Potential of kaffir lime (Citrus hystrix) leaf extract as biopesticide in improving pre and post-harvest quality of chili (Capsicum annuum)

Abstract

Purpose: Chilli production in Malaysia is declining due to production problems such as pest and diseases which cause plants to become stunted, unhealthy, and damaged. To overcome this problem, most farmers prefer using chemical fertilizers and pesticides due to their fast reaction and effectiveness. In long term, application of these chemicals input may lead to an environmental damage and human health problems. To conserve our nature, the use of natural input in agriculture is highly recommended. Research Method: This study was conducted to identify the potential of plant extract, namely kaffir lime in increasing the plant productivity and reducing the severity of pests for chilli trees. The study was performed by spraying the chilli trees with 25, 50, and 75% (v/v) kaffir lime extracts. Controls consisted of plants without any treatment as negative control and plants applied with a commercial chemical pesticide as positive control. Findings: Results indicated that there were significant differences (p<0.05) between treatments with respect to all parameters including pre-harvest (plant height and pest severity) and postharvest (fresh weight and number of chilli pods) parameters except for the stem and crown diameter, soluble solid concentration, fruit firmness and colour measurement of chilli. The results found that chilli plants sprayed with 25% kaffir lime extract had the lowest pest infestation. Moreover, application of the 25% kaffir lime extract had produced the heaviest weight of chilli fruits and the highest number of chilli pods compared to other treatments including the positive control (chemical pesticide). Therefore, it was concluded that 25% kaffir lime extract produced healthier chilli plants, higher yield and better quality of chilli. Originality/ Value: Limited number of studies are available on eff ectiveness of kaffir lime-based insecticides. Therefore, this study was conducted as an effort towards understanding the versatility of kaffir lime leaves extraction as an alternative pesticide on chilli plants’ pre- and postharvest performance.

Full text

360
Potential of Kar Lime (Citrus hystrix) Leaf Extract as a Biopesticide in Improving
pre and post-harvest Quality of Chili (Capsicum annuum)
Noor Shahira Md Yuso1, Norhidayah Che Soh1*, Husni Hayati Mohd Rafdi1, Suhaizan Lob1,
Nurul Faziha Ibrahim1 and Nor Idzwana Mohd Idris1
Received:27th December 2021 / Accepted: 06th July 2022
ABSTRACT
Purpose: Chilli production in Malaysia is declining due to production problems such as pest and diseases
which cause plants to become stunted, unhealthy, and damaged. To overcome this problem, most farmers
prefer using chemical fertilizers and pesticides due to their fast reaction and eectiveness. In long term,
application of these chemicals input may lead to an environmental damage and human health problems. To
conserve our nature, the use of natural input in agriculture is highly recommended.
Research Method: This study was conducted to identify the potential of plant extract, namely kar lime in
increasing the plant productivity and reducing the severity of pests for chilli trees. The study was performed
by spraying the chilli trees with 25, 50, and 75% (v/v) kar lime extracts. Controls consisted of plants
without any treatment as negative control and plants applied with a commercial chemical pesticide as
positive control.
Findings: Results indicated that there were signicant dierences (p<0.05) between treatments with respect
to all parameters including pre-harvest (plant height and pest severity) and postharvest (fresh weight and
number of chilli pods) parameters except for the stem and crown diameter, soluble solid concentration, fruit
rmness and colour measurement of chilli. The results found that chilli plants sprayed with 25% kar lime
extract had the lowest pest infestation. Moreover, application of the 25% kar lime extract had produced
the heaviest weight of chilli fruits and the highest number of chilli pods compared to other treatments
including the positive control (chemical pesticide). Therefore, it was concluded that 25% kar lime extract
produced healthier chilli plants, higher yield and better quality of chilli.
Originality/ Value: Limited number of studies are available on eectiveness of kar lime-based insecticides.
Therefore, this study was conducted as an eort towards understanding the versatility of kar lime leaves
extraction as an alternative pesticide on chilli plants’ pre- and postharvest performance.
Keywords: Biopesticides, Chilli, Kar Lime, Pre-harvest, Post-harvest, Quality
1* Faculty of Fisheries and Food Science, Universiti Malaysia
Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia.
norhidayah.soh@umt.edu.my
https://orcid.org/0000-0002-1164-5125
The Journal of Agricultural Sciences - Sri Lanka
Vol. 17, No 3, September 2022. Pp 360-369
htt p://d o i . o r g /10 . 4038/ j a s .v17i 3 .9917
Open Access Article
INTRODUCTION
In Malaysia, chilli is one of the major crops
with a year-round high demand. Chilli is also
a cash crop and can be planted throughout the
year. It is intensively cultivated in three states
of Malaysia that include Kelantan, Johor and
Pahang with cultivation area of 536, 469 and
399 ha, respectively (DOA, 2019). Chilli is one
of the important ingredients used in many dishes
of Malaysians. It can be used either raw (green
or red), cooked or processed for the preparation
of other foodstus. Total chilli production in
Malaysia was 47, 015mt in 2015 but decreased
sharply to 43,738mt in 2016 (DOA, 2019). The
production was slightly increased to 26,354mt in
2019. However, this amount is still insucient
to meet the local demand mainly during festive

361
The Journal of Agricultural Sciences - Sri Lanka, 2022, Vol. 17 No 3
seasons. Malaysia has to import 39% of chillies
from Thailand and Vietnam to full this demand.
Pest and diseases are among the main causes in
the declining of chilli production. It is worsening
as the chilli plant itself is very susceptible to
pests and diseases (Touhidur et al., 2006). The
chilli plant can be infested by more than 21
insects and microbes (Dey et al., 2001). As
a result, the tree becomes stunted, damaged,
and nally dies. Currently, most farmers go
for chemical pesticide as a solution to pest and
disease problems. A large number of chemical
pesticides, insecticides, and fertilizers were used
to boost crop production. It resulted in successful
harvest and production during the early stages
of application, but during the last four decades,
the soil’s productivity has declined (Vanita et al.,
2014). Despite the growing popularity of organic
farming, conventional pesticides are still being
used in the agriculture practice and for sanitation
purposes; thus, pesticide residual occurrence
in environmental matrices is still a concern
(Srimurali et al., 2015). Although chemical
pesticides have a reputation as an eective and
rapid eect, regular and continuous use will
have a negative impact on human health and
the environment. The use of Excessive pesticide
resulted in destroying habitats. The health of
many birds, marine plants, and livestock is
threatened by toxic pesticides (Mahmood et al.,
2016). Overuse of toxins in marine environments
has been noted, posing a potential danger to sh
populations such as salmon. In addition, the
farmers and macro-invertebrates are also aected
by pesticides (Macneale et al., 2010).
One of the solutions to reduce the usage of chemical
pesticides is Integrated Pest Management
(IPM) principles, which prioritize physical and
biological regulation techniques (Munier and
Dongmo, 2010). It is a cross between traditional
farming, which uses a lot of inputs, and organic
farming, which does not use any industrial
pesticides or fertilizers. Another alternative is
sustainable agriculture where the cultivation of
fruit, bre, and other plants or animal products
cultivated in an environmentally sustainable
manner using various farming techniques. In this
concept, conservation of biodiversity in the soil
is important for agriculture’s long-term viability.
Recently, many studies related to plant extract
as biopesticides have been conducted. Plant
extracts are well known to contain a high toxicity
level towards a large array of insect pest (Saleem
et al., 2019). Plant extracts can inhibit insect
growth and development, result in signicant
weight loss in larvae, pupae, and adults. They also
prolonged the larval and pupal stages, as well as
the time it took for pupae to heal and adults to
emerge (Khanam et al., 1990). They might be
used as repellents, feeding deterrents, poisons,
or hormone mimics to prevent enemy attraction
(Odeyemi et al., 2008), oviposition, and growth
regulation (Rozman et al., 2007). Hence, it can be
concluded that botanical products are helpful and
desired tools in most pest control programmes
because they may be eective and frequently
complement the actions of natural enemies,
degrade quickly in the environment, have low
human toxicity, and reduce the possibility of pest
biotype selection (Greenberg et al., 2005).
Based on the above facts, the use of bio-pesticides
is very appropriate. However, there are some
challenges in applying this method in the crop
production process; i.e. lack of condence among
farmers on the eectiveness of biopesticides
because in general, the use of chemicals shows
a faster eect than natural methods. In addition,
the price of organic products in the market is also
expensive and burdensome for farmers. Through
studies like these, farmers have the potential to
use inexpensive materials to make their own
biopesticides for application on their respective
farms.
Despite many studies on plant extract, research on
kar lime leaf extract as biopesticide is scarce,
especially on chilli. Several studies reported
the kar lime extract with its ability as insect’s
repellent (Ikawati et al., 2017; Lim and Majid,
2019; Nawi et al., 2020). In 2010, Noveriza
conducted a study on the eect of bay leaf and
kar lime leaf extracts on Fusarium oxysporum.
They found that 5% of methanol extract of Kar
lime leaf signicantly inhibited the growth of F.
oxysporum with 95.6% of inhibition. Based on
previous studies, it can be summarised that kar
lime leaves have a high potential as biopesticides.
Since they are abundantly found in Malaysia,
therefore, this study was conducted to evaluate

362
Noor Shahira Md Yuso, Norhidayah Che Soh, Husni Hayati Mohd Rafdi, Suhaizan Lob,
Nurul Faziha Ibrahim and Nor Idzwana Mohd Idris
the eect of kar lime leaves extracts on pre and
postharvest performance of chilli plants.
MATERIALS AND METHODS
Study Plot and Planting Materials
This study was established at Rhu Tapai Centre
of Agriculture, Setiu, Terengganu, Malaysia
(5°30’48.6”N, 102°58’38.5”E). The planting
period was from June to October 2019. In this
study, the Capsicum annuum (chilli) Hybrid-461
was used and the seedlings were planted within 1
x 1 m planting distance in the experiment plots by
using an open fertigation system. All chilli plants
were applied with the same amount of fertilizer
and similar handling activities based on standard
agricultural practice to ensure that all plants were
growing healthily.
Preparation and Application of Kar Lime
Extract
The plant extract was obtained from kar
lime leaves. The leaves were picked randomly
from the tree and taken to the laboratory at the
University Malaysia Terengganu. All leaves
were washed under running tap water and left
under the shade to air dry for two days. Then,
a total of 200 g of dried fresh kar lime leaves
were mixed with 1L of deionized water and
homogenized in a Panasonic MXSM1031 mixer,
the mixture was ltered through muslin cloth and
the leaf extract was left in the refrigerator for 24
hours. It was diluted into 25%, 50% and 75%
(v/v) to a nal volume of 1L (Subramaniam et
al., 2005). The solution was used to spray all the
chilli plants from bottom to top with an average
dose of 50 ml for each plant. The solutions were
applied to the chilli plants every two weeks from
the rst two weeks after planting until chilli was
harvested. For chemical pesticides, the Zesban
EC Chlorpyrifos 21.2% brand used by farmers
in Malaysia was applied with 2.4 ml of chemical
pesticides, diluted in 1L with deionized water
and sprayed on the entire part of the chilli plant
at an average dose of 50 ml per plant.
Experimental Design
Prepared leaf extracts and commercial chemical
insecticides were applied according to the
experimental design (Table 01). Study plots were
allocated using a Randomized Complete Block
Design (RCBD) with a total of 10 replicates. The
randomization was performed using the table of
random numbers (Gomez and Gomez, 1984).
Data Collection
Preharvest parameters
Plant height: The height of the plants was
measured in centimetre (cm) from 1 cm above
soil line to shoot tip on the eld at two weeks’
interval by using a measuring tape.
Stem diameter: The diameter of the chilli
plants was measured every two weeks starting
from the second week after planting by using a
digital Vernier calliper and expressed in units of
millimetre (mm).
Table 01: Treatments used in the study
Treatment Description
P1 No pesticide applied
P2 Chemical pesticide
P3 25% kar lime extract
P4 50% kar lime extract
P5 75% kar lime extract

363
The Journal of Agricultural Sciences - Sri Lanka, 2022, Vol. 17 No 3
Crown diameter: The sum of two values taken in
two perpendicular axes from the plant’s top and
expressed in centimetres (cm).
Pest severity: The data were recorded every
two weeks from the second week after planting.
As noted in Table 02, the modication of pest
severity scoring was based on percentage of the
pest infestation (Ruchika and Kumar, 2012).
Postharvest Parameter
Fresh weight of chilli: The fresh weight was
recorded at harvesting stages and the former was
expressed in kilogram (kg).
Leaf area: The leaf area was measured by using
the leaf area meter (Model CI-202, CID Bio-‐
Science Inc., Camas, WA) after harvest and
expressed in unit of cm2.
Chilli Colorimetry: Colour indices were recorded
with a Minolta Chroma Meter (Model R200
Trimulus Colour Analyzer, Minolta Camera Co.
Ltd., Japan). The instrument was set to the white
standard for calibration. Colour was measured on
three sides of the chilli. The data were expressed
as L*, a*, and b* values. L* represents the
luminance factor going from 0 (black) to 100
(white). a* ranges from -60 to +60, indicating
the colour red (+60) and green (-60). During
this time, b* ranges from -60 to +60, indicating
yellow (+60) and blue (-60). a* and b * were
then used to calculate the hue angle (h° = tan1
b*/ a*) for colour interpretation. The hue angle
(h°) represents purple-red (0°), yellow (90°),
bluish-green (180°), and blue (270°). Chroma
(C*) is the intensity or saturation of a colour
where a low value indicates a dull colour while
a high value indicates a vivid colour, where it is
calculated from (a * 2 b * 2) (McGuire, 1992).
For each treatment, ten samples were measured
separately and the mean of ten measurements
was calculated.
Firmness and soluble solid concentration
(SSC): The chilli was cut into 2 x 2 cm pieces.
Chilli rmness was measured using TA-XT2
plus Texture Analyzer (Stable Micro System,
Godalming, UK) with a 2 mm stainless steel
probe (P2) and the data were recorded in a unit of
Newton (N). Meanwhile, SSC was measured
using digital refractometer and expressed in
°Brix.
Statistical Analysis
Data were analysed using One-way ANOVA.
The statistical analysis was performed using
IBM SPSS statistical software version 20.0, IBM
Corp, Armonk, USA.
RESULTS AND DISCUSSION
Preharvest parameter
Application of kar lime leaf extract on chilli
plants had a positive impact mainly on pest
severity and plant height attributes. Sprayed the
chilli plants with kar lime leaf extract ranged
of 25, 50 and 75% (v/v) that had successfully
reduced the pest severity on the plants (Table
03). In fact, kar lime extract had signicantly
(P<0.05) suppressed the pest severity when
Table 02: The pest severity score
Score
Percentage of leave
damage caused by
pest infestation (%)
Level
0 0 No pest infestation
1 1-25 Scattered appearance of few pests on the plant
2 26-50 Severe infestation of pests on any one branch of the plant.
3 51-75 Severe infestation of pests on more than one branch or half portion of the plant
4 76-100 Severe infestation of pest on the whole plant

364
Noor Shahira Md Yuso, Norhidayah Che Soh, Husni Hayati Mohd Rafdi, Suhaizan Lob,
Nurul Faziha Ibrahim and Nor Idzwana Mohd Idris
compared to chemical pesticides. According
to Loh et al. (2011), essential oil of kar lime
leaves was eectively killing the larvae of
tobacco army worm, Spodoptera litura, which
is one of the common pest in vegetables farm.
They found that the essential oil had antifeedant
properties due to β-citronellol (6.59%), linalool
(3.90%) and citronellol (1.76%) content which
resulted in severe growth inhibition of S. litura.
Although in this study, the kar lime leaf extract
compounds were not evaluated, the leaf extract
might have similar insecticidal properties of the
essential oil. On the other hand, the kar lime
leaf extracts’ eect was more superior than the
chemical pesticides which could be due to the
resistance developed in the insect pest towards
chemical pesticides in the planting area.
Lack of studies shows the potential of kar lime
extract on pest severity. However, kar lime
extract is known to have an antimicrobial eect
such as antibacterial and antifungal properties
(Lanciotti et al., 2004). The methanolic extract
from kar lime’ leaves can inhibit herpes
virus and can be used as mosquito repellent
(Chowdhury et al., 2009). In addition, several
studies reported that the kar lime extract shows
its ability as an insect repellent (Ikawati et al.,
2017; Lim and Majid, 2019; Nawi et al., 2020).
In a study conducted by Noveriza (2010), 5%
of methanol extract of bay leaf and kar lime
extracts can signicantly inhibit (95.6%) the F.
oxysporum. The results of this study showed
higher pest severity and infestation in the chilli
plants treated with chemical pesticides. It was
suggested that the insects’ pests surrounding the
planting area have built-up the resistance against
the chemical pesticides. Achio et al. (2012)
reported that frequent use of chemical fungicides
can increase the resistance of insect pests in
the planting area. Several studies reported the
kar lime extract with its ability as an insect
repellent. It also might be due to the extract’s
active ingredients to create a vapour barrier with
a repulsive avour or smell to insects, preventing
them from coming into touch with the treated
regions (Nerio et al., 2010). Plant extracts and
essential oils also have larvicidal and ovicidal
eects on insects, decrease oviposition, decrease
respiration, diminish adult emergence, and make
it dicult to identify host plants (Ali et al., 2017).
They also serve as antifeedants, repellents, and
attractants. It is also supported by previous study
that the leaf, peel, and fruit of the kar lime, in
particular, have therapeutic qualities (Srisukh et
al. 2012) and insect repellent action (Tawatsin et
al. 2001).
Height measurement is an important attribute
in measuring crop plant growth as it inuences
crop architecture, apical dominance, biomass,
resistance to lodging, tolerance to crowding and
mechanical harvesting (Liu et al., 2018). In this
study, application of 50% kar lime leaf extract
treatment had signicantly produced taller plants
if compared to chemical pesticides. It is notable
that application of kar lime leaf extract had
reduced the pest severity. Hence, plants sprayed
with the kar lime leaf extracts found to be
healthier that promoted a taller plant growth.
Table 03: Eect of dierent treatments on the preharvest parameter
Treatments Attributes
Pest severity Plant height (cm) Stem diameter (mm) Crown diameter (cm)
No Pesticide 2.02b 27.64ab 6.53 29.07
Chemical 2.38b 25.28b 6.56 27.39
25% kar lime extract 1.05a 28.44ab 7.84 28.36
50% kar lime extract 1.41a 29.31a 6.94 26.92
75% kar lime extract 1.38a 27.61ab 7.62 27.54
p- value 0.000** 0.040** ns ns
Mean values with the same letter in the same column for each attribute are not signicantly dierent at p<0.05, **: Signicant at
p<0.05, ns = not signicant.
Results presented in the table are average results from two weeks after planting until harvesting.

365
The Journal of Agricultural Sciences - Sri Lanka, 2022, Vol. 17 No 3
The previous study has shown a very strong
relationship between plant extract and plant
growth. In study conducted by Alam et al.
(2014), the application of seaweed extract
has increased the root yield of carrot due to
the increment of soil microbial. Plant extracts
have been used for decades as foliar- and soil-
applied treatments in crop production systems
due to the presence of a number of plant growth-
stimulating compounds (Wally et al., 2012).
Not only that, the plant extract is biodegradable,
non-toxic, non-polluting and non-hazardous to
humans, and animals. For that reason, it could
help to provide a favourable condition for more
abundant microbial community. Thus, the plants
are able to take up the nutrient more eciently
and promote better growth.
Postharvest Parameters
Dierent concentrations of kar lime leaf extract
sprayed on the chilli plants had signicant eects
on chilli fresh weight and number of chilli pods
(Table 04). The chilli collected from the plants
sprayed with 25% kar lime leaf extract was
1.17 kg heavier than the chilli obtained from
the control plants. However, treated the plants
with either chemical pesticides or dierent
concentrations of kar lime leaf extract had
produced similar chilli fresh weight which was
better than the control. This indicates that pest
control is critically required in chilli plants
regardless the type of the pest control used.
Results from this study is aligned with Awang et
al. (2015) showing that treated chilli plants with
pesticides had a better growth performance and
yield if compared to untreated plants.
Results present in Table 04 indicates that fresh
weight of chilli is directly related to the number
of chilli pods. Hence sprayed the plants with
25% of kar lime leaf extract had the highest
number of chilli pods, followed by 75% kar
lime leaf extract, chemical pesticides, 50%
kar lime leaf extract and control. However,
kar lime leaf extract had no signicant eect
on plant leaf area, chilli pod total soluble solid
content and the rmness. Finding from this study
agrees with the previous study which reported
that the application of plant extract such as
Moringa extract in the form of foliar spray has
signicantly increased the yield of onions, bell
pepper, soya beans, sorghum, coee, tea, chili,
melon, maize (Fuglie, 2000), and tomato (Culver
et al., 2012).
Colour is the primary consistency characteristic
that aects the market produce selection
(Malakar et al., 2018). During harvesting times,
lightness (L*), chroma (C*), and hue angle (h°)
of capsicum fruits were measured to monitor
surface colour changes. Colour is an important
factor in determining consistency and end-user
acceptance, including chillies. In red chillies,
the red lycopene pigment is degraded while
anthocyanin is synthesized concurrently during
ripening (Aza-González et al., 2017). According
to Naimah et al. (2016), higher value of a* while
lower value of b*, L*, h° and C* showed that
the chilli sample has more intense colour of red.
Statistical analysis for colour values of chilli
samples is shows in Table 05. In this study, various
biopesticides’ application did not signicantly
aect the colour indices of chilli below.
Table 04: Eect of dierent treatment on the postharvest parameter
Treatments
Fresh weight of
chilli per plant
(kg)
No. of chilli
pods per plant
Soluble solid
concentration
(°Brix)
Firmness of
fruit (N)
Leaf area
(cm2)
No Pesticide 3.39b 690b 7.53 6.31 750.07
Chemical 4.45ab 806ab 7.40 7.40 813.81
25% kar lime extract 5.10a 991a 7.53 9.61 892.50
50% kar lime extract 4.31ab 753ab 6.43 6.25 793.40
75% kar lime extract 4.42ab 837ab 7.47 6.30 760.09
p- value 0.024** 0.008** ns ns ns
Mean values with the same letter in the same column for each attribute are not signicantly dierent at p<0.05, **: Signicant at
p<0.05, ns = not signicant.

366
Noor Shahira Md Yuso, Norhidayah Che Soh, Husni Hayati Mohd Rafdi, Suhaizan Lob,
Nurul Faziha Ibrahim and Nor Idzwana Mohd Idris
CONCLUSIONS
Finding an alternative biopesticide towards
chemical pesticides is an eort in ensuring the
longevity of human and the earth, especially
on chilly plants that is well known for its
susceptibility for pest infestation and disease
infection. This study on the eect of kar lime
leaf extract on the chilli plants had produced
some positive results that were able to produce
healthier chilli plants with higher yield. This
study also revealed that 25% of kar lime leaf
extract had a potential as alternative biopesticides
for chilli plants as it produced the tallest plants
and the highest number of yield from a chilli pod.
This procedure is suggested to be used widely by
Malaysian farmers in order to mitigate frequent
application of chemical pesticides.
Table 05: Eect of kar lime extracts on lightness (L*), chromaticity value a*, b*, hue angle (h°),
and chroma (C*) of chilli
Treatments Attributes
L* a* b* h° C*
No Pesticide 38.19 36.98 22.06 30.83 43.07
Chemical 38.59 36.68 22.36 31.36 42.96
25% kar lime extract 37.97 34.34 23.81 34.65 41.81
50% kar lime extract 38.20 36.19 22.63 31.90 42.69
75% kar lime extract 37.52 36.62 23.00 32.04 43.27
Mean values with the same letter in the same column for each attribute are not signicantly dierent at p<0.05, *: Signicant at
p<0.05, ns = not signicant.
REFERENCES
Achio, S., Ameko, E., Kutsanedzie, F., and Alhassan, S. (2012). Insecticidal eects of various neem
preparations against some insects of agricultural and public health concern. International
Journal of Research in BioSciences, 1(2), p 11-19. Available at: http://www.ijrbs.in/index.php/
ijrbs/article/view/49 (Accessed: 22June2022).
Alam, M. Z., Braun, G., Norrie, J., & Mark Hodges, D. (2014). Ascophyllum extract application can
promote plant growth and root yield in carrot associated with increased root-zone soil microbial
activity. Canadian Journal of Plant Science, 94(2), 337-348. DOI: http://doi.org/10.4141/
cjps2013-135
Awang, N. A., Ismail, M. R., Omar, D. and Islam, R. (2015). Comparative study of the application
of jasmonic acid and pesticide in chilli: eects on physiological activities, yield and viruses
control. Bioscience Journal, 31(3), p 672-681. Retrieve from https://docs.bvsalud.org/
biblioref/2018/11/963866/comparative-study-of-the-application-of-jasmonic-acid-and-
pesti_626ovtV.pdf
Aza-González, C., Núñez-Palenius, H. G., and Ochoa-Alejo, N. (2017). Molecular biology of chili
pepper anthocyanin biosynthesis. Journal of the Mexican Chemical Society, 56, p 93–98. DOI:
https://doi.org/10.29356/jmcs.v56i1.281
Chaubey, A. N., Mishra, R. S. and Singh, V. (2017). Ecofriendly management of leaf curl disease of
chilli through botanical bio-pesticides. Plant Archives, 17(1), p 285-291. Retrieve from http://
plantarchives.org/PDF%2017-1/285-291(3483).pdf

367
The Journal of Agricultural Sciences - Sri Lanka, 2022, Vol. 17 No 3
Chowdhury, A., Alam, M. A., Rahman, M. S., Hossain, M. A. and Rashid, M. A. (2009). Antimicrobial,
antioxidant and cytotoxic activities of Citrus hystrix DC. fruits. Dhaka University Journal of
Pharmaceutical Sciences. 8(2), p 177-180. DOI: http://dx.doi.org/10.3329/dujps.v8i2.6035
Culver, M., Fanuel, T., & Chiteka, A. Z. (2012). Eect of moringa extract on growth and yield of
tomato. Greener Journal of Agricultural Sciences, 2(5), 207-211. Retrieve from https://
moringatrees.org/moringa-doc/moringa-increase-plant-growth.pdf
Department of Agriculture (DOA). (2019). Statistik Tanaman. Sub-sektor Tanaman Makanan. Unit
Geospatial Pertanian dan Statistik, DOA. p 62-67.
Dey P. K., Sarkar P. K., and Sam Choudhury A. K. (2001). Ecacy of dierent treatment schedules
of profenofos against major pests of chilli. Pestology 25(11): p 26–29
Fuglie LJ (2000). New Uses of Moringa Studied in Nicaragua: ECHO’s Technical Network Site-
networking global hunger solutions. ECHO, Nicaragua. Retrieved from https://www.
echocommunity.org/en/resources/15db05d7-4693-425b-9d86-468143bd0ec9
Gomez, K. A., and Gomez, A. A. (1984). Statistical procedures for agricultural research. John Wiley
& Sons.
Greenberg, S.M., Showler, A.T., and Liu, T.X. (2005). Eects of neem-based insecticides on beet
armyworm (Lepidoptera: Noctuidae). Insect Science 12, p 17-23. DOI: https://doi.org/10.1111/
j.1672-9609.2005.00003.x
Ikawati, S., Dhuha, M. S., and Himawan, T. (2017). Bioactivity of Citrus hystrix D.C. leaf extract
against cigarette beetle Lasioderma serricorne (F.). The Journal of Tropical Life Science, 7(3),
p 189-196. DOI: http://dx.doi.org/10.11594/jtls.07.03.01
Khanam, L. A. M., Talukder, D., and Khan, A.R. (1990). Insecticidal property of some indigenous plants
against Tribolium confusum Duval (Coleoptera: Tenebrionidae). Bangladesh Journal Zoology.
18(2): p 253-256. Retrieve from https://www.cabdirect.org/cabdirect/abstract/19921158103
Lanciotti, R., Gianotti, A., Patrignani, F., Belletti, N., Guerzoni, M. E. and Gardini, F. (2004). Use of
natural aroma compounds to improve shelf-life and safety of minimally processed fruits. Trends
in food science & technology. 15(3-4), 201-208. DOI: https://doi.org/10.1016/j.tifs.2003.10.004
Lim, L. and Majid, A. H. A. (2019). Plant derived pesticides (Citrus hystrix DC, Mentha x piperita
L., Ocimum basilicum L.) in controlling household ants (Tapinoma indicum F.), Pheidole
megacephala F., Monomorium pharaonis L.) (Hymenoptera: Formicidae). Pertanika Journal of
Tropical Agricultural Science, 42 (4). p 1321-1342. Retrieved from: http://www.pertanika.upm.
edu.my/resources/files/Pertanika%20PAPERS/JTAS%20Vol.%2042%20(4)%20Nov.%20
2019/11%20JTAS%201834-2019.pdf
Liu, F., Wang, P. , Zhang, X., Li, X., Ya n, X., Fu, D. and Wu, G. (2018). The genetic and molecular
basis of crop height based on a rice model. Planta, 247(1). P 1-26. DOI: http:// 10.1007/s00425-
017-2798-1
Loh, F. S., Awang, R. M., Omar, D and Rahmani, M. (2011). Insecticidal properties of Citrus hystrix
DC leaves essential oil against Spodoptera litura fabricius. Journal of Medicinal Plants
Research, 5(16). p 3739-3744. Retrieve from at http://www.academicjournals.org/JMPR

368
Noor Shahira Md Yuso, Norhidayah Che Soh, Husni Hayati Mohd Rafdi, Suhaizan Lob,
Nurul Faziha Ibrahim and Nor Idzwana Mohd Idris
Macneale, K. H., Kiney, P. M., and Scholz, N. L. (2010). Pesticides, aquatic food webs, and the
conservation of Pacic salmon. Frontiers in Ecology and the Environment 8: p 475–482. DOI:
https://doi.org/10.1890/090142
Mahmood I., Imadi S. R., Shazadi K., Gul A., and Hakeem K. R. (2016). Eects of Pesticides on
Environment. In: Hakeem K., Akhtar M., Abdullah S. (eds) Plant, Soil and Microbes. Springer,
Cham. 253-269. DOI: https://doi.org/10.1007/978-3-319-27455-3_13
Malakar, S., Sarkar, S., Kumar, N., and Jaganmohan, R. (2018). Studies of biochemical characteristics
and identication of active phyto-compounds of king chili (Capsicum chinense Jacq.) using
GC-MS. Journal of Pharmacognosy and Phytochemistry, 7(3), p 3100-3104. Retrieved from:
https://www.phytojournal.com/archives/2018/vol7issue3/PartAP/7-3-430-853.pdf
McGuire R. G. (1992). Reporting of objective color measurements. HortScience 27, p 1254-1255.
DOI: https://doi.org/10.21273/HORTSCI.27.12.1254
Munier-Jolain N. and Dongmo A. (2010). Evaluation of the technical feasibility of Integrated
Protection Systems in terms of operational functioning and work organization. How to adapt
solutions to local conditions? Agronomic Innovations 8: p 57–67
Naimah, R., Nur Amirah, Y., Adzemi, M. A., and Wan Zaliha, W. S. (2014). Quality and growth
development of Roselle grown on BRIS soil in relation to regulated decit irrigation. Journal
of Tropical Plant Physiology, 6, p 23-34. Retrieved from: https://mspp.org.my/les/jtpp/
jttpvol6/23-34-roselle.pdf
Nawi, M. A. M, Ishak, M. I., Rosli, M. U., Ayub, M. A. R. M., Khor, C. Y., Ahmad Termizi, S.
N. A. and Ishak, N. (2020). A novel green technology kar lime extract as lizard repellent.
IOP Conference Series: Materials Science and Engineering, p 743, 012010. DOI: https://doi.
org/10.1088/1757-899X/743/1/012010
Noveriza, R., and Miftakhurohmah, M. (2010). Efektivitas Ekstrak Metanol Daun Salam (Eugenia
polyantha) dan Daun Jeruk Purut (Citrus hystrix) sebagai Antijamur pada Pertumbuhan
Fusarium oxysporum. DOI: http://dx.doi.org/10.21082/jlittri.v16n1.2010.6-11
Odeyemi, O. O., Masika, P., and Afolayan, A. J. (2008). A review of the use of phytochemicals for
insect pest control. African Plant Protection. 14: p 1-7. Retrieved from: https://journals.co.za/
doi/pdf/10.10520/EJC87822
Rozman, V., Kalinovic, I., and Korunic, Z. (2007). Toxicity of naturally occurring compounds of
Lamiaceae and Lauraceae to three stored product insects. Journal of Stored Products Research.
43: p 349-355. DOI: http://dx.doi.org/10.1016/j.jspr.2006.09.001
Ruchika, K. and Kumar, D. (2012). Occurrence and infestation level of sucking pests: Aphids on
various host plants in agricultural elds of vadodara, Gujarat (India). International Journal of
Scientic and Research Publications, 2: p 1-6. Retrieved from: http://www.ijsrp.org/research_
paper_jul2012/ijsrp-july-2012-07.pdf
Saleem, M. S., Batool, T. S., Akbar, M. F., Raza, S., & Shahzad, S. (2019). Eciency of botanical
pesticides against some pests infesting hydroponic cucumber, cultivated under greenhouse
conditions. Egyptian Journal of Biological Pest Control, 29(1), 1-7. DOI: https://doi.
org/10.1186/s41938-019-0138-4

369
The Journal of Agricultural Sciences - Sri Lanka, 2022, Vol. 17 No 3
Srimurali S., Govindaraj S., Krishna Kumar S., and Babu Rajendran R. (2015). Distribution of
organochlorine pesticides in atmospheric air of Tamilnadu, southern India. International Journal
of Environmental Science and Technology, 12(6): p 1957–1964. DOI: https://doi.org/10.1007/
s13762-014-0558-3
Subramaniam, S. K., Siswomihardjo, W. and Sunarintyas, S. (2005). The eect of dierent
concentrations of neem (Azadiracta indica) leaves extract on the inhibition of Streptococcus
mutans (In vitro). Dental Journal, 38 (4): p 176-179. DOI: http://dx.doi.org/10.20473/j.djmkg.
v38.i4.p176-179
Touhidur, M. R., Idris, A. B., and Mohamad Ro, M. N. (2006). Population Abundance and Spatial
Distribution of Aphis gossypii Glover (Homoptera: Aphididae) and Coccinellids on Chilli
(Capsicum annuum L.). Journal of Tropical Agriculture and Food Science, 34(2): p 393-403.
Retrieved from: http://jtafs.mardi.gov.my/jtafs/34-2/Aphis%20gossypii%20Glover.pdf
Vanita, C., Piar, C., Avinash, N., Kaur J. K., and Yogesh P. (2014). Evaluation of heavy metals
contamination and its genotoxicity in agricultural soil of Amritsar, Punjab, India. International
Journal of Research in Chemistry and Environment, 4(4): p 20–28
Wally, O. S., Critchley, A. T., Hiltz, D., Craigie, J. S., Han, X., Zaharia, L. I., and Prithiviraj, B.
(2013). Regulation of phytohormone biosynthesis and accumulation in Arabidopsis following
treatment with commercial extract from the marine macroalga Ascophyllum nodosum. Journal
of plant growth regulation, 32(2), 324-339. DOI: http://dx.doi.org/10.1007/s00344-012-9301-9