BIBLIOGRAPHY IGUALDO, JIRLDANMYR...
BIBLIOGRAPHY
IGUALDO, JIRLDANMYR DIONISIO D. APRIL 2011. Field Efficacy
Evaluation of Nucleopolyhedrovirus Against Common Cutworm (Spodoptera litura
Fabr.) on Head Cabbage in Buguias, Benguet. Benguet State University, La Trinidad,
Benguet.
Adviser: Eulogio V. Cardona, Jr., PhD.
ABSTRACT
The study was conducted at Buyacaoan, Buguias, Benguet from July to
November 2010 to determine the number of Spodoptera litura Nucleopolyhedrovirus
(SINPV) larvae effective against healthy common cutworm larvae, and to determine
should SINPV has harm effect on adult Diadegma, a natural enemy of diamondback
moth.
Thirty early second instar healthy cutworm larvae were released on the cabbage
plants enclosed with nets and sprayed with the treatments which are as follows; 5, 10, 15,
20 SINPV larvae/ 16 li water. Selecron 50 EC at the rate of 3 TBSP/16 li water was the
standard insecticide. As basis for comparison, untreated cutworm larvae were included.
The mortality of cutworm larvae on the standard treatment of Selecron was the
highest equivalent to 76.67%, 71.11% on the SINPV treatment of 20 larvae/16 li water,
67.78% on the treatment of 15 SINPV larvae/16 li water and 36.67% on the treatment of
10 SINPV larvae/16 li water. The treatment of 5 SINPV larvae/16 li water has the lowest
level of mortality equivalent to 28.89%.
The treatments sprayed with the rate of 20 and 15 SINPV larvae/16 li water were
slightly damaged similar with the standard treatment of Selecron. The lower rates of
SINPV applied were moderately damaged.
The two highest rates of SINPV treatments at 15 to 20 larvae/16 li water had the
highest percentage of marketable yield equivalent to 83.00 and 89.67% comparable with
the standard treatment of Selecron which was 91.67%. The marketable yield decreased
significantly as the rates was reduced to 5 and 10 SINPV larvae/16 li water.
Mortality of adult Diadegma was not noted in all the SINPV treatments similar
with the untreated but mortality of 100% was recorded from the standard treatment of
Selecron.
It is concluded that SINPV at the rate of 20 and 15 larvae/16 li water has the
efficacy against cutworm of cabbage comparable to Selecron 50 EC. SINPV is not toxic
to adult Diadegma. SINPV is recommended for the control of cutworm in cabbage.
ii
TABLE OF CONTENTS
Page
Bibliography……………………………………………………………………….
i
Abstract …………………………………………………………………………...
i
Table of Contents ………………………………………………………………… iii
INTRODUCTION ………………………………………………………………...
1
REVIEW OF LITERATURE ……………………………………………..............
3
MATERIALS AND METHODS …………………………………………………
6
Toxicity of SNPV Against
Cutworm Larvae ………………………………………………………….
6
Toxicity of SINPV on Diadegma ………………………………………… 10
RESULTS AND DISCUSSION ………………………………………………….
12
Mortality Action of the Treatments ………………………………………
12
Effects of the SINPV Treatments ………………………………………...
13
Degree of Cutworm Damage ……………………………………………..
16
Marketable Yield (%) …………………………………………………….
17
Mortality (%) on Adult Diadegma ………………………………………. 18
SUMMARY, CONCLUSION AND RECOMMENDATION …………………..
19
LITERATURE CITED …………………………………………………………..
21
APPENDICES ………………………………………………………………….
23
1
INTRODUCTION
Common cutworm (Spodoptera litura Fabr.) is classified to belong to the order
Lepidoptera; Family Noctuidae. It is one of the primary problems of the majority of
vegetable growers. Cutworms have a very powerful mandible and this is use in damaging
cabbage by cutting the stem and chewing the leaves. In the Philippines, the insect infests
28 agricultural crops. Aside for cabbage and related crucifers, other crops infested by the
insect are tobacco in Ilocos region, onion in Nueva Ecija, peanut in Isabela, and beans
and rice in many parts of the country (Gabriel, 1997).
In Benguet Province like in other parts of the country, cutworm is a serious
problem. It is a problem in most semi-temperate leafy vegetables particularly cabbage.
Chemical insecticide is the usual practice of controlling cutworms. But with the many
disadvantages associated with its use, an environment-friendly method of controlling
cutworms like Spodoptera litura Nucleopolyhedrovirus (SINPV) is one of the possible
alternatives.
Microbial control or the use of viruses has been identified as both viable and
promising alternative for the chemical control of cutworms. Local strains of the
nucleopolyhedrovirus or cutworm have already been isolated and laboratory tested
(Padua et al., 1999).
One of the microbial pathogens with insecticidal activity against cutworm is
Nucleopolyhedrovirus (NPV). Studies for the efficacy of NPV against cutworm are many
especially in the lowland areas. For example, in the study of Agsaoay in 1998, NPV was
proven effective against cutworm of peanut and in asparagus as reported by Padua
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
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(1999). It was likewise mentioned by Navasero and Navasero (2002) that NPV was
effective against cutworm in egg plants. NPV are likewise cheap, environment friendly
and harmless to human. But in some places here in Benguet especially in Buguias, the
efficacy of SINPV was not yet tested.
The study aimed to determine the number of Spodoptera litura
Nucleopolyhedrovirus (SINPV) larvae effective against healthy common cutworm larvae,
and to determine should SINPV has harm effect on adult Diadegma, the natural enemy of
diamondback moth.
The study was conducted at Buyacaoan, Buguias, Benguet from July to
November 2010.
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
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REVIEW OF LITERATURE
Biology of Cutworm
Miyahara et al. (1971), Rao et al. (1989), Schmutter (1969), Baker and Miller
(1974) stated that female Spodoptera litura laid egg masses with around 1000-2000 eggs
per mass. The eggs are spherical, somewhat flattened, 0.6mm in diameter and covered
with hair like scales. Usually, it is pale orange, brown or white to dull or off-white in
color. They hatch in about 4 days in warm conditions or 11-12 days in winter times.
During the dry seasons of 1995, IDM-CRSP gathered data on the major and minor
insect pests and their natural enemies on rice vegetable system. Results of these efforts
have led to the identification of S. litura (Fabr). As one of the pest of onion, common
cutworm is one among the most economically important insect pests in the country. The
newly emerged larvae gregariously feed on the soft leaf tissues. The damage done by this
pest is exhibited by large feeding holes on the blades of mature and young leaves (Padua
et al., 1999).
Nature of Cutworm Damage
Cabbage is one of the vegetables attacked by S. litura. The insect damage the
stems, consuming the whole seedling, chewing the leaves of the plants in the open fields
causing irregular holes and boring the developing heads with lace of larval excrements. If
not controlled, the insect can reduce yield to as high as 50% to 100% (Cardona et al.,
2007).
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
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Microbial Control of Cutworm
Van Huis (1989) reported a number of entomopathogenic microorganisms (e.g.,
bacteria, fungi, protozoa, nematodes, and viruses) which are potential components in
insect pest management like the NVP. Studies revealed that these entomogenous
microbial agents can be potent instruments in reducing insect pest populations below
economic threshold. Insect viruses and bacteria in particular have appreciably shown
evidences as pest suppressive agents that could complement other control measures.
Pathogenicity and Toxicity test for SINPV
Ignoffo and Hiempel (1965) exposed guinea pigs and white mice to NPV of
Heliothiz zea (Boddie) and H. virescens (Fabricius) to test the pathogenicity and toxicity
of NPV. The virus was administered in the form of poly-inclusion bodies, free virus rods
or polyhedral protein through inhalation and feeding. Intravenous, intradermal,
intraperitoneal and intercerebral injections of the virus were also done. Except for one
pneumonia-caused death, all the test animals showed normal weight gains. Also, no
abnormalities were observed.
Podgwaite et al. (1979) estimated infectious Lymantria dispar NPV naturally
occurring in leaf, bark, litter, and soil. Concentrations of the virus were then compared
with the concentrations of the virus taken after NPV treatment of these plots. These
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
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comparisons revealed that NPV is a natural component of the host’s habitat and that
further NPV application did not cause an increase in NPV load.
Jaques (1967) evaluated the persistence of NPV in soil. Soil samples of 6.4 x
1010- treated plots contained 25% of the original infective virus after 5 years. A similar
rate of decline in viral activity was noted in soils exposed to artificial conditions.
Lavina et al. (2000) reported that S. litura NPV is a unique and distinct isolate;
further finger printing of the virus is currently being undertaken.
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
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MATERIALS AND METHODS
Toxicity of SINPV Against Cutworm Larvae
Site Selection
The study was conducted at Buyacaoan, Buguias, Benguet, a place in Buguias
where cabbage is widely planted and where the insect cutworm is one of the most
injurious pest’s insect. The research area were cleaned by the used of sickle and grab hoe.
Plot making and chicken dung application were done before the one month old seedlings
of the cabbage Scorpio variety were planted.
Preparation and Maintenance of Cabbage
Plants preparation was started by soaking the cabbage seeds for twenty four hours
before seeding on plots. After four weeks of care and maintenance of the seedlings, they
were transplanted in the study area. The application of the recommended rate of urea (46-
0-0) and complete (14-14-14) were done during the early vegetative stage to improve the
vigor of the plants and becomes more ideal for research purposes. Likewise, fungicide
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
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was applied to prevent buildup of diseases. In watering the plants, sprinkler were used as
seen in Figure 1.
Mass Rearing of Healthy Cutworm
Mass rearing of healthy cutworms was done at the laboratory room. Rearing was
started with the collection of egg masses. Each egg mass were placed in separated
containers as seen in Figure 2 to avoid the crowding that force larvae to develop
cannibalistic behavior after they emerged. After emerging, they were feed on cabbage
leaves. The reared larvae served as the test insects and they were released in the test
cabbages direct in the field and for SINPV infection.
Figure 1. Watering of the cabbage plants after transplanting in the study
area
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
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Figure 2. Mass rearing of healthy cutworms on plastic containers in the
laboratory
Mass rearing of Spodoptera litura NPV
Cutworms infected with virus (SINPV) were collected. Infected cutworms are
characterized with bloated body with bad smell. Water was mixed with the collected
SINPV, macerated and served as the inoculums. Leaves of cabbages dipped on the
SINPV inoculums were offered to 2nd instar cutworm larvae. The larvae that were
infected became the source of SINPV for the research.
Procedures for the Testing of the Treatments
The effects of the treatments were tested on healthy cutworm larvae released on
cabbage plants in the open field but enclosed with nets. Plants were enclosed with nets to
prevent larval escape. The nets are cube shaped with the dimension of 1.0 X 1.0 X 1.0
meters as seen in Figure 3. Thirty early second instar healthy cutworm larvae were
released in each of the net cages. The treatments were laid out using the randomized
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
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complete block design (RCB). The treatments were replicated three times. The SINPV
treatments were applied through spray. Hand sprayer was used and the knap sack sprayer
for the treatment of Selecron. The rates of treatments used were as follows:
T1= 5 SINPV larvae/16 li water
T2= 10 SINPV larvae/16 li water
T3= 15 SINPV larvae/16 li water
T4= 20 SINPV larvae/6 li water
T5= 30 ml Selecron/16 li water
T6= Untreated
The data gathered were the number of dead cutworm larvae. The dead cutworms
were counted during the date of gathering after spraying. The degree of cutworm damage
was likewise determined by using the FPA rating scale index. The details of the scale
index are as follows: 1- sound or no damage, 3- slightly damaged, 5- moderately
damaged, 7- severely damaged and 9- heavily damaged. The percent marketable yield
was likewise recorded.
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
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Figure 3. The treatments lay-out using a net designed in cube shapes.
Inside the net cages were the treated cabbages and cutworms
Toxicity of SINPV on Diadegma
Rearing of Diadegma
A potted cabbage plants which are six weeks old were placed inside a parasite
adult nylon net cage with a wooden board floor. The larvae of DBM were allowed to feed
on the cabbage and emerge inside the cage until they become second instars. This stage
of larvae was used in rearing with larval parasites by placing Diadegma pupae inside the
cage allowing parasite adults to emerge. As a food source of newly emerge parasite
adults, a plastic sheet that was sprayed with honey was hanged and sprayed with honey
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
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solution daily. The door opening was covered with black cloth to avoid the escape of the
parasite adults. After these processes, the old potted cabbage was replaced with new ones
containing a numerous number of DBM that were second instars larvae. The exposed soil
was covered with aluminum foil and cabbage leaves were placed on the cage surrounding
the clay pot. This is to trap the DBM larvae descending from the plant when parasites try
to oviposit. The DBM larvae were allowed to oviposit by the parasites within 24 hours.
The cabbage plant with parasitized larvae were removed from the cage and all the leaves
were carefully stripped, making sure that larvae do not fall off. Two to three of the leaves
containing a numerous number of larvae were placed in a fresh 6 week old potted
cabbage plant in a similar but parasite-free cage. At this time, all DBM larvae that have
fallen from the leaves to the floor in the previous cage were transferred in the fresh
cabbage plant. When the food supply from the old excise leaves was exhausted, the
larvae migrated to the fresh leaves of the new plants.
The biomass of the 6-week-old plant provides enough food for larvae until
pupation in 15 days. The pupae were carefully collected and stored at 8 to 10 °C. The
pupae were stored at this temperature for 15 to 30 days without significant loss of
viability.
Procedures for Testing
Ten
Diadegma pupae were placed inside the container in each treatment. Each of
the containers was covered with net to minimize the escape of the adult Diadegma after
they emerged. After emerging, SINPV were sprayed through the net cover likewise on
the bottom surface of the top cover of the container before it was placed to make sure
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
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inside of the container were contaminated (figure 4). SINPV was observed if it has an
effect to the parasitoid insects. Adult Diadegma were also tested in a container that was
contaminated with chemical insecticide. The study was conducted using the completely
randomized designed (CRD). Untreated adult Diadegma was included as the basis for
comparison.
The data gathered were the number of dead adult Diadegma at 24, 48, and 72
hours after exposure from the treatment.
a
b
c
Figure 4. Treated adult of Diadegma with: a) 20 SINPV/16 li
water; b) 30 ml Seleron/16 li water; c)Untreated
RESULTS AND DISCUSSION
Mortality Action of the Treatments
It is presented in the data Table 1 the mortality of cutworm larvae 3 and 6 days
after the first treatment. It is clearly presented the far lower mortality in all the treatments
of SINPV 3 days after treatment. The highest mortality was 11.11% which was recorded
from the SINPV rate of 15 larvae/16 li water and 8.89% from the SINPV rate of 20
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
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larvae/16 li water. The mortality decreases as the SINPV rates were reduced. The
mortality of the standard treatment of Selecron was equivalent to 63.33% far higher than
the SINPV treatments. This result is a clear indication that Selecron has quick mortality
action against common cutworm which was absent from the treatments of SINPV.
Table 1. Mortality (%) of cutworm larvae 3 and 6 days after treatment of SINPV
TREATMENT
FIRST SPRAY
(Rates)
3 DAT
6 DAT
5 SINPV/16 li H2O 7.78bc 24.45c
10 SINPV/16 li H2O 7.78bc 26.67c
15 SINPV/16 li H2O 11.11b 57.78b
20 SINPV/16 li H2O 8.89bc 64.44ab
30 ml Selecron/16 li H2O
63.33a 67.78a
Untreated H2O 0.00c 0.00d
Means in a column with the same letter are not significantly different at 5% level
of significance by DMRT
*DAT- days after treatment
Effects of the SINPV Treatments
The mortality of cutworm larvae from the first until the third spray is presented in
Table 2.
Mortality of cutworm larvae during the first spray. It is clearly presented in the
data Table 2 the very low mortality of cutworms in all the SINPV treatments at the rates
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
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of 5, 10, 15 and 20 larvae/16 li water. The highest so far for the 3 days assessment after
spray was 11.11 and 8.89% which was observed from the 15 and 20 SINPV larvae/16 li
water. The mortality decreased as the rate was reduced to 5 and 10 SINPV larvae/16 li
water equivalent to 7.78 and 7.78%, respectively. While there was no mortality from the
untreated, the mortality was 63.33% from the standard treatment of Selecron.
Six days after first spray, the mortality of cutworm generally increased in all the
SINPV treatments. The highest which was noted from the highest rate of 20 SINPV
larvae/16 li water was 64.44% followed by 57.78% from the 15 SINPV larvae/16 li
water. The mortality from the two lower rates at 10 and 5 SINPV larvae were 26.67% and
24.45% respectively. The mortality from the standard treatment of Selecron was 67.78%.
Mortality of cutworm larvae during the second spray. The mortality of cutworm
larvae further increased in all the treatments of SINPV and the standard treatment of
Selecron. At 3 days after spray, the mortality was 68.89% from the highest rate at 20
SINPV larvae/16 li water, and 65.55% for the 15 SINPV larvae/16 li water. The mortality
from the two lower rates at 10 and 5 SINPV larvae/16 li water was 35.56% and 28.89%
respectively while a mortality of 73.33% was recorded from the treatment of Selecron.
Table 2. Mortality (%) of cutworm larvae during the first, second and third treatment
application
TREATMENT
1st SPRAY
2nd SPRAY
3rd SPRAY
(Rates)
3 DAT 6 DAT 3 DAT 6 DAT 3 DAT 6 DAT
5 SINPV/16
7.78bc 24.45c 28.89d 28.89d 28.89d 28.89c
li H2O
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
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10 SINPV/16
7.78bc 26.67c 35.56c 36.67c 36.67c 36.67c
li H2O
15 SINPV/16
11.11b 57.78b 65.55b 66.67b 67.78b 67.78b
li H2O
20 SINPV/16
8.89bc 64.44ab 68.89ab 68.89ab 68.89b 71.11ab
li H2O
30 ml Selecron/16
63.33a 67.78a 73.33a 75.56a 76.67a 76.67a
li H2O
Untreated 0.00c 0.00d 0.00e 0.00e 0.00e 0.00d
Means in a column with the same letter are not significantly different at 5% level
of significance by DMRT
*DAT- days after treatment
Six days after second spray, the mortality of cutworm larvae from the highest rate
of 20 SINPV larvae/16 li water was 68.89% and 66.67% from the rate of 15 SINPV
larvae/16 li water. The mortality for the rates of 10 SINPV larvae/16 li water was 36.67%
while in the lowest rate at 5 SINPV larvae/16 li water was 28.89%. The mortality from
the treatment of Selecron was 75.56%.
Mortality of cutworm larvae during the third spray. The mortality of cutworm
larvae (Figure 5) from the highest rate of 20 SINPV larvae/16 li water 3 days after the
third spray was 68.89% and a mortality of 67.78 % from the rate of 15 SINPV larvae/16
li water. The mortality from the two lower rates at 10 and 5 SINPV larvae/16 li water
were 36.67 and 28.89% respectively and 76.67% from standard treatment of Selecron.
Six days after the last treatment and last data gatherings, the trend of results were
likewise more or less similar. The mortality from highest rate of SINPV at 20 larvae/16 li
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
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water was 71.11% while the mortality from the three lower rates at 15, 10 and 5 SINPV
larvae/16 li water were 67.78, 36.67, and 28.89% respectively. The mortality from the
standard treatment of Selecron was 76.67%.
Figure 5. Appearance of infected cutworms caused by SINPV treatments
Degree of Cutworm Damage
The assessed damage in cabbage caused by cutworm is presented in Table 3. As
early as the first treatment application, all the treatments of SINPV, the standard
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
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treatment of Selecron and the untreated were rated slightly damaged. On the other hand,
as time went by and the application of SINPV and the standard Selecron progresses,
damage differences were noted. The highest rates of SINPV at 20 and 15 larvae/16 li
water were slightly damaged comparable with the treatment of Selecron. The lowest
dosage rate of SINPV at 5 larvae/16 li water was moderately damaged while the
untreated was severely damaged.
Table 3. Degree of damage caused by cutworm as affected by the treatments
TREATMENT
3 DAT
10 DAT
20 DAT
(Rates)
5 SINPV/16 li H2O 3.00a 3.00b 5.00b
10 SINPV/16 li H2O 3.00a 3.00b 4.33bc
15 SINPV/16 li H2O 3.00a 3.00b 3.67cd
20 SINPV/16 li H2O 3.00a 3.00b 3.00d
30 ml Selecron/16 li H2O 3.00a 3.00b 3.00d
Untreated 3.67a 5.67a 9.00a
Means in a column with the same letter are not significantly different at 5% level
of significance by DMRT
* The first treatment was applied 30 days after transplanting
* DAT- days after treatments
Marketable Yield (%)
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
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The percent marketable yield is presented in Table 4. Highest marketable yield
equivalent to 91.67% was recorded from the standard treatment of Selecron. Marketable
yields equivalent to 89.67 and 83.00% were recorded from the treatments of 20 and 15
SINPV larvae/16 li water, respectively. Percent marketable yields were numerically
lower in comparison with the treatment of Selecron but statistically, they were
insignificant. The percent marketable yield from the 10 SINPV larvae/16 li water was
62.00% and 53% from 5 SINPV larvae/16 li water.
Due to severe damaged caused by cutworm, marketable yield was not harvested
from the untreated.
Table 4. Marketable yield (%) as affected by the treatments of SINPV
TREATMENT
MEAN
(Rates)
5 SINPV/16 li H2O
53. 67b
10 SINPV/16 li H2O
62.00b
15 SINPV/16 li H2O
83.00a
20 SINPV/16 li H2O
89.67a
30 ml Selecron/16 li H2O
91.67a
Untreated
0.00c
Means with the same letter are not significantly different at 5% level of
significance by DMRT
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
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Mortality (%) of Adult Diadegma
The mortality of adult Diadegma is presented in Table 5. It is clearly presented in
the data table the absence of dead adult Diadegma from the treatment of SINPV similar
with the untreated. The results imply that SINPV does not harm adult Diadegma when
applied in cabbage for the control of cutworm. On the other hand, the standard Selecron
is extremely toxic to adult Diadegma brought about by the mortality of the parasitoid to
as high as 100%. The results likewise imply that the use of the said insecticide in the field
for the control of DBM may endanger the parasitoid Diadegma.
Table 5. Mortality (%) of adult Diadegma after exposure from the treatments of SINPV
and Selecron
TREATMENT
RATE
24 HAT
48 HAT
72 HAT
SINPV
20 larvae/16 li H2O 0.00b 0.00b 0.00b
Selecron 30
ml/16
li
H2O 93.
33a 100.00a 100.00a
Untreated ___
0.00b 0.00b 0.00b
* HAT- hours after treatment
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
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SUMMARY, CONCLUSIONS AND RECOMMENDATION
Summary
The study was conducted at Buyacaoan, Buguias, Benguet from July to
November 2010, a place in Buguias where cabbage is widely planted and where the
insect cutworm is one of the most injurious pest’s insect. This study was conducted
purposely to determine the number of Spodoptera litura Nucleopolyhedrovirus (SINPV)
larvae effective against common cutworm larvae, and to determine should SINPV has
harm effect on adult Diadegma, a parasitoid of diamondback moth.
Thirty early second instar healthy cutworm larvae were released on the cabbage
plants enclosed with nets and sprayed with the treatments which are as follows; 5, 10, 15,
20 SINPV larvae/ 16 li water. Selecron 50 EC at the rate of 30 ml/16 li water was the
standard insecticide. Untreated cutworm larvae were included as the basis for
comparison.
The mortality of cutworm larvae from SINPV treatments was 71.11% at 20
larvae/16 li water, followed by 67.78% on the treatment of 15 SINPV larvae/16 li water
and 36.67% on the treatment of 10 SINPV larvae/16 li water. The treatment of 5 SINPV
larvae/16 li water has the lowest level of mortality equivalent to 28.89% while a mortality
of 76.67 on the standard treatment of Selecron the mortality recorded was 76.67%.
The two highest rates of SINPV at 20 and 15 larvae/16 li water were slightly
damaged comparable with the treatment of Selecron. The two lower dosage rate of
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
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SINPV at 10 and 5 larvae/16 li water was moderately damaged while the untreated was
severely damaged.
The two highest rates of SINPV treatments from 15 to 20 NPV larvae/16 li water
had the highest percentage of marketable yield equivalent to 83.00 and 89.67%
comparable with the standard treatment of Selecron which was 91.67%. The marketable
yield decreased significantly as the rates of SINPV treatments was reduced to 5 and 10
SINPV larvae/16 li water. Marketable yield was not harvested from the untreated.
Mortality of adult Diadegma was not noted in all the SINPV treatments similar
with the untreated. On the other hand, mortality of 100% was recorded from the standard
treatment of Selecron.
Conclusions and Recommendation
It is concluded that microbial insecticide like SINPV has the efficacy against
cutworm of cabbage comparable to Selecron 50 EC. The SINPV rate of 20 and 15
larvae/16 li water are effective against cutworm. SINPV is not toxic to adult Diadegma.
SINPV is recommended for the control of cutworm in cabbage.
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
22
LITERATURE CITED
AGSAOAY, M. 1998. Management of the cutworm, Spodoptera litura Fabr. On peanut
(Arachis hypogea L.) using Bacillus thuringiensis Berliner and
nuclearpolyhedrosis virus. Ph.D. In the Philippine Entomologist Journal. Dept.
of Entom., UPLB, Laguna. 13(2): 167.
BAKER, C. R. B. and G. W. MILLER. 1974. Some effects of temperature and larval
food on the development of Spodoptera littoralis. Bulletin of Entomological
Research.
63:469-511.
CARDONA E. V., C. S. LIGAT, M. P. SUBANG. 2007. Life History of Common
Cutworm,
Spodoptera litura Fabricius (Noctuidae: Lepidoptera) in Benguet. BSU
Research Journal. No. 56. P.73.
GABRIEL, B. P. 1997. Insects and mites injurious to Philippines crop plants. National
Crop Protection Center, UPLB, College, Los Banos Laguna. NAFC-DA. 171p.
IGNOFFO, C. M. and A. M. HEIMPEL. 1965. The nuclearpolyhedrosis virus of
Heliotics zea (Boddie) and Heliotics virescens (Fabricius). J. Invertebr. Pathol.
7:329-340.
JAQUES, R. P. 1967. The persistence of nuclearpolyhedrosis virus in the habitat of hosts
insect
Trihoplusia ni II. Can. Ent. 99:820-829.
LAVINA B. A., L. E. PADUA, F. Q. WU, N. SHIRATA, M. IKEDA and M.
KOBAYASHI. 2000. Biological characterization of a nuclearpolyhedrosis virus
of
S. litura (Lepidoptera: Noctuidae) Isolated from the Philippines. Biol. Cont.
20:39-47.
MIYAHARA, Y., T. WAKIKADO and TANAKA. 1971. Seasonal changes in the
number and size of the egg-masses of prodenia litura. Japanese Journal of
Applied Entomology and Zoology. 8:205-214
NAVASERO, M. N. and M. M. NAVASERO. 2002. Potential of Farm-Level Production
and Utilization of Spodoptera litura Nucleopolyhedrosis Virus. Philipp. Ent.
17(2):
179-
182.
PADUA, L. E., V. GAPUD, E. C. MARTIN, C. PILE, B. A. SANTIAGO, N. S.
TALEKAR, G. F. RECTA, E. G. RAJOTTE and A. C. LAPUS.1999. Field
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
23
efficacy of nuclear polyhedrosis virus (NVP) and Bacillus thuringiensis (BT) for
Spodoptera control in Yellow Granex onions. Philippine Ent. 13(2): 159-168.
PODGWAITE, J. D., K. S. SHIELDS, R. T. ZERILLO and R. B. BUEN. 1979.
Environmental persistence of the nuclearpolyhedrosis virus of the gypsy moth,
Lymantria dispar. Environmental Entomology. 8:528-536.
RAO, G. V. R., J. A. WIGTMAN and D. V. R. RAO. 1989. Threshold temperatures and
thermal requirement for the development of Spodoptera litura. Environmental
Entomology.
18:548-551
SCHMUTTER, H. 1969. Pest of crops in Northeast and Central Africa. Germany: Gustav
Fischer Verlag: Pp. 186-188.
VAN HUIS, A. 1989. Integrated management of insect pests in tropical crops. Vol. I. G:
50-110.
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
24
APPENDICES
Appendix Table 1. Mortality (%) of cutworm larvae 3 days after the first treatment
application
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
5 SINPV/16 li
6.67 6.67 10.00 23.34 7.78
H2O
2
10 SINPV/16 li
10.00 10.00 3.33 23.33 7.78
H2O
3
15 SINPV/16 li
16.67 10.00 6.67 33.34 11.11
H2O
4
20 SINPV/16 li
13.33 3.33 10.00 26.66 8.89
H2O
5 30
ml
Selecron/16
56.67 63.33 70.00 190 63.33
li H2O
6
Untreated 0.00
0.00
0.00
0.00
0.00
ANALYSIS OF VARIANCE
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
VARIANCE
OF
SQUARES
SQUARES
FREEDOM
Model
7
8122.827217 1160.403888
52.52**
< .0001
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
25
Block
2
8.658033 4.329017
0.20
0.8252
Treatment 5
8114.169183 1622.833837
73.45
<
.0001
Error
10
220.956833 22.095683
CORRECTED
17 8343.784050
TOTAL
**Highly Significant
Coefficient of variation = 28.52020%
Appendix Table 2. Mortality (%) of cutworm larvae 6 days after the first treatment
application
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
5 SINPV/16 li
30.00 16.67 26.67 73.34 24.45
H2O
2
10 SINPV/16 li
30.00 20.00 30.00 80.00 26.67
H2O
3
15 SINPV/16 li
63.33 50.00 60.00 173.33 57.78
H2O
4
20 SINPV/16 li
73.33 56.67 63.33 193.33 64.44
H2O
5 30
ml
Selecron/16
63.33 70.00 70.00 203.33 67.78
li H2O
6
Untreated 0.00
0.00
0.00
0.00
0.00
ANALYSIS OF VARIANCE
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
VARIANCE
OF
SQUARES
SQUARES
FREEDOM
Model 7
11314.63462 1616.37637
70.78**
< .0001
Block
2
201.10990 100.55495
4.40
0.0425
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
26
Treatment 5
11113.52472 2222.70494
97.33
< .0001
Error
10
228.37163 22.83716
CORRECTED
17 11543.00625
TOTAL
**Highly Significant
Coefficient of variation = 11.89206%
Appendix Table 3. Mortality (%) of cutworm larvae 3 days after the second treatment
application
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
5 SINPV/16 li
30.00 26.67 30.00 86.67 28.89
H2O
2
10 SINPV/16 li
40.00 30.00 36.67 106.67 35.56
H2O
3
15 SINPV/16 li
70.00 63.33 63.33 196.66 65.55
H2O
4
20 SINPV/16 li
76.67 66.67 63.33 206.67 68.89
H2O
5 30
ml
Selecron/16
73.33 70.00 76.67 220.00 73.33
li H2O
6
Untreated 0.00
0.00
0.00
0.00
0.00
ANALYSIS OF VARIANCE
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
VARIANCE
OF
SQUARES
SQUARES
FREEDOM
Model 7
12600.31237 1800.14462 158.29**
< .0001
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
27
Block
2
93.80988 46.90494
4.12
0.0494
Treatment 5
12506.50249 2501.30050 219.96 <
.0001
Error
10
113.71612 11.37161
CORRECTED
17 12714.02849
TOTAL
**Highly Significant
Coefficient of variation = 7.432534%
Appendix Table 4. Mortality (%) of cutworm larvae 6 days after the second treatment
application
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
5 SINPV/16 li
30.00 26.67 30.00 86.67 28.89
H2O
2
10 SINPV/16 li
40.00 30.00 40.00 110.00 36.67
H2O
3
15 SINPV/16 li
70.00 66.67 63.33 200.00 66.67
H2O
4
20 SINPV/16 li
76.67 66.67 63.33 206.67 68.89
H2O
5 30
ml
Selecron/16
73.33 76.67 76.67 226.67 75.56
li H2O
6
Untreated 0.00
0.00
0.00
0.00
0.00
ANALYSIS OF VARIANCE
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
VARIANCE
OF
SQUARES
SQUARES
FREEDOM
Model
7
13009.45188 1858.49313 122.27**
< .0001
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
28
Block
2
48.10743 24.05372
1.58
0.2529
Treatment 5
12961.34445 2592.26889 170.54 <
.0001
Error
10
152.00377 15.20038
CORRECTED
17 13161.45565
TOTAL
**Highly Significant
Coefficient of variation = 8.455053%
Appendix Table 5. Mortality (%) of cutworm larvae 3 days after the third treatment
application
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
5 SINPV/16 li
30.00 26.67 30.00 86.67 28.89
H2O
2
10 SINPV/16 li
40.00 30.00 40.00 110.00 36.67
H2O
3
15 SINPV/16 li
70.00 66.67 66.67 203.34 67.78
H2O
4
20 SINPV/16 li
76.67 66.67 63.33 206.67 68.89
H2O
5 30
ml
Selecron/16
73.33 76.67 80.00 230.00 76.67
li H2O
6
Untreated 0.00
0.00
0.00
0.00
0.00
ANALYSIS OF VARIANCE
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
VARIANCE
OF
SQUARES
SQUARES
FREEDOM
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
29
Model 7
13345.32349 1906.47478 123.44**
< .0001
Block
2
45.62471 22.81236
1.48
0.2741
Treatment 5
13299.69878 2659.93976 172.23 <
.0001
Error
10
154.44202 15.44420
CORRECTED
17 13499.76551
TOTAL
**Highly Significant
Coefficient of variation = 8.454654%
Appendix Table 6. Mortality (%) of cutworm larvae 6 days after the third treatment
application
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
5 SINPV/16 li
30.00 26.67 30.00 86.67 28.89
H2O
2
10 SINPV/16 li
40.00 30.00 40.00 110.00 36.67
H2O
3
15 SINPV/16 li
70.00 66.67 66.67 203.34 67.78
H2O
4
20 SINPV/16 li
80.00 70.00 63.33 213.33 71.11
H2O
5 30
ml
Selecron/16
73.33 76.67 80.00 230.00 76.67
li H2O
6
Untreated 0.00
0.00
0.00
0.00
0.00
ANALYSIS OF VARIANCE
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
30
VARIANCE OF SQUARES SQUARES
FREEDOM
Model 7
13656.11979 1950.87426
98.10**
< .0001
Block
2
45.62841
22.81421
1.15
0.3560
Treatment 5
13610.49138 2722.09828 136.88 <
.0001
Error
10
198.86052 19.88605
CORRECTED
17 13854.98031
TOTAL
**Highly Significant
Coefficient of variation = 9.517965%
Appendix Table 7. Degree of damage caused by cutworm larvae 3 days after the
treatment
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
5 SINPV/16 li
3 3 3 9 3.00
H2O
2
10 SINPV/16 li
3 3 3 9 3.00
H2O
3
15 SINPV/16 li
3 3 3 9 3.00
H2O
4
20 SINPV/16 li
3 3 3 9 3.00
H2O
5 30
ml
Selecron/16
3 3 3 9 3.00
li H2O
6
Untreated 3 3 5 11
3.67
ANALYSIS OF VARIANCE
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
31
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
VARIANCE
OF
SQUARES
SQUARES
FREEDOM
Model 7
1.55555556
0.22222222
1.00ns
0.4834
Block 2
0.44444444
0.22222222
1.00
0.4019
Treatment 5
1.11111111
0.22222222 1.00 0.4651
Error 10
2.22222222
0.22222222
CORRECTED
17 3.77777778
TOTAL
ns Not Significant
Coefficient of variation = 15.15229%
Appendix Table 8. Degree of damage caused by cutworm larvae 10 days after the
treatments
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
5 SINPV/16 li
3 3 3 9 3.00
H2O
2
10 SINPV/16 li
3 3 3 9 3.00
H2O
3
15 SINPV/16 li
3 3 3 9 3.00
H2O
4
20 SINPV/16 li
3 3 3 9 3.00
H2O
5 30
ml
Selecron/16
3 3 3 9 3.00
li H2O
6
Untreated 5 5 7 17
5.67
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
32
ANALYSIS OF VARIANCE
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
VARIANCE
OF
SQUARES
SQUARES
FREEDOM
Model 7
18.22222222 2.60317460
11.71*
0.0004
Block
2
0.44444444 0.22222222
1.00
0.4019
Treatment 5
17.77777778 3.55555556 16.00 0.0002
Error
10
2.22222222 0.22222222
CORRECTED
17 20.44444444
TOTAL
*Significant Coefficient of variation = 13.68594%
Appendix Table 9. Degree of damage caused by cutworm larvae 20 days after the
treatments
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
5 SINPV/16 li
5 5 5 15 5.00
H2O
2
10 SINPV/16 li
5 5 3 13 4.33
H2O
3
15 SINPV/16 li
3 5 3 11 3.67
H2O
4
20 SINPV/16 li
3 3 3 9 3.00
H2O
5 30
ml
Selecron/16
3 3 3 9 3.00
li H2O
6
Untreated 9 9 9 27
9.00
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
33
ANALYSIS OF VARIANCE
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
VARIANCE
OF
SQUARES
SQUARES
FREEDOM
Model 7
78.00000000 11.14285714
27.86**
< .0001
Block
2
1.33333333 0.66666667
1.67
0.2373
Treatment 5
76.66666667 15.33333333
38.33 <
.0001
Error
10
4.00000000 0.40000000
CORRECTED
17 82.0000000
TOTAL
**Highly Significant
Coefficient of variation = 13.55262%
Appendix Table 10. Marketable yield (%) as affected by the treatments of SINPV
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
5 SINPV/16 li
45 56 60 161 53.67
H2O
2
10 SINPV/16 li
53 60 73 186 62.00
H2O
3
15 SINPV/16 li
84 85 80 249 83.00
H2O
4
20 SINPV/16 li
90 87 92 269 89.67
H2O
5 30
ml
Selecron/16
90 95 90 275 91.67
li H2O
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
34
6
Untreated 0.00
0.00
0.00
0.00
0.00
ANALYSIS OF VARIANCE
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
VARIANCE
OF
SQUARES
SQUARES
FREEDOM
Model 7
18061.00000 2580.14286
93.15**
< .0001
Block
2
93.00000 46.50000
1.68
0.2352
Treatment 5
17968.00000 3593.60000 129.73 <
.0001
Error
10
277.00000 27.70000
CORRECTED
17 18338.00000
TOTAL
**Highly Significant
Coefficient of variation = 8.310125%
Appendix Table 11. Mortality (%) of adult Diadegma after 24 hours of exposure from the
treatments of SINPV and Selecron
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
20 SINPV/16 li
0.00 0.00 0.00 0.00 0.00
H2O
2 30
ml
Selecron/16
90.00 100.00 90.00 280 93.33
li H2O
3
Untreated 0.00
0.00
0.00
0.00
0.00
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
35
ANALYSIS OF VARIANCE
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
VARIANCE
OF
SQUARES
SQUARES
FREEDOM
Model 2
17422.22222 8711.11111
784.00*
< .0001
Treatment 2
17422.22222 8711.11111 784.00 <
.0001
Error
6
66.66667 11.11111
CORRECTED
8 17488.88889
TOTAL
*Significant Coefficient of variation = 10.71429%
Appendix Table 12. Mortality (%) of adult Diadegma after 48 hours of exposure from the
treatments of SINPV and Selecron
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
20 SINPV/16 li
0.00 0.00 0.00 0.00 0.00
H2O
2 30
ml
Selecron/16
100.00 100.00 100.00 300.00 93.33
li H2O
3
Untreated 0.00
0.00
0.00
0.00
0.00
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
36
ANALYSIS OF VARIANCE
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
VARIANCE
OF
SQUARES
SQUARES
FREEDOM
Model 2
20000.00000 10000.00000
Infty*
< .0001
Treatment 2
20000.00000 10000.00000
Infty <
.0001
Error
6
0.00000 0.00000
CORRECTED
8 20000.00000
TOTAL
*Significant
Coefficient of variation = 0
Appendix Table 13. Mortality (%) of adult Diadegma after 72 hours of exposure from the
treatments of SINPV and Selecron
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
20 SINPV/16 li
0.00 0.00 0.00 0.00 0.00
H2O
2 30
ml
Selecron/16
100.00 100.00 100.00 300.00 93.33
li H2O
3
Untreated 0.00
0.00
0.00
0.00
0.00
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
37
ANALYSIS OF VARIANCE
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
VARIANCE
OF
SQUARES
SQUARES
FREEDOM
Model 2
20000.00000 10000.00000
Infty*
< .0001
Treatment 2
20000.00000 10000.00000
Infty <
.0001
Error
6
0.00000 0.00000
CORRECTED
8 20000.00000
TOTAL
*Significant
Coefficient of variation = 0
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
IGUALDO, JIRLDANMYR DIONISIO D. APRIL 2011. Field Efficacy
Evaluation of Nucleopolyhedrovirus Against Common Cutworm (Spodoptera litura
Fabr.) on Head Cabbage in Buguias, Benguet. Benguet State University, La Trinidad,
Benguet.
Adviser: Eulogio V. Cardona, Jr., PhD.
ABSTRACT
The study was conducted at Buyacaoan, Buguias, Benguet from July to
November 2010 to determine the number of Spodoptera litura Nucleopolyhedrovirus
(SINPV) larvae effective against healthy common cutworm larvae, and to determine
should SINPV has harm effect on adult Diadegma, a natural enemy of diamondback
moth.
Thirty early second instar healthy cutworm larvae were released on the cabbage
plants enclosed with nets and sprayed with the treatments which are as follows; 5, 10, 15,
20 SINPV larvae/ 16 li water. Selecron 50 EC at the rate of 3 TBSP/16 li water was the
standard insecticide. As basis for comparison, untreated cutworm larvae were included.
The mortality of cutworm larvae on the standard treatment of Selecron was the
highest equivalent to 76.67%, 71.11% on the SINPV treatment of 20 larvae/16 li water,
67.78% on the treatment of 15 SINPV larvae/16 li water and 36.67% on the treatment of
10 SINPV larvae/16 li water. The treatment of 5 SINPV larvae/16 li water has the lowest
level of mortality equivalent to 28.89%.
The treatments sprayed with the rate of 20 and 15 SINPV larvae/16 li water were
slightly damaged similar with the standard treatment of Selecron. The lower rates of
SINPV applied were moderately damaged.
The two highest rates of SINPV treatments at 15 to 20 larvae/16 li water had the
highest percentage of marketable yield equivalent to 83.00 and 89.67% comparable with
the standard treatment of Selecron which was 91.67%. The marketable yield decreased
significantly as the rates was reduced to 5 and 10 SINPV larvae/16 li water.
Mortality of adult Diadegma was not noted in all the SINPV treatments similar
with the untreated but mortality of 100% was recorded from the standard treatment of
Selecron.
It is concluded that SINPV at the rate of 20 and 15 larvae/16 li water has the
efficacy against cutworm of cabbage comparable to Selecron 50 EC. SINPV is not toxic
to adult Diadegma. SINPV is recommended for the control of cutworm in cabbage.
ii
TABLE OF CONTENTS
Page
Bibliography……………………………………………………………………….
i
Abstract …………………………………………………………………………...
i
Table of Contents ………………………………………………………………… iii
INTRODUCTION ………………………………………………………………...
1
REVIEW OF LITERATURE ……………………………………………..............
3
MATERIALS AND METHODS …………………………………………………
6
Toxicity of SNPV Against
Cutworm Larvae ………………………………………………………….
6
Toxicity of SINPV on Diadegma ………………………………………… 10
RESULTS AND DISCUSSION ………………………………………………….
12
Mortality Action of the Treatments ………………………………………
12
Effects of the SINPV Treatments ………………………………………...
13
Degree of Cutworm Damage ……………………………………………..
16
Marketable Yield (%) …………………………………………………….
17
Mortality (%) on Adult Diadegma ………………………………………. 18
SUMMARY, CONCLUSION AND RECOMMENDATION …………………..
19
LITERATURE CITED …………………………………………………………..
21
APPENDICES ………………………………………………………………….
23
1
INTRODUCTION
Common cutworm (Spodoptera litura Fabr.) is classified to belong to the order
Lepidoptera; Family Noctuidae. It is one of the primary problems of the majority of
vegetable growers. Cutworms have a very powerful mandible and this is use in damaging
cabbage by cutting the stem and chewing the leaves. In the Philippines, the insect infests
28 agricultural crops. Aside for cabbage and related crucifers, other crops infested by the
insect are tobacco in Ilocos region, onion in Nueva Ecija, peanut in Isabela, and beans
and rice in many parts of the country (Gabriel, 1997).
In Benguet Province like in other parts of the country, cutworm is a serious
problem. It is a problem in most semi-temperate leafy vegetables particularly cabbage.
Chemical insecticide is the usual practice of controlling cutworms. But with the many
disadvantages associated with its use, an environment-friendly method of controlling
cutworms like Spodoptera litura Nucleopolyhedrovirus (SINPV) is one of the possible
alternatives.
Microbial control or the use of viruses has been identified as both viable and
promising alternative for the chemical control of cutworms. Local strains of the
nucleopolyhedrovirus or cutworm have already been isolated and laboratory tested
(Padua et al., 1999).
One of the microbial pathogens with insecticidal activity against cutworm is
Nucleopolyhedrovirus (NPV). Studies for the efficacy of NPV against cutworm are many
especially in the lowland areas. For example, in the study of Agsaoay in 1998, NPV was
proven effective against cutworm of peanut and in asparagus as reported by Padua
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(1999). It was likewise mentioned by Navasero and Navasero (2002) that NPV was
effective against cutworm in egg plants. NPV are likewise cheap, environment friendly
and harmless to human. But in some places here in Benguet especially in Buguias, the
efficacy of SINPV was not yet tested.
The study aimed to determine the number of Spodoptera litura
Nucleopolyhedrovirus (SINPV) larvae effective against healthy common cutworm larvae,
and to determine should SINPV has harm effect on adult Diadegma, the natural enemy of
diamondback moth.
The study was conducted at Buyacaoan, Buguias, Benguet from July to
November 2010.
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REVIEW OF LITERATURE
Biology of Cutworm
Miyahara et al. (1971), Rao et al. (1989), Schmutter (1969), Baker and Miller
(1974) stated that female Spodoptera litura laid egg masses with around 1000-2000 eggs
per mass. The eggs are spherical, somewhat flattened, 0.6mm in diameter and covered
with hair like scales. Usually, it is pale orange, brown or white to dull or off-white in
color. They hatch in about 4 days in warm conditions or 11-12 days in winter times.
During the dry seasons of 1995, IDM-CRSP gathered data on the major and minor
insect pests and their natural enemies on rice vegetable system. Results of these efforts
have led to the identification of S. litura (Fabr). As one of the pest of onion, common
cutworm is one among the most economically important insect pests in the country. The
newly emerged larvae gregariously feed on the soft leaf tissues. The damage done by this
pest is exhibited by large feeding holes on the blades of mature and young leaves (Padua
et al., 1999).
Nature of Cutworm Damage
Cabbage is one of the vegetables attacked by S. litura. The insect damage the
stems, consuming the whole seedling, chewing the leaves of the plants in the open fields
causing irregular holes and boring the developing heads with lace of larval excrements. If
not controlled, the insect can reduce yield to as high as 50% to 100% (Cardona et al.,
2007).
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Microbial Control of Cutworm
Van Huis (1989) reported a number of entomopathogenic microorganisms (e.g.,
bacteria, fungi, protozoa, nematodes, and viruses) which are potential components in
insect pest management like the NVP. Studies revealed that these entomogenous
microbial agents can be potent instruments in reducing insect pest populations below
economic threshold. Insect viruses and bacteria in particular have appreciably shown
evidences as pest suppressive agents that could complement other control measures.
Pathogenicity and Toxicity test for SINPV
Ignoffo and Hiempel (1965) exposed guinea pigs and white mice to NPV of
Heliothiz zea (Boddie) and H. virescens (Fabricius) to test the pathogenicity and toxicity
of NPV. The virus was administered in the form of poly-inclusion bodies, free virus rods
or polyhedral protein through inhalation and feeding. Intravenous, intradermal,
intraperitoneal and intercerebral injections of the virus were also done. Except for one
pneumonia-caused death, all the test animals showed normal weight gains. Also, no
abnormalities were observed.
Podgwaite et al. (1979) estimated infectious Lymantria dispar NPV naturally
occurring in leaf, bark, litter, and soil. Concentrations of the virus were then compared
with the concentrations of the virus taken after NPV treatment of these plots. These
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comparisons revealed that NPV is a natural component of the host’s habitat and that
further NPV application did not cause an increase in NPV load.
Jaques (1967) evaluated the persistence of NPV in soil. Soil samples of 6.4 x
1010- treated plots contained 25% of the original infective virus after 5 years. A similar
rate of decline in viral activity was noted in soils exposed to artificial conditions.
Lavina et al. (2000) reported that S. litura NPV is a unique and distinct isolate;
further finger printing of the virus is currently being undertaken.
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MATERIALS AND METHODS
Toxicity of SINPV Against Cutworm Larvae
Site Selection
The study was conducted at Buyacaoan, Buguias, Benguet, a place in Buguias
where cabbage is widely planted and where the insect cutworm is one of the most
injurious pest’s insect. The research area were cleaned by the used of sickle and grab hoe.
Plot making and chicken dung application were done before the one month old seedlings
of the cabbage Scorpio variety were planted.
Preparation and Maintenance of Cabbage
Plants preparation was started by soaking the cabbage seeds for twenty four hours
before seeding on plots. After four weeks of care and maintenance of the seedlings, they
were transplanted in the study area. The application of the recommended rate of urea (46-
0-0) and complete (14-14-14) were done during the early vegetative stage to improve the
vigor of the plants and becomes more ideal for research purposes. Likewise, fungicide
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was applied to prevent buildup of diseases. In watering the plants, sprinkler were used as
seen in Figure 1.
Mass Rearing of Healthy Cutworm
Mass rearing of healthy cutworms was done at the laboratory room. Rearing was
started with the collection of egg masses. Each egg mass were placed in separated
containers as seen in Figure 2 to avoid the crowding that force larvae to develop
cannibalistic behavior after they emerged. After emerging, they were feed on cabbage
leaves. The reared larvae served as the test insects and they were released in the test
cabbages direct in the field and for SINPV infection.
Figure 1. Watering of the cabbage plants after transplanting in the study
area
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Figure 2. Mass rearing of healthy cutworms on plastic containers in the
laboratory
Mass rearing of Spodoptera litura NPV
Cutworms infected with virus (SINPV) were collected. Infected cutworms are
characterized with bloated body with bad smell. Water was mixed with the collected
SINPV, macerated and served as the inoculums. Leaves of cabbages dipped on the
SINPV inoculums were offered to 2nd instar cutworm larvae. The larvae that were
infected became the source of SINPV for the research.
Procedures for the Testing of the Treatments
The effects of the treatments were tested on healthy cutworm larvae released on
cabbage plants in the open field but enclosed with nets. Plants were enclosed with nets to
prevent larval escape. The nets are cube shaped with the dimension of 1.0 X 1.0 X 1.0
meters as seen in Figure 3. Thirty early second instar healthy cutworm larvae were
released in each of the net cages. The treatments were laid out using the randomized
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complete block design (RCB). The treatments were replicated three times. The SINPV
treatments were applied through spray. Hand sprayer was used and the knap sack sprayer
for the treatment of Selecron. The rates of treatments used were as follows:
T1= 5 SINPV larvae/16 li water
T2= 10 SINPV larvae/16 li water
T3= 15 SINPV larvae/16 li water
T4= 20 SINPV larvae/6 li water
T5= 30 ml Selecron/16 li water
T6= Untreated
The data gathered were the number of dead cutworm larvae. The dead cutworms
were counted during the date of gathering after spraying. The degree of cutworm damage
was likewise determined by using the FPA rating scale index. The details of the scale
index are as follows: 1- sound or no damage, 3- slightly damaged, 5- moderately
damaged, 7- severely damaged and 9- heavily damaged. The percent marketable yield
was likewise recorded.
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Figure 3. The treatments lay-out using a net designed in cube shapes.
Inside the net cages were the treated cabbages and cutworms
Toxicity of SINPV on Diadegma
Rearing of Diadegma
A potted cabbage plants which are six weeks old were placed inside a parasite
adult nylon net cage with a wooden board floor. The larvae of DBM were allowed to feed
on the cabbage and emerge inside the cage until they become second instars. This stage
of larvae was used in rearing with larval parasites by placing Diadegma pupae inside the
cage allowing parasite adults to emerge. As a food source of newly emerge parasite
adults, a plastic sheet that was sprayed with honey was hanged and sprayed with honey
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solution daily. The door opening was covered with black cloth to avoid the escape of the
parasite adults. After these processes, the old potted cabbage was replaced with new ones
containing a numerous number of DBM that were second instars larvae. The exposed soil
was covered with aluminum foil and cabbage leaves were placed on the cage surrounding
the clay pot. This is to trap the DBM larvae descending from the plant when parasites try
to oviposit. The DBM larvae were allowed to oviposit by the parasites within 24 hours.
The cabbage plant with parasitized larvae were removed from the cage and all the leaves
were carefully stripped, making sure that larvae do not fall off. Two to three of the leaves
containing a numerous number of larvae were placed in a fresh 6 week old potted
cabbage plant in a similar but parasite-free cage. At this time, all DBM larvae that have
fallen from the leaves to the floor in the previous cage were transferred in the fresh
cabbage plant. When the food supply from the old excise leaves was exhausted, the
larvae migrated to the fresh leaves of the new plants.
The biomass of the 6-week-old plant provides enough food for larvae until
pupation in 15 days. The pupae were carefully collected and stored at 8 to 10 °C. The
pupae were stored at this temperature for 15 to 30 days without significant loss of
viability.
Procedures for Testing
Ten
Diadegma pupae were placed inside the container in each treatment. Each of
the containers was covered with net to minimize the escape of the adult Diadegma after
they emerged. After emerging, SINPV were sprayed through the net cover likewise on
the bottom surface of the top cover of the container before it was placed to make sure
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inside of the container were contaminated (figure 4). SINPV was observed if it has an
effect to the parasitoid insects. Adult Diadegma were also tested in a container that was
contaminated with chemical insecticide. The study was conducted using the completely
randomized designed (CRD). Untreated adult Diadegma was included as the basis for
comparison.
The data gathered were the number of dead adult Diadegma at 24, 48, and 72
hours after exposure from the treatment.
a
b
c
Figure 4. Treated adult of Diadegma with: a) 20 SINPV/16 li
water; b) 30 ml Seleron/16 li water; c)Untreated
RESULTS AND DISCUSSION
Mortality Action of the Treatments
It is presented in the data Table 1 the mortality of cutworm larvae 3 and 6 days
after the first treatment. It is clearly presented the far lower mortality in all the treatments
of SINPV 3 days after treatment. The highest mortality was 11.11% which was recorded
from the SINPV rate of 15 larvae/16 li water and 8.89% from the SINPV rate of 20
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larvae/16 li water. The mortality decreases as the SINPV rates were reduced. The
mortality of the standard treatment of Selecron was equivalent to 63.33% far higher than
the SINPV treatments. This result is a clear indication that Selecron has quick mortality
action against common cutworm which was absent from the treatments of SINPV.
Table 1. Mortality (%) of cutworm larvae 3 and 6 days after treatment of SINPV
TREATMENT
FIRST SPRAY
(Rates)
3 DAT
6 DAT
5 SINPV/16 li H2O 7.78bc 24.45c
10 SINPV/16 li H2O 7.78bc 26.67c
15 SINPV/16 li H2O 11.11b 57.78b
20 SINPV/16 li H2O 8.89bc 64.44ab
30 ml Selecron/16 li H2O
63.33a 67.78a
Untreated H2O 0.00c 0.00d
Means in a column with the same letter are not significantly different at 5% level
of significance by DMRT
*DAT- days after treatment
Effects of the SINPV Treatments
The mortality of cutworm larvae from the first until the third spray is presented in
Table 2.
Mortality of cutworm larvae during the first spray. It is clearly presented in the
data Table 2 the very low mortality of cutworms in all the SINPV treatments at the rates
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of 5, 10, 15 and 20 larvae/16 li water. The highest so far for the 3 days assessment after
spray was 11.11 and 8.89% which was observed from the 15 and 20 SINPV larvae/16 li
water. The mortality decreased as the rate was reduced to 5 and 10 SINPV larvae/16 li
water equivalent to 7.78 and 7.78%, respectively. While there was no mortality from the
untreated, the mortality was 63.33% from the standard treatment of Selecron.
Six days after first spray, the mortality of cutworm generally increased in all the
SINPV treatments. The highest which was noted from the highest rate of 20 SINPV
larvae/16 li water was 64.44% followed by 57.78% from the 15 SINPV larvae/16 li
water. The mortality from the two lower rates at 10 and 5 SINPV larvae were 26.67% and
24.45% respectively. The mortality from the standard treatment of Selecron was 67.78%.
Mortality of cutworm larvae during the second spray. The mortality of cutworm
larvae further increased in all the treatments of SINPV and the standard treatment of
Selecron. At 3 days after spray, the mortality was 68.89% from the highest rate at 20
SINPV larvae/16 li water, and 65.55% for the 15 SINPV larvae/16 li water. The mortality
from the two lower rates at 10 and 5 SINPV larvae/16 li water was 35.56% and 28.89%
respectively while a mortality of 73.33% was recorded from the treatment of Selecron.
Table 2. Mortality (%) of cutworm larvae during the first, second and third treatment
application
TREATMENT
1st SPRAY
2nd SPRAY
3rd SPRAY
(Rates)
3 DAT 6 DAT 3 DAT 6 DAT 3 DAT 6 DAT
5 SINPV/16
7.78bc 24.45c 28.89d 28.89d 28.89d 28.89c
li H2O
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10 SINPV/16
7.78bc 26.67c 35.56c 36.67c 36.67c 36.67c
li H2O
15 SINPV/16
11.11b 57.78b 65.55b 66.67b 67.78b 67.78b
li H2O
20 SINPV/16
8.89bc 64.44ab 68.89ab 68.89ab 68.89b 71.11ab
li H2O
30 ml Selecron/16
63.33a 67.78a 73.33a 75.56a 76.67a 76.67a
li H2O
Untreated 0.00c 0.00d 0.00e 0.00e 0.00e 0.00d
Means in a column with the same letter are not significantly different at 5% level
of significance by DMRT
*DAT- days after treatment
Six days after second spray, the mortality of cutworm larvae from the highest rate
of 20 SINPV larvae/16 li water was 68.89% and 66.67% from the rate of 15 SINPV
larvae/16 li water. The mortality for the rates of 10 SINPV larvae/16 li water was 36.67%
while in the lowest rate at 5 SINPV larvae/16 li water was 28.89%. The mortality from
the treatment of Selecron was 75.56%.
Mortality of cutworm larvae during the third spray. The mortality of cutworm
larvae (Figure 5) from the highest rate of 20 SINPV larvae/16 li water 3 days after the
third spray was 68.89% and a mortality of 67.78 % from the rate of 15 SINPV larvae/16
li water. The mortality from the two lower rates at 10 and 5 SINPV larvae/16 li water
were 36.67 and 28.89% respectively and 76.67% from standard treatment of Selecron.
Six days after the last treatment and last data gatherings, the trend of results were
likewise more or less similar. The mortality from highest rate of SINPV at 20 larvae/16 li
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water was 71.11% while the mortality from the three lower rates at 15, 10 and 5 SINPV
larvae/16 li water were 67.78, 36.67, and 28.89% respectively. The mortality from the
standard treatment of Selecron was 76.67%.
Figure 5. Appearance of infected cutworms caused by SINPV treatments
Degree of Cutworm Damage
The assessed damage in cabbage caused by cutworm is presented in Table 3. As
early as the first treatment application, all the treatments of SINPV, the standard
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treatment of Selecron and the untreated were rated slightly damaged. On the other hand,
as time went by and the application of SINPV and the standard Selecron progresses,
damage differences were noted. The highest rates of SINPV at 20 and 15 larvae/16 li
water were slightly damaged comparable with the treatment of Selecron. The lowest
dosage rate of SINPV at 5 larvae/16 li water was moderately damaged while the
untreated was severely damaged.
Table 3. Degree of damage caused by cutworm as affected by the treatments
TREATMENT
3 DAT
10 DAT
20 DAT
(Rates)
5 SINPV/16 li H2O 3.00a 3.00b 5.00b
10 SINPV/16 li H2O 3.00a 3.00b 4.33bc
15 SINPV/16 li H2O 3.00a 3.00b 3.67cd
20 SINPV/16 li H2O 3.00a 3.00b 3.00d
30 ml Selecron/16 li H2O 3.00a 3.00b 3.00d
Untreated 3.67a 5.67a 9.00a
Means in a column with the same letter are not significantly different at 5% level
of significance by DMRT
* The first treatment was applied 30 days after transplanting
* DAT- days after treatments
Marketable Yield (%)
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The percent marketable yield is presented in Table 4. Highest marketable yield
equivalent to 91.67% was recorded from the standard treatment of Selecron. Marketable
yields equivalent to 89.67 and 83.00% were recorded from the treatments of 20 and 15
SINPV larvae/16 li water, respectively. Percent marketable yields were numerically
lower in comparison with the treatment of Selecron but statistically, they were
insignificant. The percent marketable yield from the 10 SINPV larvae/16 li water was
62.00% and 53% from 5 SINPV larvae/16 li water.
Due to severe damaged caused by cutworm, marketable yield was not harvested
from the untreated.
Table 4. Marketable yield (%) as affected by the treatments of SINPV
TREATMENT
MEAN
(Rates)
5 SINPV/16 li H2O
53. 67b
10 SINPV/16 li H2O
62.00b
15 SINPV/16 li H2O
83.00a
20 SINPV/16 li H2O
89.67a
30 ml Selecron/16 li H2O
91.67a
Untreated
0.00c
Means with the same letter are not significantly different at 5% level of
significance by DMRT
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Mortality (%) of Adult Diadegma
The mortality of adult Diadegma is presented in Table 5. It is clearly presented in
the data table the absence of dead adult Diadegma from the treatment of SINPV similar
with the untreated. The results imply that SINPV does not harm adult Diadegma when
applied in cabbage for the control of cutworm. On the other hand, the standard Selecron
is extremely toxic to adult Diadegma brought about by the mortality of the parasitoid to
as high as 100%. The results likewise imply that the use of the said insecticide in the field
for the control of DBM may endanger the parasitoid Diadegma.
Table 5. Mortality (%) of adult Diadegma after exposure from the treatments of SINPV
and Selecron
TREATMENT
RATE
24 HAT
48 HAT
72 HAT
SINPV
20 larvae/16 li H2O 0.00b 0.00b 0.00b
Selecron 30
ml/16
li
H2O 93.
33a 100.00a 100.00a
Untreated ___
0.00b 0.00b 0.00b
* HAT- hours after treatment
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SUMMARY, CONCLUSIONS AND RECOMMENDATION
Summary
The study was conducted at Buyacaoan, Buguias, Benguet from July to
November 2010, a place in Buguias where cabbage is widely planted and where the
insect cutworm is one of the most injurious pest’s insect. This study was conducted
purposely to determine the number of Spodoptera litura Nucleopolyhedrovirus (SINPV)
larvae effective against common cutworm larvae, and to determine should SINPV has
harm effect on adult Diadegma, a parasitoid of diamondback moth.
Thirty early second instar healthy cutworm larvae were released on the cabbage
plants enclosed with nets and sprayed with the treatments which are as follows; 5, 10, 15,
20 SINPV larvae/ 16 li water. Selecron 50 EC at the rate of 30 ml/16 li water was the
standard insecticide. Untreated cutworm larvae were included as the basis for
comparison.
The mortality of cutworm larvae from SINPV treatments was 71.11% at 20
larvae/16 li water, followed by 67.78% on the treatment of 15 SINPV larvae/16 li water
and 36.67% on the treatment of 10 SINPV larvae/16 li water. The treatment of 5 SINPV
larvae/16 li water has the lowest level of mortality equivalent to 28.89% while a mortality
of 76.67 on the standard treatment of Selecron the mortality recorded was 76.67%.
The two highest rates of SINPV at 20 and 15 larvae/16 li water were slightly
damaged comparable with the treatment of Selecron. The two lower dosage rate of
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SINPV at 10 and 5 larvae/16 li water was moderately damaged while the untreated was
severely damaged.
The two highest rates of SINPV treatments from 15 to 20 NPV larvae/16 li water
had the highest percentage of marketable yield equivalent to 83.00 and 89.67%
comparable with the standard treatment of Selecron which was 91.67%. The marketable
yield decreased significantly as the rates of SINPV treatments was reduced to 5 and 10
SINPV larvae/16 li water. Marketable yield was not harvested from the untreated.
Mortality of adult Diadegma was not noted in all the SINPV treatments similar
with the untreated. On the other hand, mortality of 100% was recorded from the standard
treatment of Selecron.
Conclusions and Recommendation
It is concluded that microbial insecticide like SINPV has the efficacy against
cutworm of cabbage comparable to Selecron 50 EC. The SINPV rate of 20 and 15
larvae/16 li water are effective against cutworm. SINPV is not toxic to adult Diadegma.
SINPV is recommended for the control of cutworm in cabbage.
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efficacy of nuclear polyhedrosis virus (NVP) and Bacillus thuringiensis (BT) for
Spodoptera control in Yellow Granex onions. Philippine Ent. 13(2): 159-168.
PODGWAITE, J. D., K. S. SHIELDS, R. T. ZERILLO and R. B. BUEN. 1979.
Environmental persistence of the nuclearpolyhedrosis virus of the gypsy moth,
Lymantria dispar. Environmental Entomology. 8:528-536.
RAO, G. V. R., J. A. WIGTMAN and D. V. R. RAO. 1989. Threshold temperatures and
thermal requirement for the development of Spodoptera litura. Environmental
Entomology.
18:548-551
SCHMUTTER, H. 1969. Pest of crops in Northeast and Central Africa. Germany: Gustav
Fischer Verlag: Pp. 186-188.
VAN HUIS, A. 1989. Integrated management of insect pests in tropical crops. Vol. I. G:
50-110.
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
24
APPENDICES
Appendix Table 1. Mortality (%) of cutworm larvae 3 days after the first treatment
application
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
5 SINPV/16 li
6.67 6.67 10.00 23.34 7.78
H2O
2
10 SINPV/16 li
10.00 10.00 3.33 23.33 7.78
H2O
3
15 SINPV/16 li
16.67 10.00 6.67 33.34 11.11
H2O
4
20 SINPV/16 li
13.33 3.33 10.00 26.66 8.89
H2O
5 30
ml
Selecron/16
56.67 63.33 70.00 190 63.33
li H2O
6
Untreated 0.00
0.00
0.00
0.00
0.00
ANALYSIS OF VARIANCE
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
VARIANCE
OF
SQUARES
SQUARES
FREEDOM
Model
7
8122.827217 1160.403888
52.52**
< .0001
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
25
Block
2
8.658033 4.329017
0.20
0.8252
Treatment 5
8114.169183 1622.833837
73.45
<
.0001
Error
10
220.956833 22.095683
CORRECTED
17 8343.784050
TOTAL
**Highly Significant
Coefficient of variation = 28.52020%
Appendix Table 2. Mortality (%) of cutworm larvae 6 days after the first treatment
application
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
5 SINPV/16 li
30.00 16.67 26.67 73.34 24.45
H2O
2
10 SINPV/16 li
30.00 20.00 30.00 80.00 26.67
H2O
3
15 SINPV/16 li
63.33 50.00 60.00 173.33 57.78
H2O
4
20 SINPV/16 li
73.33 56.67 63.33 193.33 64.44
H2O
5 30
ml
Selecron/16
63.33 70.00 70.00 203.33 67.78
li H2O
6
Untreated 0.00
0.00
0.00
0.00
0.00
ANALYSIS OF VARIANCE
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
VARIANCE
OF
SQUARES
SQUARES
FREEDOM
Model 7
11314.63462 1616.37637
70.78**
< .0001
Block
2
201.10990 100.55495
4.40
0.0425
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
26
Treatment 5
11113.52472 2222.70494
97.33
< .0001
Error
10
228.37163 22.83716
CORRECTED
17 11543.00625
TOTAL
**Highly Significant
Coefficient of variation = 11.89206%
Appendix Table 3. Mortality (%) of cutworm larvae 3 days after the second treatment
application
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
5 SINPV/16 li
30.00 26.67 30.00 86.67 28.89
H2O
2
10 SINPV/16 li
40.00 30.00 36.67 106.67 35.56
H2O
3
15 SINPV/16 li
70.00 63.33 63.33 196.66 65.55
H2O
4
20 SINPV/16 li
76.67 66.67 63.33 206.67 68.89
H2O
5 30
ml
Selecron/16
73.33 70.00 76.67 220.00 73.33
li H2O
6
Untreated 0.00
0.00
0.00
0.00
0.00
ANALYSIS OF VARIANCE
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
VARIANCE
OF
SQUARES
SQUARES
FREEDOM
Model 7
12600.31237 1800.14462 158.29**
< .0001
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
27
Block
2
93.80988 46.90494
4.12
0.0494
Treatment 5
12506.50249 2501.30050 219.96 <
.0001
Error
10
113.71612 11.37161
CORRECTED
17 12714.02849
TOTAL
**Highly Significant
Coefficient of variation = 7.432534%
Appendix Table 4. Mortality (%) of cutworm larvae 6 days after the second treatment
application
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
5 SINPV/16 li
30.00 26.67 30.00 86.67 28.89
H2O
2
10 SINPV/16 li
40.00 30.00 40.00 110.00 36.67
H2O
3
15 SINPV/16 li
70.00 66.67 63.33 200.00 66.67
H2O
4
20 SINPV/16 li
76.67 66.67 63.33 206.67 68.89
H2O
5 30
ml
Selecron/16
73.33 76.67 76.67 226.67 75.56
li H2O
6
Untreated 0.00
0.00
0.00
0.00
0.00
ANALYSIS OF VARIANCE
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
VARIANCE
OF
SQUARES
SQUARES
FREEDOM
Model
7
13009.45188 1858.49313 122.27**
< .0001
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
28
Block
2
48.10743 24.05372
1.58
0.2529
Treatment 5
12961.34445 2592.26889 170.54 <
.0001
Error
10
152.00377 15.20038
CORRECTED
17 13161.45565
TOTAL
**Highly Significant
Coefficient of variation = 8.455053%
Appendix Table 5. Mortality (%) of cutworm larvae 3 days after the third treatment
application
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
5 SINPV/16 li
30.00 26.67 30.00 86.67 28.89
H2O
2
10 SINPV/16 li
40.00 30.00 40.00 110.00 36.67
H2O
3
15 SINPV/16 li
70.00 66.67 66.67 203.34 67.78
H2O
4
20 SINPV/16 li
76.67 66.67 63.33 206.67 68.89
H2O
5 30
ml
Selecron/16
73.33 76.67 80.00 230.00 76.67
li H2O
6
Untreated 0.00
0.00
0.00
0.00
0.00
ANALYSIS OF VARIANCE
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
VARIANCE
OF
SQUARES
SQUARES
FREEDOM
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
29
Model 7
13345.32349 1906.47478 123.44**
< .0001
Block
2
45.62471 22.81236
1.48
0.2741
Treatment 5
13299.69878 2659.93976 172.23 <
.0001
Error
10
154.44202 15.44420
CORRECTED
17 13499.76551
TOTAL
**Highly Significant
Coefficient of variation = 8.454654%
Appendix Table 6. Mortality (%) of cutworm larvae 6 days after the third treatment
application
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
5 SINPV/16 li
30.00 26.67 30.00 86.67 28.89
H2O
2
10 SINPV/16 li
40.00 30.00 40.00 110.00 36.67
H2O
3
15 SINPV/16 li
70.00 66.67 66.67 203.34 67.78
H2O
4
20 SINPV/16 li
80.00 70.00 63.33 213.33 71.11
H2O
5 30
ml
Selecron/16
73.33 76.67 80.00 230.00 76.67
li H2O
6
Untreated 0.00
0.00
0.00
0.00
0.00
ANALYSIS OF VARIANCE
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
30
VARIANCE OF SQUARES SQUARES
FREEDOM
Model 7
13656.11979 1950.87426
98.10**
< .0001
Block
2
45.62841
22.81421
1.15
0.3560
Treatment 5
13610.49138 2722.09828 136.88 <
.0001
Error
10
198.86052 19.88605
CORRECTED
17 13854.98031
TOTAL
**Highly Significant
Coefficient of variation = 9.517965%
Appendix Table 7. Degree of damage caused by cutworm larvae 3 days after the
treatment
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
5 SINPV/16 li
3 3 3 9 3.00
H2O
2
10 SINPV/16 li
3 3 3 9 3.00
H2O
3
15 SINPV/16 li
3 3 3 9 3.00
H2O
4
20 SINPV/16 li
3 3 3 9 3.00
H2O
5 30
ml
Selecron/16
3 3 3 9 3.00
li H2O
6
Untreated 3 3 5 11
3.67
ANALYSIS OF VARIANCE
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
31
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
VARIANCE
OF
SQUARES
SQUARES
FREEDOM
Model 7
1.55555556
0.22222222
1.00ns
0.4834
Block 2
0.44444444
0.22222222
1.00
0.4019
Treatment 5
1.11111111
0.22222222 1.00 0.4651
Error 10
2.22222222
0.22222222
CORRECTED
17 3.77777778
TOTAL
ns Not Significant
Coefficient of variation = 15.15229%
Appendix Table 8. Degree of damage caused by cutworm larvae 10 days after the
treatments
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
5 SINPV/16 li
3 3 3 9 3.00
H2O
2
10 SINPV/16 li
3 3 3 9 3.00
H2O
3
15 SINPV/16 li
3 3 3 9 3.00
H2O
4
20 SINPV/16 li
3 3 3 9 3.00
H2O
5 30
ml
Selecron/16
3 3 3 9 3.00
li H2O
6
Untreated 5 5 7 17
5.67
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
32
ANALYSIS OF VARIANCE
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
VARIANCE
OF
SQUARES
SQUARES
FREEDOM
Model 7
18.22222222 2.60317460
11.71*
0.0004
Block
2
0.44444444 0.22222222
1.00
0.4019
Treatment 5
17.77777778 3.55555556 16.00 0.0002
Error
10
2.22222222 0.22222222
CORRECTED
17 20.44444444
TOTAL
*Significant Coefficient of variation = 13.68594%
Appendix Table 9. Degree of damage caused by cutworm larvae 20 days after the
treatments
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
5 SINPV/16 li
5 5 5 15 5.00
H2O
2
10 SINPV/16 li
5 5 3 13 4.33
H2O
3
15 SINPV/16 li
3 5 3 11 3.67
H2O
4
20 SINPV/16 li
3 3 3 9 3.00
H2O
5 30
ml
Selecron/16
3 3 3 9 3.00
li H2O
6
Untreated 9 9 9 27
9.00
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
33
ANALYSIS OF VARIANCE
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
VARIANCE
OF
SQUARES
SQUARES
FREEDOM
Model 7
78.00000000 11.14285714
27.86**
< .0001
Block
2
1.33333333 0.66666667
1.67
0.2373
Treatment 5
76.66666667 15.33333333
38.33 <
.0001
Error
10
4.00000000 0.40000000
CORRECTED
17 82.0000000
TOTAL
**Highly Significant
Coefficient of variation = 13.55262%
Appendix Table 10. Marketable yield (%) as affected by the treatments of SINPV
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
5 SINPV/16 li
45 56 60 161 53.67
H2O
2
10 SINPV/16 li
53 60 73 186 62.00
H2O
3
15 SINPV/16 li
84 85 80 249 83.00
H2O
4
20 SINPV/16 li
90 87 92 269 89.67
H2O
5 30
ml
Selecron/16
90 95 90 275 91.67
li H2O
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
34
6
Untreated 0.00
0.00
0.00
0.00
0.00
ANALYSIS OF VARIANCE
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
VARIANCE
OF
SQUARES
SQUARES
FREEDOM
Model 7
18061.00000 2580.14286
93.15**
< .0001
Block
2
93.00000 46.50000
1.68
0.2352
Treatment 5
17968.00000 3593.60000 129.73 <
.0001
Error
10
277.00000 27.70000
CORRECTED
17 18338.00000
TOTAL
**Highly Significant
Coefficient of variation = 8.310125%
Appendix Table 11. Mortality (%) of adult Diadegma after 24 hours of exposure from the
treatments of SINPV and Selecron
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
20 SINPV/16 li
0.00 0.00 0.00 0.00 0.00
H2O
2 30
ml
Selecron/16
90.00 100.00 90.00 280 93.33
li H2O
3
Untreated 0.00
0.00
0.00
0.00
0.00
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
35
ANALYSIS OF VARIANCE
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
VARIANCE
OF
SQUARES
SQUARES
FREEDOM
Model 2
17422.22222 8711.11111
784.00*
< .0001
Treatment 2
17422.22222 8711.11111 784.00 <
.0001
Error
6
66.66667 11.11111
CORRECTED
8 17488.88889
TOTAL
*Significant Coefficient of variation = 10.71429%
Appendix Table 12. Mortality (%) of adult Diadegma after 48 hours of exposure from the
treatments of SINPV and Selecron
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
20 SINPV/16 li
0.00 0.00 0.00 0.00 0.00
H2O
2 30
ml
Selecron/16
100.00 100.00 100.00 300.00 93.33
li H2O
3
Untreated 0.00
0.00
0.00
0.00
0.00
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
36
ANALYSIS OF VARIANCE
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
VARIANCE
OF
SQUARES
SQUARES
FREEDOM
Model 2
20000.00000 10000.00000
Infty*
< .0001
Treatment 2
20000.00000 10000.00000
Infty <
.0001
Error
6
0.00000 0.00000
CORRECTED
8 20000.00000
TOTAL
*Significant
Coefficient of variation = 0
Appendix Table 13. Mortality (%) of adult Diadegma after 72 hours of exposure from the
treatments of SINPV and Selecron
REPLICATIONS
TREATMENT RATES
I II III
TOTAL
MEAN
1
20 SINPV/16 li
0.00 0.00 0.00 0.00 0.00
H2O
2 30
ml
Selecron/16
100.00 100.00 100.00 300.00 93.33
li H2O
3
Untreated 0.00
0.00
0.00
0.00
0.00
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
37
ANALYSIS OF VARIANCE
SOURCE OF
DEGREE
SUM OF
MEAN OF
F VALUE
Pr > F
VARIANCE
OF
SQUARES
SQUARES
FREEDOM
Model 2
20000.00000 10000.00000
Infty*
< .0001
Treatment 2
20000.00000 10000.00000
Infty <
.0001
Error
6
0.00000 0.00000
CORRECTED
8 20000.00000
TOTAL
*Significant
Coefficient of variation = 0
Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm on Head
Cabbage in Buguias, Benguet / JIRLDANMYR DIONISIO D. IGUALDO. 2011
Document Outline
- Field Efficacy Evaluation of Nucleopolyhedrovirus Against Common Cutworm (Spodoptera lituraFabr.) on Head Cabbage in Buguias, Benguet
- BIBLIOGRAPHY
- ABSTRACT
- TABLE OF CONTENTS
- INTRODUCTION
- REVIEW OF LITERATURE
- MATERIALS AND METHODS
- SUMMARY, CONCLUSIONS AND RECOMMENDATION
- LITERATURE CITED
- APPENDICES