MINSTRY OF EDUCATION
MINITRY OF AGRICULTURE AND
VIETNAM ACADEMY OF AGRICULTURE SCIENCES
TRAN THI MINH LOAN
BIOLOGICAL AND ECOLOGICAL CHARACTERISTICS
OF Meloidogyne sp. PARASITISED ON EGGPLANT AND
CONTROL METHODS BY INTEGRATED NEMATODES
MANAGEMENT IN LAM DONG
Specialization: Crop Protection
SUMMARY OF PH.D AGRICULTURAL THESIS
HA NOI, 2019
The work was completed at: Vietnam Academy of Agricultural Sciences
Supervisor: 1. Asscociate Professor Pham Thi Vuong
2. Asscociate Professor Nguyen Van Ket
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Eggplant is a fruit vegetable and is high nutrient and economical value, developed and expanded
in Vietnam as well as Lam Dong province. Although, eggplant is planted and took care easily but,
disadvantages of eggplant production are detected by many diseases such as green wilt, leaf spot,
Verticillium wilt and plant-parasitic nematodes.
Root-knot nematodes (Meloidogyne spp.) are common pathogens parasitised on most plants
worldwide. Among the nematodes discovered in Vietnam, root-knot nematodes is the most
serious parasitism and thriving pest in recent years. In Lam Dong, root-knot nematodes is one of
the major pest parasitised on solanaceae, in generally and on eggplant, as a result, decreasing of
quality and yield, increasing other diseases. There have been several researches about root-knot
nematodes parasitised on eggplant, however, very little has been conducted about distribution, as
well as biological and ecological characteristics of root-knot nematodes on Solanaceae and
eggplant in Lam Dong to control them. For these reasons, we carried out the topic "Research on
biological and ecological characteristics of Meloidogyne sp. parasitised on eggplant and methods
control by integrated nematodes management in Lam Dong" to (i) determine root-knot parasitised
nematodes species composition on eggplant, (ii) study biological and ecological characteristics,
and (iii) provide effective solutions for control root-knot nematodes toward integrated nematodes
management in eggplant production in Lam Dong as well as in Vietnam.
2. Research aims and objectives
Objectives: the objectives of the research are: (i) to identify species composition root-knot
nematodes parasitised on eggplant, (ii) to determine biological and ecological characteristics of M.
incognita, and (iii) to provide proposing methods to prevent them toward integrated nematodes
management, contributing production of eggplant and solanaceace safety, effectively and
Theoretical significance: The thesis has supplemented new scientific data of species
composition of root-knot nematodes, biological and ecological characteristics, rules of
reproduction, development and parasiticide of M. incognita. On that basis, effective methods and
solutions to control root-knot nematodes, protecting the environment and contributing to safe
production of eggplants safety in Lam Dong was proposed. The thesis is a reference for
agricultural students, researcher, teacher and sciences.
Practical significance: Proposing methods to control root-knot nematodes effectively and
safely, contributing to improved process of the eggplant production toward integrated nematodes
management for the purpose of stable, effective and sustainable production in Lam Dong as well
as in Vietnam, particularly, chemical pesticides are abused to control nematodes today. This
thesis is also a document to help managers and farmers identifying symptoms of M. incognita on
eggplant and decide effectively management solutions of root-knot nematodes.
4. Subjects and scope of the research
4.1. Research subjects
The subject of study is root-knot nematodes (Meloidogyne sp.) parasitised on eggplant.
4.2. Research scope
Thesis content: Identifying species composition of parasitic root-knot nematodes on
eggplant; Studying biological characteristics of M. incognita detected on eggplant; Accessing
some of ecological conditions (soil type, organic fertilizers, rainfall, soil moisture, temperature
and different eggplant varieties) affected parasitic characteristics and population of M. incognita
detected on eggplant; Providing solutions to control M. incognita detected on eggplant according
to integrated management (cultivation methods, biological methods, physical methods, chemical
Location: Identifying species composition, affecting ecological conditions on root-knot
nematodes and open field experiments were conducted in three vegetable growing areas in Don
Duong, Duc Trong and Da Lat in Lam Dong province. Greenhouse experiments were conducted
in the Department of Agriculture and Forestry, Dalat University. In vitro experiments including
idetification of root-knot nematodes, extractation vermiform root-knot nematodes from soil and
root, lilfe cycle of M. incognita were carried out in Plant Protection Laboratory, the Department
of Agriculture and Forestry, Dalat University and laboratories of Nematology Department,
Institute for Agricultural and Fisheries Research (ILVO), Flanders, Belgium.
5. Novel contributions of the thesis
This thesis makes contributions:
(i) To provide some new data of species composition of root-knot nematodes
(Meloidogyne spp.), biological and ecological characteristics of M. incognita detected on
eggplant in Lam Dong province.
(ii) To propose methods to control root-knot nematodes detected on eggplant in Lam Dong
according to integrated nematodes management to decrease damage; to reduce using chemical
pesticides; to complete the protocol of eggplant production following safety and organic
cultivation in Lam Dong as well as in Vietnam.
CHAPTER 1. LITERATURE REVIEW
Eggplant (Solanum melongena) is a fruit vegetable with high economic value. In over the
world, there were about 1.6 million hectares growing eggplant. In Vietnam, eggplant is grown in
recent years and becomes popularly in many areas throughout the country. In Lam Dong,
eggplant was planted reaching about 1,944 ha, with an average yield of 47.6 tons/ha in 2017.
Growing eggplant can bring high income but unstable, because eggplant is a susceptible
crop to many diseases, insects and nematodes, in which, Meloidogyne spp. are an important group
of plant parasites reduced eggplant yield and quality. Root-knot nematodes are the most important
and common pest worldwide, causing economic damages of agricultural crops in tropical and
subtropical areas. Root-knot nematodes were reduced eggplant yield up to 95% (Di Vito, 1986).
There are many species of root-knot nematodes detected on eggplant, in which two species M.
incognita, M. javanica detected in South Asia, Nepal and India, three species M. incognita, M.
arenaria and M. javanica detected in Egypt.
Until now, very few surveys have been conducted and evaluated the role of root-knot
nematodes on crops in Vietnam, mainly focused on some industrial perennial plants. Some survey
reported the species composition of root-knot nematodes on vegetables in South of Vietnam and
Lam Dong provine in the 1990s. However, there is no report studying root-knot nematodes on
On over the world, there have been a number of studies involves the different ecological
conditions such as temperature, humidity, climatic factors affecting life cycle of M. incognita on
eggplant as well as control methods. However, in Vietnam, there are no research results of
biological and ecological characteristics as well as control methods root-knot nematodes on
1.2 Research situation
18.104.22.168 Research history, distribution and damage thresholds of root knot nematodes in agriculture
Root-knot nematodes are obligate parasites which can be found in varieties of plants play
an important role in agriculture. They caused serious economic losses in agriculture. The earliest
report of observation of plant parasitic nematodes was in the mid-18th century (1743) when
Needham observed pests on wheat by microscope. However, until the middle of the 19th century,
root-knot nematodes had been identified morphological characterictics clearly.
Typical symptoms of root-knot nematodes are many galls on the root system. M. incognita,
M. javanica and M. arenaria are the major of root-knot nematodes, in which, M. incognita is the
most important plant parasitic nematodes. Like other plant pathogens, root-knot nematodes cause
estimated crop yield decline. According to Taylor and Sasser (1978), for infected areas, without
control methods, crop yield may be drop to 24.5% - 85.0%.
22.214.171.124 Classification and identificationy root knot nematodes
Root-knot nematodes (Meloidogyne) belongs to kingdom Animalia, phylum Nematoda
Potts, 1932; class Chromadorea Inglis, 1983; order Rhabditida Chitwood 933; suborder
Tylenchida Thorne, 1949; family Meloidogynidae Skarbilovich, 1959; genus Meloidogyne Goldi,
1987. Initially, technique identification of root-knot nematodes is mainly based on morphological
characteristics, describes perineal pattern characteristics of females and the length of secondstage juveniles. However, at the end of the 20th century, root-knot nematodes is identified by
isozyme analysis and molecular identification methods.
126.96.36.199 Biological and ecological characteristics of root-knot nematodes
There are many stages growth and development of root-knot nematodes changing in
different shapes which could be called sexual dimorphism. Females are the pear-shaped, less
moving into the root. The first-stage juveniles (J1) are within the eggs. The second-stage juveniles
are worm shape, move in the soil. After infecting roots, the second-stage juveniles (J2) develop
into the third juveniles (J3) and the four juveniles (J4), then swollen to adult females or form
males moving in the soil. Usually, root-knot nematodes development depends on species, host
and temperature. In general, life cycle is 15 days to 70 days.
Root-knot nematode are detected on different varieties of crop with the different ways. The
density of root-knot nematodes in soil depends on soil type and ecological climate conditions.
Species composition and nematode density in soil are related to 65% of rainfall and 58% of soil
temperature. Soil texture and structure also affects nematodes density. Sandy are more favorable
than clay. The density of nematodes in soil is related to organic materials added to soil. In general,
growth, density and survival of root-knot nematodes depend on the host, ecological conditions
such as temperature, soil moisture, organic content and soil texture.
188.8.131.52 Methods control root-knot nematodes
Using control methods aims to limit harmful effects of nematodes on crop, stabilize yield
and quality, bring high economic efficiency. There are 6 control methods of root-knot nematodes
to protect crops including: crop rotation, sanitation, resistant varieties, biological methods,
physical methods and nematicide. Integrated nematode management is studied and implemented
to efficiently control nematodes and reduce using nematicide.
1.2.2 Viet Nam
184.108.40.206 Research history, classification, distribution, biological and ecological characteristics of root
Root-knot nematodes have been called many Vietnamese names. In Vietnam, the first
nematode study was published by Hungarian scientist named Andrassy in 1970 with more than
30 species of plant parasitic nematodes and free living nematodes. According to Nguyen Ngoc
Chau and Nguyen Vu Thanh (2000), plant parasitic nematodes were divided into 30 varieties, 11
families, 4 order. In particularly, root knot nematodes parasitised in Vietnam including 10 species
of M. arenaria, M. cynariensis, M. graminicola, M. incognita, M. javanica, M. exigua, M.
cofeicola, M. enterolobii, M. hapla and M. daklakensis which belonged to genus Meloidgyne,
family Heteroderidae, suborder Tylenchina and order Tylenchida. Studies of investigating and
classification of root-knot nematodes in Vietnam were mainly based on morphological methods.
In 2005, identifying nematodes by molecular methods was first applied, but there was no results
of Meloidogyne identification. In 2012, M. graminicola and M. incognita were identified by
molecular methods. In 2018, Trinh et al. were identified new species called M. daklakensis based
on morphological characteristics, genes and mitochondrial ADN-based identification.
The study of root-knot nematodes was first published basing on biological characteristics of
M. arenaria parasitised on rice, M. incognita, relationship between M. incognita, Rotylenchulus
reniformis and Tylenchorhynchus brassicae and damage thresholds parasitised on tomato and
tobacco. However, there are not any reports about biological and ecological characteristics of
root-knot nematodes parasitised on eggplant.
220.127.116.11 Methods control root-knot nematodes
In Vietnam, the first report method to control of root-knot nematode was in 1981, followed
by reports about control methods for root-knot nematodes on black pepper and vegetable grown
in Ha Noi. Control methods of root-knot nematodes in Vietnam were also carried out basing on
the most popular methods on crops such as rice, tobacco, coffee, black pepper, Chinese cabbage
and salad. Control methods include crop rotation, resistant varieties, physical methods, biological
methods, chemical methods and integrated nematodes management. However, there have been
publishing methods to control root-knot nematode parasitised on eggplant in Vietnam as well as
CHAPTER 2. METHODOLOGY
2.1. Research time
Research period was from 2014 to 2017
2.2 Materials, equipments and instruments
Materials were eggplant variety of TN525 Green King; sandy clay (49% sand, 10% limon
and 41% clay) and clay (32% sand, 1% limon, 67% clay) and river sandy (70% sand, 20 % limon
and 10% clay); nylon bags and pots; organic amendments and Yara NPK fertilizer 15-15-15;
chemicals for specimens; sampling tools, sieve and laboratory equipment.
2.3 Research content
- Conducting to survey, collect samples, identify species composition, recognize symptoms,
to determine damage threshold and to observe density change of root-knot nematodes
(Meloidogyne spp.) in open field parasitised on eggplant in Lam Dong.
- Studying biological and ecological characteristics of M. incognita detected on eggplant in
- Studying methods to control root-knot nematodes (M. incognita) following integrated
- Building protocol of integrated nematodes management (M. incognita) parasitised on
eggplant in Lam Dong.
2.4 Research methods
2.4.1. Survey and identification of root-knot nematodes parasitised on eggplant in Lam Dong
Investigating farmers was carried out by interviewing directly with semi-structured
18.104.22.168 Investigation of the main nematodes parasitised on eggplant in the field
Samples were collected from 85 households. On the field, an random area was chosen about
100m2. Surveying from 5 points according to diagonal rules was to determine main pest and
diseases in open field based on typical symptoms on the stem, leaf, fruit of eggplant (Daunay,
(2008); Srinivasan (2009).
Soil and root samples were taken according to the W-pattern from 85 eggplant fields in Lam
Dong. Samples were stored in a thermostatic cabinet at a temperature of 15oC.
22.214.171.124 Extraction root-knot nematodes from soil and root samples
Activity second-stage juveniles were extracted from soil and root by modification
Baermann funel. The sample was incubated in the funnel for 48 hours at room temperature.
Activity second-stage juveniles were counted by stereo-microcopes with 4X magnification.
126.96.36.199 Determining the ratio of root damage and root gall-index
Root gall-index was assessed by the degree of infection from 1-10 according to Zeck (1971),
Bridge and Page (1980).
Determining the incidence of root knot nematodes
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑟𝑒𝑝𝑒𝑎𝑡 𝑓𝑖𝑒𝑙𝑑𝑠 𝑠𝑢𝑟𝑣𝑒𝑦𝑒𝑑
Incidence of root knot nematodes(%) =
𝑇𝑜𝑡𝑎𝑙 𝑓𝑖𝑒𝑙𝑑 𝑠𝑢𝑟𝑣𝑒𝑦𝑒𝑑
Determining the frequency of species occurrence
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑡𝑖𝑚𝑒𝑠 𝑒𝑛𝑐𝑜𝑢𝑛𝑡𝑒𝑟𝑒𝑑 𝑠𝑢𝑟𝑣𝑒𝑦
Frequency of species occurrence(%) =
𝑇𝑜𝑡𝑎𝑙 𝑜𝑓 𝑡𝑖𝑚𝑒𝑠 𝑠𝑢𝑟𝑣𝑒𝑦𝑒𝑑
Determining ratio of root infestation
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑟𝑜𝑜𝑡 𝑖𝑛𝑓𝑒𝑐𝑡𝑒𝑑
Ratio of root infestation (%) =
𝑇𝑜𝑡𝑎𝑙 𝑜𝑓 𝑟𝑜𝑜𝑡 𝑠𝑢𝑟𝑣𝑒𝑦𝑒𝑑
188.8.131.52 Extraction with perineal pattern females
Females of Meloidogyne were dissected out from the root galls by using forceps under
compound microscope and transferred 20 females to 0,9% NaCl.
184.108.40.206 Cut perineal patterns
Females were cut with a sharp knife and the body content was cleared away from the
internal surface of the cuticle. The cuticle of the posterior third of the body was trimmed down to
a small piece containing vulva, anus and tail tip. Perineal patterns were sealed with a coverslip
by nail varnish
220.127.116.11 Making specimens
How to make temporary and long-term specimens was been according to Bezooijen (2006)
and Ravichandra (2010).
18.104.22.168 Examinations of morphological features
Morphological features included the perineal pattern, stylet morphology, and distance from
the base of the stylet knobs to the dorsal esophageal gland, length of second-stage juveniles,
males, females by Bel-capture ruler.
22.214.171.124 Identification root-knot nematodes by molecular
Root-knot nematodes were identified by molecular basing on primer of tropical root-knot
2.4.2 Biological and ecological characteristics of root-knot nematodes (M. incognita) detected
126.96.36.199 Culturing and purifying species
Root-knot nematodes (M. incognita) were cultured and purified on tomato roots in B5Gamborg semi-liquid media.
188.8.131.52. Studying morphological and biological characteristics (life cycle, ratio of hatching of M.
incognita) in the laboratory
Morphology characteristics and development stages of M. incognita were observed at
temperature about 24±1oC with 3 different soil moisture at 30 - 40%, 40 - 50%, 50 - 60%. Roots
were stained to describe morphology characteristics and development stages. Roots were stained
by fuchsin acid. Ratio of hatching was determined by counting the number of the second-stage
juveniles formed on the total of hatching eggs in 3 different environments including distilled
water; extracts of 1-month eggplant roots; 6-month eggplant roots.
184.108.40.206 Studying ecological conditions affected to density of root knot nematodes
Preparing free-disease plants
Seeds are sterilized and sown on sterilized substrates in the greenhouse.
Nematode inoculation in pots in the greenhouse
The second-stage juveniles of M. incognita were extracted from tomato roots cultured in
the laboratory. Initial population of M. incognita was inoculated about 2000 individuals/pot.
Effect of soil moisture, rainfall, temperature on M. incognita in the field
The experiment was conducted in the open field grown eggplant TN 252 Green King variety
in Suoi Thong B village, Da Ron communes, Don Duong district in Lam Dong provine.
Secondary data of temperature and rainfall during 2014-2017 was collected from meteorological
stations of Thanh My, Don Duong and Da Lat. Soil moisture is determined by weigh method.
The density of the second-stage juveniles was determined a 30-day period during three continuous
seasons to assess correlation between the density of the second-stage juveniles of M. incognita
and rainfall, temperature and soil moisture.
Effects of soil conditions (particle composition and organic content in soil) on density
of root-knot nematodes
Analysis of soil texture
Analysis of soil texture was deternined according to Bouyoucos (1962) and named based
on soil triangle. Correlation of sand content and density of second-stage juveniles in the soil was
Effect of different organic amendments on root- knot nematodes M. incognita
parasitised on eggplant
Experiments were carried out in the green house. Meterials included organic amendments
such as chicken manure, pig manure, goat manure, cow manure, commercial organic fertilizer
and eggplant “TN252 Green King”. Comparison between the 5 treatments with control was
carried out, each repeated 3 times in clay pots. Root-knot nematodes (M. incognita) were
inoculated at 3 weeks planting. Soil and root samples were taken from 6 planting pots and mixed
to collect mixture samples. Experimental measures included density second-stages juveniles in
soil and roots, ratio of root galls, number of galls, flowers, fruits and eggplant yield.
Evaluation of eggplant varieties on root-knot nematodes
The experiment was carried out in pots, in sandy clay, including six eggplant varieties
including Thailand No.1, TN252 Green King, F1-033 local, black fruit NV123, Runako and Com
Xanh, repeated 3 times. Inovation second-stages juveniles of M. incognita after 3 weeks planting.
Soil and root samples were mixed from 6 pots to a mixture sample. Experimental measures were
density of the second-stages juveniles in soil and roots, root-gall index, number of flowers, fruits
and ratio of fruiting.
2.4.3 Control methods root-knot nematodes (Meloidogyne incognita) detected on eggplant
following by integrated nematodes management in Lam Dong
These experiments was conducted using eggplant ‘TN 252 Green King’ in the open field in
Da Ron, Don Duong in Lam Dong. The experiments were repeated 3 times. Planting density was
about 17,000 plants per hectare. Care and irrigation were the same in all treatments. Experimental
measures included density of the second-stage juveniles in soil at the time of 30 days, 60 days,
90 days planting and the end of harvesting; density of the second-stages juveniles in roots;
effective control of root-knot nematode calculated by Henderson - Tilton formula; ratio of root
infected, root gall index and eggplant yield.
220.127.116.11 Cultivation methods to control root-knot nematodes
Experimental treatments included: (i) crop rotation between eggplant with tung ho, cabbage,
chili peppers, sweet corn, (ii) intercropped with the common bean Phaseolus vulgaris and
18.104.22.168 Physical methods to control root-knot nematodes
Experimental treatments included: (i) soil solarization (after harvesting the previous crop,
plowing and drying the soil for 4 weeks); (ii) Keep soil dried (after harvesting the previous crop,
plowing, every 7 days upsetting soil, keep soil dry out and soil moisture lower than 35% in 4
weeks); (iii) Covered with dark plastic (after harvesting the previous crop, deep plowing at least
25cm, irrigating and covering by plastic for 4 weeks); (iv) Burning soil (after harvesting the
previous crop for 2 weeks, plowing the soil, making rows, covering a thin layer of 5-7cm husk
into the planting groove, then a layer of 5cm thick soil, burning anaerobic, irrigating to soil
moisture after 48 hours); and (v) Control (after harvesting the previous crop, did not using any
method in soil, keeping for 4 weeks, plowing soil and making row for ready to plant).
22.214.171.124 Biologicial methods to control root-knot nematodes
The experimental treatments included: Jianon Chitosan super (Chitosan); Vineem 1500 EC
(neem - azadirachtin); Abuna 15GR (saponin); Biosune one (Trichoderma harzianum,
Trichoderma viride and other microorganism) and control.
126.96.36.199 Chemiscial methods to control root-knot nematodes
The experimental treatments included: Tervigo 020SC (Abamectin), Cazinon 10GR
(Diazinon), Vifu-super 5GR (Carbosulfan), Map Logic 90WP (Clinoptilote) and control.
2.4.4 Building a model of control root-knot nematodes (Meloidogyne incognita) according to integrated
nematodes management detected on eggplant in Lam Dong
The previous crop was Tung Ho. After harvesting, cleaning the fields, plowing and drying
for 4 weeks, then making rows. Cow manure putting down with an amount of 40m3/ha were
incubated with 10 kg/ha probiotics containing T. harzianum. Irrigating and using plastic covered
on rows, keeping them for 7 days to allow fungi multiplied biomass rapidly, then planting after 7
days. After 10 days planting, eggplant was putted down chicken manure with amount of using
about 300kg/ha. The area of the model was 500 m2 compared to farmers' handling.
Evaluation of economic efficency of the model and control methods
Calculation of production costs included costs for fertilizers, pesticides and labor.
Calculating total income based on yield and price which was assumed about 2,000 VND per
kilogram (price assumed if profit was the lowest), the efficient economic was calculated as
Total income (thousand VND) = selling price per kg x yield
Total costs = cost of seed + cost of labor + cost of fertilizer + cost of plant protection + cost
Net income = Total income - Total costs
2.5 Data analysis
Data were collected and analysed of variance (ANOVA) by Microsoft Excel 2013 software,
IBM SPSS Statistics Version 22 software and MSTATC. The mean comparison was done through
LSD test and Duncan test with significance level of ≥95% (p≤0.05)
CHAPTER 3. RESEARCH RESULTS AND DISCUSSION
3.1 Cultivation methods and control nematode parasitited on eggplant of farmers in the studied
3.1.1 Survey of traditional cultivation of eggplant farmer in the studied area
Cultivation and control methods root-knot namtodes detected on eggplant of farmers in the
Table 3.1&3.3 The area and yield of eggplant varieties were grown widely in open field
(Lam Dong, 4/2014-6/2017)
(plants/ha) (tons/ha) level (%)
TN252 Green King
Oval fruit Japanese
Black fruit VN123
F1-033 local variety
There was 7 varieties planted in Lam Dong, TN252 Green King was the most planted
variety, accounting for 56.47% of the total, average yield was 92.72 tons/ha and density was
17,000 plants/ha, followed by the Runako variety accounted for 12.94% of total, average yield
was 35.90 tons/ha, density was 25,000 plants/ha. The lowest ratio belonged to Com xanh variety,
just only 1.18% and the yield was just about 35.00 tons/ha.
Only 34.11% farmers checked pest and disease status of nursery stock and only checked
the surface parts such as fungal disease on leaves or stems. If the nursery stock was not managed
soil well, crops would suffered from plant parasitic nematodes, then spread nematodes to the
The variety of TN252 Green King was the highest ratio of plant detected by nematodes
(79.16%), followed by Thai No.1 variety (71.43%), next to Runako (63.63%) and the lowest ratio
was the Com Xanh (0%, n = 1). Meanwhile, variety TN252 Green King showed the highest yield
losses (27.13%), variety Thailand No.1 (25.34%). Local variety and Com Xanh yield were
Soil treatment and eggplant parasitic nematode control methods of farmer
Table 3.4 Treatment of soil by farmers in Lam Dong (4/2014-6/2017)
Ratio application (%)
Only used lime
All surveyed farmers used lime before planting to treat soil for controlling pathogens and
some insects caused disease of eggplant, accounted for 100% for surveyed farmers. Chemical
methods were also commonly used, accounting for 62.35%. Commercial chemicals were used
such as Nokaph 10GR (30.82%), Map Logic 90WP (5.88%), Basudin 10% granular (8.0%) and
Binhtox 1.8EC (17.64%). Up to 67.06% of surveyed farmers used physical methods such as
fallow, did not plow, covering with dark nylon. Only 5.88% of surveyed farmers used biological
methods for controlling disease in soil. About 11.76% of surveyed farmers did not use any
treatment methods except liming. According to farmers, chemical methods were the most
effective brought the highest profits.
76.46% of surveyed farmers recognized symptoms of stunted plant, roots galls, low uptake
nutrition, they changed the ways to provide fertilizer for eggplant by diluting fertilizer then
irrigating directly to roots or spraying on the foliar instead of putting down into soil as before.
Only 5.88% of surveyed farmer using Tervigo 020SC sprayed on their roots to control root
Fertilizers used and feritilizer dosage used in eggplant cultivation
Table 3.6 Using fertilizer of eggplant farmers (Lam Dong, 4/2014-6/2017)
Ways to use
Scattering between rows
0.3 - 1.0 Every ten days
Scattering around root
Every ten days
Irrigating around root after 5
Every month, after Spraying on leaves after 6
0.1 - 0.2 Within 1 - 2 months Scattering around root
0.5 - 0.7 Once
before Scattering around root
0.1 - 0.2 Basal
fertilizer, Scattering around root and
Survey results show that 100% of eggplant farmers used organic fertilizers and NPK,
phosphate and potassium fertilizers. However, fertilizer types and dosage were different. Up to
94.11% of surveyed farmers used foliar and nitrogen fertilizers to put down for eggplant.
3.1.2 Symptoms and the major eggplant pests and diseases in Lam Dong
Common eggplant diseases included green wilt, Verticillium wilt, anthracnose and mosaic
disease. All diseases exposed symptoms on leaves, fruits, but none symptoms on roots and none
Eggplant insects included leaves and fruit insects and thrips palm. These insects damage on
leaves, stems and fruits of plants, but not detected in root system.
There were seven genus nematodes infected eggplant root system including
Helicotylenchus, Tylenchus, Meloidogyne, Criconemella, Pratylenchus, Rotylenchulus and
Longidorus. In which, Helicotylenchus were encountered with 100% of eggplant fields. Next,
genus of nematodes was Tylenchus, achieved 91.76%, following Meloidogyne with 83.52%.
Longidorus was the least parasitic nematode only 2.35%. The highest nematode density belonged
to Meloidogyne (667 individuals/50cm3 soil), followed by Helicotylenchus with 570
individuals/50cm3 soil. Density of Rotylenchulus was the lowest with only 16 individuals/50cm3.
This proved that root-knot nematodes played an important role for yield losses.
Typical symptom of root-knot nematodes was the appearance of numerous galls on the
roots. With the serious damage, galls were enlarged, even forming large swollen on the main
roots. Symptoms of root-knot nematodes above-ground were differently recognized, especially
when plants were young. When eggplant was 3-4-month age, root gall index was approximately
6, symptoms were recognized by stunted, yellow leaves, small and fewer fruits. Below-ground
symptoms exposed in the period of about 6-8 months after planting. This was the time that
eggplant have been ready for harvest, growth and resistance of the plant were reduced, root
system was old, less forming new roots and lower uptake nutrition.
3.1.3 Density of root -knot nematodes (Meloidogyne spp.) detected on eggplant in Lam Dong
Table 3.9 Second-juvenile stages density of Meloidogyne sp. in soil and roots and infestation
level (Lam Dong, 4/2014-6/2017)
Density of second-juvenile stages
Density of J2 in soil (individual/50cm in soil)
Density of J2 in roots (individual/5 g root)
Damage level according to farmer estimated (%)
Yield losses (%)
During the year, density of second-juvenile stages in soil was 1455 individuals/50cm3, in
roots was 728 individuals/5g of roots. In the dry season, nematodes density was lower than
average of year, the density of the second-juvenile stages was just only 827 individuals/50cm3 in
soil lower than 628 individuals/50cm3 in soil that of average year and 331 individuals/5 g roots
in roots lower than that of 397 individuals/5g in roots of average year.
Figure 3.12 Correlation between damage thresholds and yield crop (Lam Dong, 4/2014-6/2017)
Damage level of root knot nematodes was higher, eggplant yield losses was more, they have
been non-linear correlation according to the cubic equation (y = 0.02 + 3.09x-2.41x2 + 0, 49x3).
In eggplant field, if root gall index of root knot nematode was 1-3, the yield would be not reduced.
When symptoms of root-knot were recognized visibly on roots such as stunting, fertilizer was
used much higher, flowers and fruits would be reduced, yield losses would be higher. Meanwhile,
eggplant roots were more than 60% of root galls, approximately 6 root-gall index, estimated yield
losses up to 40 - 50%.
Density of the second-stage juveniles of root-knot nematodes in soil ranged from 500
individuals/50cm3 to 1500 individuals/50cm3 in soil. In the 71 surveyed samples, there were 6
soil samples with density of second-stage juveniles ranged of 2000 - 3000 individuals/50cm3, 4
soil samples with density higher than 3000 individuals/50cm3.
3.1.4 Surveying, collecting and identifying root-knot nematodes (Meloidogyne spp.) detected
The surveyed results showed that, root-knot nematodes were detected in the 83.52% of the
soil and root samples collected. There were 2 species presented in the 71 soil and root samples.
Morphological characteristics were described. 48 out of 71 collected samples were the same
morphological characteristics of Meloidogyne incognita, 17 out of 71 collected samples were the
same species of M. javanica, 6 samples were occurred mixture of the two species.
Figure 3.18 The frequency of Meloidogyne species (percentage) in Lam Dong (4/2014 - 6/2017)
The surveyed results of root-knot nematodes species showed that occurence of M. incognita
was 67.71%, followed by M. Javanica, accounted to 23.94% and mixture of the two species only
Table 3.12 Incidence of root knot nematodes, root gall index and density of root-knot
nematodes detected on eggplant (Lam Dong, 4/2014-6/2017)
Location study Incidence
Root gall Density of J2 Root-knot nematodes species
M. incognita, M. javanica
M. incognita, M. javanica
M. incognita, M. javanica
In of three studied location, the highest incidence of root-knot nematodes was in Don Duong
(84.85%), the lowest was in Da Lat (only 60%). The density of second-stage juveniles in soil and
root gall index were the highest in Don Duong, with 789 individuals/50cm3 and 4.91, respectively,
otherwise, the lowest figures were in Da Lat, proved by 356 individuals/50cm3 and 3.12
respectively. All of three studied areas, two species occurred were M. incognita and M. javanica,
but infectious fields in Don Duong and Duc Trong with the mixtures of M. incognita and M.
javanica was higher than that in Da Lat.
Identification results showed that DNA samples were suitable for M. ethiopica, M.
arenaria, M. enterolobii and M. javanica on eggplant. 4 samples were acceptable Mi2F4/Mi1R
primers, M. incognita were identified.
Generally, 71 out of 85 collected samples were found Meloidogyne species with M.
incognita and M. javanica. Out of two, M. incognita was more frequent played an important
damage role with 67.61%, M. javanica was lower frequent with 23.94%. Mixture of them was
3.2 Biological and ecological characteristics of Meloidogyne incognita
3.2.1 Morphological characteristics of Meloidogyne incognita
Life cycle of M. incognita undergwent the first moult in the eggs to develop to the firststage juveniles (J1) to the second-stage juveniles (J2) to third-stage juveniles (J3) to fourth-stage
juveniles (J4) then to mature stage (adult females and males). Specific characteristics of them
were showed as follows:
Eggs: Egg shape was oval, contained in egg mass of the female. Eggs were laid by females
and usually found on the surface of galled roots sometimes inside plant tissue.
The first-stage juveniles: embryogenesis proceeds to the first-stage juveniles with a blunt
tail tip, vermiform, curl up which mounted one in the egg. Then, they developed to second-stage
juveniles depended on environmental condition.
The second-stage juveniles: Second-stage juveniles of M. incognita were movable
vermiform, tapered head with stylet. The tail part is transparent.
The third-stage juveniles: Under favorable environment, J2 hatched in roots to J3 which
were tapered at the end of tails, bulged in the middle. Their head were without stylet, short tail.
The fourth-stage juveniles: They were avocado shape, lack a functional stylet, short - small
clear tail. They did not feed.
Females: Adult females were pear shape, sedentary, head with stylet, feed roots.
Males: Male were mobile, remain vermiform, leaved galls and entered soil. They have
spicules at the end of the tail. Stylet of male is blunt, set off.
Table 3.13 Size of some stages of M. incognita
Width (µm) Stylet length (µm) DEGO (µm)
Note: DEGO (dorsal esophageal gland orifice)
Morphology of M. incognita has undergone different stages of development. Egg stage was
the smallest size. The second-stage juveniles, females and males were significant differences
length, width, tail, stylet and dorsal esophageal gland orifice (DEGO). The second-stage juveniles
and males were vermiform, but the length of males was over 5 times than that of the second-stage
juveniles, males stylet was over 2.5 times than that of the second-stage juveniles, DEGO of males
was lower than that of the second-stage juveniles. Females length was shorter than that of males,
longer than that of the second-stage juveniles.
3.2.2. Biological characteristics of Meloidogyne incognita
188.8.131.52 Life cycle, characteristics of the sexual phases of M. incognita
Life cycle of M. incognita started the second-stage juveniles infected into root, underwent
some moults such as the third-stage juvenile, the fourth stage juveniles and adults, then hatched
a new infectious second-stage juveniles when its life cycle completed.
Table 3.14 Development time and ratio of root inoculom of the second-stage juveniles
Development time (days)
Ratio of root
Development time of the second-stage juveniles in eggplant roots averaged 8.01 days and
there was no difference between different moisture thresholds. Ratio of root inoculum of the
second-stage juvenile was different at three soil moisture thresholds. At the average soil moisture
(36.13%), ratio of root inoculum of the second-stage juveniles was the lowest, only 85.68%, the
highest at the soil moisture of 46.77% reaching 95.46%, soil moisture of 57.11% achieved
Table 3.20 Life cylce of M. incognita
Time of development stage (days)
Experiment 1 Experiment 2 Experiment 3
Egg and first-stage juveniles
Temperature ( C)
Soil moiture (%)
In three different soil moisture at 36.13%, 46.77% and 57.11%, the average development
time of the third-stage juveniles was 3.98 days, the fourth-stage juvenile was only 2.13 days, adult
female was 8.02 days. Time of development from fourth-stage juveniles to male was 19.25, there
was not significant difference among 3 different soil moisture.
Life cycle of the M. incognita root knot nematode was 27.16 days at temperature at 24±1oC
and soil moisture at 46.67%. The development time of M. incognita did not differ significantly
between 3 different soil moisture. Development time of the second-stage juveniles and females
were the longest with 8.03 and 8.02 days, respectively. Development time of the fourth-stage
juveniles was the shortest with only 2.13 days, followed by the third-stage juveniles was 3.98
days while eggs and the first-stage juveniles was for 5 days. Development time from the fourthstage juveniles to males was 19.25 days. Time from the second-stage juveniles to males at
conditions of 24oC ± 1oC, 46.67% was 33.39 days.
184.108.40.206 Ratio of hatching egg of M. incognita
Table 3.21 Effect of environment condition to ratio of eggs hatch of M. incognita
Environment for eggs hatch
Ratio of hatching (%)
Root extraction of one-month root
Root extraction of over-month root
The eggs hatch ratio of M. incognita was the highest in extract of one-month eggplant roots,
reaching 90.72%, followed by in extract of six-month eggplant roots with 83.00% and much
higher than that of distilled water with only 69.30%.
3.2.3 Effect of ecological conditions on Meloidogyne incognita
220.127.116.11. Effect of soil texture on density of the second-stage juveniles in soil
Table 3.22 Effect of soil-particle on the second-stage juveniles detected on eggplant in
Lam Dong (4/2014-6/2017)
Clay content Limon content Sand content (%) Soil types
Density of J2
Silty clay loam
Correlattion (r) between of sand and J2
Soil types affected differently on density of the second-stage juveniles. While clay and
limon content were not correlated with density of second-stage juveniles in soil, sand content was
correlated with density of the second-stage juveniles. Out of all soil types, density of the secondstage juveniles in clay was the lowest, average of 222 individuals/50cm3 in soil, followed by silty
clay with average density of 365 individuals/50cm3 in soil, silty loam with 513 individuals/50cm3
in soil. Density of the second-stage juveniles in sand loam was the highest, achieved 1735
individuals/50cm3. Density of the second-stage juveniles in loam was lower than in sand but
higher than in clay.
18.104.22.168. Effect of rainfall, air temperature and soil moisture on M. incognita in soil grown
eggplant in Lam Dong
Table 3.23 Correlation between soil moisture, air temperature and rainfall to the density of M.
incognita in Lam Dong (6/2014-5/2017)
Density of J2
Soil moisture Rainfall Temperature
Density of r
Sig. (two ways
Sig. (two ways
Sig. (two ways
Sig. (two ways
*. Correlation at p= 0.05 (two ways factor)
**. Correlation p=0.01 (two ways factor)
There was a close linear correlation between three factors: rainfall, soil moisture and
temperature and also between these factors and the density of the second-stage juveniles in soil.
Rainfall and soil moisture have a very close correlation (r = 0.812). Soil moisture, rainfall are
correlated with density of the second-stage juveniles in the soil (0.5
0.678, respectively. Soil moisture and rainfall were close correlation with density of the secondstage juveniles in soil. The results proved that soil moisture and rainfall affected on density of
second-stage juveniles of root-knot nematodses in soil.
22.214.171.124 Density variation of M. incognita in a growing season of eggplant in Lam Dong
Figure 3.33 Density of the second-stage juveniles of M. incognita in a growing season of
eggplant in Lam Dong (crop 2015 - 2017)
At 30 days before planting, density of M. incognita was low only 225 individuals/50 cm3 in
soil, but then, at the time of planting, density of second-stage juveniles increased. They increased
fastly at 30 days and 60 days after planting, achieved 3051 and 2975 individuals/50cm3 in soil,
respectively. Then, density of root knot nematodes decreased sharply, tended to stabilize at 90
days, 120 days and 150 days after planting. 180 days after planting, density of M. incognita in
soil gradually decreased. At the end of the crop, density of root-knot nematodes in soil is reduced
to 476 individuals/50cm3.
126.96.36.199 Effect of different organic amendment on root knot nematodes detected on eggplant
Table 3.24 Effect of organic amendment on the second-stage juveniles (J2) M. incognita in soil,
roots, root knot nematodes, ratio and number of galls detected on eggplant (Lam Dong, 20142015)
Density of J2
Density of J2 in Ratio of root
Organic fertilizer (%)
Density of second-stage juveniles of M. incognita in soil was the lowest in cow manure
treatment (1360 individuals/50cm3 soil), followed by chicken manure (1634 individuals 50cm3
soil), organic fertilizer 73% (1825 individuals/50cm3 soil), goat manure (1859 individuals/50cm3
soil) and the highest density of second-stage juveniles was in pig manure treatment (2967
individuals/50cm3 soil). In roots, density of second-stage juveniles was the lowest in chicken
manure treatment (266 individuals/5g roots) and commercial organic fertilizer 73% organic
content (309 individuals/5g roots). Ratio of root infestation in chicken manure treatment and
organic fertilizer treatment were significant difference from other treatments. Number of root
infestation was the highest in the control (22.67 galls/root) and significant difference from in pig
manure (18.67 galls/root), goat manure (15.67 nodules/roots) and cow dung (19.00 notes/root).
number of galls in chicken manure treatment and commercial organic fertilizer treatment were
the lowest, not statisticial difference, only 7.67 galls/root and 8.67 galls/roots, respectively.
188.8.131.52 The reaction of eggplant varieties with root knot nematodes
Table 3.25 Density of the second-stage juveniles of M. incognita in soil (Lam Dong, 2017)
Density of second-stage juveniles in soil (individuals/50cm3 soil)
Inoculated 20 NSN 40 NSN 80 NSN
100 NSN ED
Thai Lan No.1
TN 252 Green king
F1-033 local variety 2000
Black fruit NV123
Note: NSN: days after inoculating; ED: end of crop.
Second-stage juveniles density decreased at 20 days after inoculating and increased at 40
days, 80 days, 100 days after inoculating. Density of the second-stage juveniles in soil was highest
in TN252 Green King, followed in Thai No.1, balck fruit NV123. It was the lowest in Runako
and Com Xanh.
Table 3.26 & 3.27 Density of M. incognita in roots, infestation level at 150 days after
inoculation, number of flowers, fruits and proportion of fruiting (Lam Dong, 2017)
Density of J2 in root
Root gall Flowers Number
of fruits fruiting (%)
Thai Lan No.1
TN 252 Green king
F1-033 local variety
4.00 b 15.67 b 11.67 b
Balck fruit NV123
5.67 a 13.67 b 10.00 b
5.67 a 22.67 a 16.67 a
Density of M. incognita in roots and root galls index in F1-033 local varieties were the
lowest. Otherwise, density of second-stage juveniles in roots and root galls index in TN252 Green
King were the highest but not significant difference from Thai Lan No.1. The highest flowers in
Runako (22.67 flowers/plant) was not significant difference, compared to TN252 Green King
(18.00 flowers/plant). The average numbers of fruits in Runako was also the highest (16.67
fruits/plant) completely different from other varieties. Ratio of fruiting of Com Xanh (79.04%),
Thailand No.1 (78.11%), local variety (76.79%) and Runako (75.68%) were higher than that of
TN252 Green King.
3.3 Integrated nematodes management of root knot nematode in open field
3.3.1 Cultivation methods to control root knot nematode detected on eggplant
Table 3.28 Effect of cultivation methods on density of second-stage juveniles of M. incognita
detected on eggplant in Lam Dong (2014-2016)
Density of second-stage juveniles
in soil (individuals/50cm3)
60N 90N ED
Rotation with Tung Ho 631 607 689
816 462 5.73
22.71 34.03 6.82a
Rotation with Chinese 822 767 1015 1927 590 8.56
12.60d -19.59d 4.46c
Rotation with chili 630 975 1067 1601 441 -51.65e -19.88e -29.64e 2.54d
with 805 624 922
1420 576 24.04a 18.93b 10.01c 4.75b
Rotation with sweet 958 762 1164 1261 686 22.06b 14.00c 32.85b 4.69b
780 796 1102 1529 586 LSD0,05
0.765 0.765 0.399 0.2113
Note: TT: before planting; N: days after planting; ED: end of crop
Density of second-stage juveniles in soil in most of experimental treatments decreased
dramatically at 30 days after planting, increased at 60 days and at 90 days after planting then
decreased at the end of harvest. Rotation eggplant with different crops showed that density of the
second-stage juveniles in soil decreased significantly at 30 days planting. The highest efficiency
in Tung Ho treatment was 34.03%, followed by sweet corn reaching 32.85% and intercropping
with French beans 24.04%. Crop rotation of eggplant with chlili pepper has negative efficiency
at 30 days, 60 days and 90 days planting. The results indicated that rotation eggplant with chili
peppers was not effective for control root-knot nematodes (M. incogonita) detected eggplant.
Bảng 3.29. Effect of cultivation methods on root infection of root knot nematode detected
eggplant in Lam Dong (2014-2016)
Density of J2 in root
Ratio of root
Rotation with Tung Ho
Rotation with Chinese
Rotation with chlili
Intercroping with French
Rotation sweet corn
Density of second-stage juveniles in roots was the highest in rotation between chili pepper
treatment and eggplant (1136 individuals/5g roots), decreased slightly to 1111 individuals/5g
roots in specializing eggplant treatment, the lowest figure belonged to rotation between Tung Ho
and eggplant (498 individuals/5g roots). The ratio of root infestation and root gall index were the
lowest in the rotation between Tung Ho and eggplant with 37.13% and 2.67, respectively.
Summary, the rotation eggplant with Tung Ho reduced density of root knot nematodes in
roots, ratio of root infestation, root gall index and increased yield of eggplant, followed by
intercropping with French beans, rotation with sweet corn and Chinese cabbage. Rotation
between chili peppers and eggplant and specializing eggplant increased ratio of root infestation,
root gall index and reduced eggplant yield.
3.3.2. Physical methods for control root-knot nematodes dettected on eggplant
Table 3.30 Effect of physical methods on density of M. incognita detected on eggplant in Lam
Dong (2014 - 2015)
Density of second-stage juveniles in
TXL 30N 60N
1232 1315 1667 2560 1164 3.15
Keeping soil dried 1321 1086 1862 2723 1195 25.40c 0.06c
Covering plastic 1329 902 1617 2858 1175 38.41b 13.73a 0.74b 10.54a
1389 760 1883 2996 1370 50.35a 3.88b
1116 1230 1574 2418 1103 LSD0,05
Note: TXL: before applying; N: days after applying; ED: end of crop
The density of the second-stage juveniles in soil decreased at 30 days planting, then
increased at 60 days and 90 days planting and fell sharply at the end of the crop. After 30 days of
treatment, the most efficiency of root knot nematodes was in burning method, reaching 50.35%,
followed by covering plastic, reaching 38.41%. The lowest efficiency was in soil solarization
Table 3.31 Density of second-stage juveniles (M. incognita) in root, ratio of root infestation,
root gall index and eggplant yield in lam Dong (2014-2015)
Density of J2 Ratio of root
Root gall index Yield
Keeping soil dried
Density of the second-stage juveniles in roots was the highest in covering plastic treatment
and control, 758 individuals/5g roots and 735 individuals/5g roots, respectively. The figure was
the lowest in burning treatment (484 individuals/5g roots), different from soil solarization (611
individuals/5g roots) and keeping soil dried (512 individuals/5g roots). The ratio of root
infestation and root gall index of control and covering plastic treatment were higher than that of
burning and soil solarization. Yield of using burning method (98.33 tons/ha) was lower than
keeping soil dried (103.30 tons/ha and control (103.30 tons/ha).
3.5.3 Biological methods to control root-knot nematodes detected on eggplant
Table 3.32 Effect of biological methods on density of root-knot nematodes detected on eggplant
in Lam Dong (2014-2015)
Density of J2 in soil (individuals/50cm3)
60N 90N ED
-17.40 41.77 -108.75
42.97 66.36 32.30
1088 -168.28 29.91 44.21 -9.61
56.71 21.39 -40.34
23,77 26.89 -1.01
Note: TXL: before treatment; N: days after applying; ED: end of crop
Density of M. incognita decreased at 30 days, 60 days and 90 days after applying in all
treatments comparing to the control. Efficiency of Jianon chitosan super and Abunar 15GR
treatment were negative efficiency after 30 days applying and the end of harvetsing. The highest
effective methods to control of root-knot nematodes was in Vineem after 90 days applying,
achieved 66.36%, next Biosun one after 60 days treatment (56.71%), then bio-fumigation (43 ,
69%) after 30 days processing.
Table 3.33 Effect of biological methods on density of the second-stage juveniles in roots,
ratio of root infestation, root gall index and yield of eggplant in Lam Dong (2014-2015)
Density of J2 in roots Ratio of root gall
(individuals/5 g root)
Density of the second-stage juveniles (M. incognita) in eggplant roots was the highest in
control (2004 individuals/5g roots), followed by Jianon chitosan super treatment (1596
individuals/5g roots), Abuna 15GR (1400 individuals/5g roots). The lowest density of secondstage juveniles was in Vineem (796 individuals/5g roots) and biofumigation (874 individuals/5g
roots). Ratio of root infestationand and root galls index in biofumigation treatment were the
lowest, 53.61% and 5.00, respectively. These figures of control were the highest up to 78.03%
and 7.67, respectively. While yield of eggplant in Jianon chitosan reached the highest value
(108.00 tons/ha), followed by Vineem (102.70 tons/ha), the lowest in Abuna 15 GR only 92.00
3.3.4 Chemical methods to control root-knot nematodes detected on eggplant
Table 3.34 Effect of chemical methods on density of root-knot nematodes detected on eggplant
in Lam Dong (2014-2015)
Density of J2 in soil (individuals
33.19b -38.49c -31.37c -52.57c
13.35c -43.39c -50.64d -72.19d
Experimental results show that density of M. incognita in eggplant field during 2014-2015
decreased grammatically after 30 days applying then increase dramatically after 60 days, 90 days
planting and at the end of the harvesting. All experimental treatments were effective to control
root-knot nematodes after 30 days treatment but efficiency was not extended from 60 days to the
end of harvest. Efficiency of Tervigo 020SC was higher than that of Map Logic 90WP and Vifusuper 5 GR.
Table 3.35 Effect of chemical methods on density of second-stage juveniles in roots, ratio of
root infestation, root gall index and yield of eggplant in Lam Dong ( 2014-2015)
Density of J2 in roots
Ratio of root
(individuals/5 g root)
Density of the second-stage juveniles of M. incognita was highest in Vifu-super (1184
individuals/5g roots), followed by control (1012 individuals/5g roots). That value was the lowest
in Tervigo treatment (541 individual/5g roots). Ratio of root infestation the Tervigo was the
lowest, only 38.27%, different from all of treatments. Root gall index was the highest in control
(7.33). The lowest root gall index was in Tervigo, only 3.68. Eggplant yield was the highest in
Tervigo (104.00 tons/ha) higher than that of control (95.67 tons/ha), Map logic (88.33 tons/ha)
and Vifu-super (88.67 tons/ha).
Generally, in all of methods to control root-knot nematodes (M. incognita), the most
effective method was biological methods, followed by physical methods, chemical methods and
the lowest effective was cultivation methods. Biological methods, physical methods and
cultivation methods were effective to control root-knot nematodes without affecting environment
and humans, safety and low-cost. Therefore, this study tended to use integrated nematode
management by combination between cultivation, physical and biological methods to control
root-knot nematodes in 2 models in Don Duong and Duc Trong in Lam Dong province.
3.4. Solutions to control root knot nematodes (Meloidogyne incognita) on detected eggplant
towards integrated management in Lam Dong
3.4.1 Effect of total management solutions to control of root-knot nematodes on nematode
population density M. incognita
Table 3.36 Density of second-stage juveniles of M. incognita and efficiency in Lam Dong
Density of J2 in soil (individuals/50cm3)
Don Duong 1031
36.68 66.63 30.01 24.50
Duc Trong 859
35.13 58.55 26.68 18.47
Density of second-stage juveniles in soil in two models decreased rapidly after 30 days and
60 days applying, lower than that in control. Efficiency in both models was high, reached 66.63%
in Don Duong and 58.55% in Duc Trong after 60 days applying. Efficiency to control root knot
nematode extended from the beginning to the end of crop.
3.4.2 Effects of integrated nematode management on density of root-knot nematodes in roots,
ratio of root gall, root gall index and yield of eggplant
Density of root-knot nematodes in roots, root infestation, root gall index in both models
were lower than that in control. Density of the second juveniles of M. incognita in roots of both
models in Don Duong and Duc Trong were lower than that in control, proved by 107
individuals/5g roots, 218 individuals/5g roots, respectively.
Table 3.37 Effect of integrated nematode management on root damage and yield of eggplant in
Lam Dong (2016-2017)
Density of root-knot nematodes
Ratio of root
(individuals/5 g root)
Ratio of root infestation in the model of Don Duong (12.53%) and Duc Trong (22.68%)
were low compared to the control of Don Duong (37.32%) and Duc Trong (41.51%). Root gall
index of eggplant roots in Don Duong model (1.93) and Duc Trong model (2.28) were lower than
that in both controls. Eggplant yield in both models was also higher than that in the control,
reached the highest with 116.33 tons/ha in Don Duong model, higher than 24.66 tons/ha
compared to the control model.
3.4.3 Economic efficiency of the model
Table 3.38 Economic efficiency of integrated nematode management to control root-knot
nematodes on eggplant in Lam Dong (2016-2017)
It is estimated that yield of the model increased, net income of models was higher than
traditional method application to control root-knot nematodes. Model applied integrated
nematode management in Don Duong, the net income was achieved 107,240 thousand VND
(107,240,000 VND/ha) higher 49,600,000 VND/ha compared to the control. The model in Duc
Trong was higher 33,600 thousand VND (33,600,000 VND/ha) compared to the control. The
results show that economic efficiency of application of integrated nematode management was
higher than that of farmers’application.
Generally, application of integrated nematode management on eggplant to control root-knot
nematodes was reduced root gall index, increased yield compared to farmers control methods.
CONCLUSIONS AND RECOMMENDATIONS
1. In this study two species of root-knot nematode parasitised on eggplant including M.
incognita and M. javanica were identified. M. incognita was more common species,
accounting for 67.61% while M. javanica accounted for 23.94% and mixture of two species
made of 8.45%.
2. Life cycle of M. incognita culturing on eggplant root in sandy (70% sand, 20% limon,
10% clay) at temperature 24 ± 1oC was 27.16 days. At the humidity threshold of 46.77%, the
inoculation level of second-stage juveniles into eggplant roots reached 95.46%, higher than that
at humidity threshold of 57.11% (93.31%) and 36.13% (85.68%). Ratio of second-stage
juveniles of M. incognita hatched from egg was highest in the extract of one-month eggplant
roots (90.72%), higher than in the extract of six-months eggplants roots while the lowest ratio
was in distilled water (69.30%). .
3. Sand content, soil moisture and rainfall had strong correlation with the density of
second-stage juveniles in soil. The density of second-stage juveniles increased proportionally
with the sand content. Density of M. incognita increased in rainfall from 0 to 160mm/month and
soil moisture ranging from 30 to 55%, otherwise, density of M. incognita decreased
proportionally with rainfall over than 160mm/month and humidity over 55%. Chicken manure,
organic fertilizer declined density of M. incognita detected on eggplant. Eggplant TN252 Green
King was the most susceptible by M. incognita.
4. Integrated nematodes management to control root-knot nematodes: Rotation between
eggplant and Tung Ho was the most effective cultivation methods with efficiency of M. incognita
reached 34.03%, ratio of root infestation (37.13%), root gall index (2.67). While burning was the
most effective in physical methods to control root-knot nematodes with efficiency achieved