
concentrations will be estimated
according to the study of Hussein (2009)
and Maguire and Alley (2009).

16. Materials and Methods

Vegetative characteristics

Number of leaf blades

Size (mm2) of leaf blades

Fresh Weight of leaves

Dry Weight of leaves

17. Materials and Methods

Chlorophyll concentration

Arnon's equation (1949)
Chla (g l-1) = 0.0127 A663 – 0.00269 A645
Chlb (g l-1) = 0.0029 A663 – 0.00468 A645
Total Chl (g l-1) = 0.0202 A663 + 0.00802 A645

18. Materials and Methods

Carbohydrate concentration

Anthrone test

Amount of carbohydrate present in 100 mg
of the sample =
mg of glucose × 100
Volume of test sample

19. Materials and Methods

% Nitrogen

Kjeldahl Method

Ammonia by distillation followed by titration
of distillate with sulphuric acid

20. Materials and Methods

% Phosphosrus

Dry-ashing (Chapman & Pratt, 1961)
% P = ppm P (from calibration curve) × R × 100
Wt
1000

21. Materials and Methods

% Potassium

Flame photometry

Estimated using the calibration curve

22. Materials and Methods

Data Analysis

All analyses are to be run in triplicates.
All data will be subjected to Turkey's test
and ANOVA.

23. Literature Cited
Association of American Plant Food Control Officials (AAPFCO) (1995): Official Publication No. 48. Association of American Plant
Food Control Officials, Inc., West Lafayette, Indiana, USA.
Chapman, H.D. and P.F. Pratt. 1961. Methods of analysis for soils, plants and waters. Univ. of California, Division of Agricultural
Sciences, Berkeley.
Chen, J.H. (2006). The Combined Use of Chemical and Organic Fertilizers and/or Biofertilizer for Crop Growth and Soil Fertility.
Land Development Department, Bangkok 10900 Thailand
Cohen, D. & Paleg, L.G. (1967)Physiological Effects of Gibberellic Acid. X. The Release of Gibberellin-Like Substances by
Germinating Barley Embryos. American Society of Plant Biologists (1967). Retreived September 1967 from Plant Physiology
vol. 42 no. 9 1288-1296.
Hussein, M.M.M. (2009). Effect of Fertilizers and Gibberellic Acid on Growth and Chemical Composition of Cryptostegia
grandiflora. Journal of horticultural Science and Ornamental Plants 1 (2009): 27-38.
Jayashinha, P. (1999) Citronella: A Literature Review. Information Services Centre Industrial Technology Institute. (1999). from
Medicinal and Aromatic Plant Series No. 8 1391-5622.
Leite JR, Seabra Mde L, Maluf E, et al. (July 1986). "Pharmacology of lemongrass (Cymbopogon citratus Stapf). III. Assessment of
eventual toxic, hypnotic and anxiolytic effects on humans". J Ethnopharmacol 17 (1): 75–83.
Shah G, Shri R, Panchal V, Sharma N, Singh B and Mann A S. Scientific basis for the therapeutic use of Cymbopogon citratus, stapf
(Lemongrass). J Adv Pharm Technol Res. 2011 Jan-Mar; 2 (1): 3-8.
Shaviv, A. (2005). Controlled Release Fertilizers. International Fertilizer Industry Association (2005).
Wijesekera, R.O.B. (1973). The Chemical Composition and Analysis of Citronella Oil. Journal of the National Science of Sri Lanka, 1
(1973), 67-68